To Örebro University

oru.seÖrebro University Publications
Change search
Refine search result
1 - 20 of 20
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Axelrad, Jordan E.
    et al.
    Division of Gastroenterology, Department of Medicine, NYU School of Medicine, New York NY, USA.
    Sachs, Michael C.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK; Department of Medicine, Columbia University College of Physicians and Surgeons, New York NY, USA.
    Olén, Ola
    Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Sachs’ Children and Youth Hospital, Stockholm South General Hospital, Stockholm, Sweden; Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.
    A Novel Method for Quantifying Intestinal Inflammatory Burden in Inflammatory Bowel Disease Using Register Data2020In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 12, p. 1059-1072Article in journal (Refereed)
    Abstract [en]

    Background: The Swedish Quality Register for Inflammatory Bowel Disease (SWIBREG) contains clinical data for the study of inflammatory bowel disease (IBD). The Epidemiology Strengthened by histoPathology Reports in Sweden (ESPRESSO) cohort was recently established for the study of gastrointestinal histopathology. We aimed to develop and validate a histology score from ESPRESSO using clinical information from SWIBREG, and secondarily, to evaluate the association of the score on IBD-related hospitalization.

    Methods: In a nationwide, population-based cohort study of patients with IBD during 1969-2017, we linked endoscopic inflammation in SWIBREG with histologic inflammation in ESPRESSO. We established a clinically interpretable model for predicting the endoscopic score from histology using scalable Bayesian rule lists to define a SNOMED-based histology score applicable to the ESPRESSO cohort. We also assessed the impact of baseline endoscopic and histology scores on time to IBD-related hospitalization.

    Results: We identified 5225 individuals with IBD comprising 11,051 endoscopic assessments in SWIBREG linked to a histopathology record in ESPRESSO. We created predictive models to calculate a SNOMED-based histology score which predicted the endoscopic score. Split-sample validated areas under the ROC curves for the score predicting a non-zero endoscopic score were 0.80 (0.78-0.81) in UC, 0.70 (0.68-0.72) in CD, and 0.76 (0.73-0.78) in IBD-U. In a subset of 2741 individuals with an initial IBD diagnosis and a corresponding record in ESPRESSO with an endoscopic assessment in SWIBREG, the baseline endoscopic and histology scores were associated with time to IBD-related hospitalization (endoscopy log-rank UC p<0.001, CD p=0.020, IBD-U p<0.001; histology log-rank UC p=0.018, CD p=0.960, IBD-U p=0.034).

    Conclusion: Histopathology data in ESPRESSO accurately predict endoscopic scores in SWIBREG. Baseline endoscopic and histologic scores were associated with time to IBD-related hospitalization, particularly in UC. The SNOMED-based histology score can be used as a measure of disease activity in future register-based IBD studies.

  • 2.
    Balla, Hajnal Zsuzsanna
    et al.
    Department of Neurology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Cao, Yang
    Örebro University, School of Medical Sciences. Örebro University Hospital. Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Ström, Jakob O.
    Örebro University, School of Medical Sciences. Department of Neurology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
    Effect of Beta-Blockers on Stroke Outcome: A Meta-Analysis2021In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 13, p. 225-236Article, review/survey (Refereed)
    Abstract [en]

    Introduction: Cardiovascular events and infections are common in the acute phase after stroke. It has been suggested that these complications may be associated with excessive sympathetic activation due to the stroke, and that beta-adrenergic antagonists (beta-blockers) therefore may be beneficial.

    Aim: The aim of the current meta-analysis was to investigate the association between beta-blocker treatment in acute stroke and the three outcomes: mortality, functional outcome and post-stroke infections.

    Methods: statistics. Random effect model was used when heterogeneity presented among studies; otherwise, a fixed-effect model was used. Publication bias was assessed using Egger's test and by visually inspecting funnel plots.

    Results: A total of 20 studies were eligible for at least one of the three outcomes. Two of the included studies were randomized controlled trials and 18 were observational studies. Quality assessments indicated that the risk of bias was moderate. The meta-analysis found no significant association between treatment with beta-blockers and any of the three outcomes. The studies analyzed for the outcomes mortality and infection were heterogeneous, while studies analyzed for functional outcome were homogeneous. The articles analyzed for mortality showed signs of publication bias.

    Conclusion: The lack of significant effects in the current meta-analysis, comprising more than 100,000 patients, does not support the proposed beneficial effects of beta-blockers in the acute phase of stroke.

  • 3.
    Bergman, David
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Hagström, Hannes
    Division of Hepatology, Department of Upper GI Diseases, Karolinska University Hospital, Stockholm, Sweden; Clinical Epidemiology Unit, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden; Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden.
    Capusan, Andrea Johansson
    Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Psychiatry in Linköping, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
    Mårild, Karl
    Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg, Sweden; Department of Pediatric Gastroenterology, Queen Silvia Children’s Hospital, Gothenburg, Sweden.
    Nyberg, Fredrik
    School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Sundquist, Kristina
    Center for Primary Health Care Research, Department of Clinical Sciences, Lund University, Malmö, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK; Department of Medicine, Columbia University College of Physicians and Surgeons, New York NY, USA .
    Incidence of ICD-Based Diagnoses of Alcohol-Related Disorders and Diseases from Swedish Nationwide Registers and Suggestions for Coding2020In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 12, p. 1433-1442Article in journal (Refereed)
    Abstract [en]

    Aim: To improve consistency between register studies in Sweden and ensure valid comparisons of possible changes in alcohol-related disorders and diseases (ARDDs) over time, we propose a definition of ARDDs. Based on this definition, we examined Sweden's incidence rates of ARDDs from 1970 to 2018 in non-primary healthcare settings (inpatient and outpatient).

    Methods: Swedish Society of Epidemiology members were invited to give feedback on the International Classification of Disease (ICD) codes with a potential link to alcohol use. We then calculated age-standardised and age-specific incidence of ARDDs over time according to the National Patient Register, and the lifetime prevalence of ARDDs diagnosed in adults alive in Sweden on Dec 31, 2018.

    Results: Sweden's estimated incidence of ARDDs increased substantially after introducing the new ICD-9 codes in 1987. In the past 10 years (2009-2018), the incidence of ARDDs has been stable (males: 110/100,000 person-years, females: 49/100,000 person-years). Requiring at least two ICD records for diagnosed ARDDs led to a somewhat lower incidence of ARDDs (males: 71 per 100,000 person-years, females: 29 per 100,000 person-years). In Sweden, the lifetime prevalence of diagnosed ARDDs in adults on Dec 31, 2018, was 1.9% (95% CI=1.9-1.9). Conclusion: In this nationwide study, we found an incidence of ARDDs of 50-100/100,000 person-years. In 2018, 1 in 52 adults in Sweden had been diagnosed with ARDDs in the National Patient Register.

  • 4.
    Chen, Ruoqing
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Fall, Katja
    Örebro University, School of Medical Sciences. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; School of Medical Sciences, Örebro University, Örebro, Sweden.
    Czene, Kamila
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Kennedy, Beatrice
    Örebro University, School of Medical Sciences.
    Valdimarsdottir, Unnur
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Centre of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavík, Iceland; Department of Epidemiology, Harvard TH Chan School of Public Health, Boston MA, USA.
    Fang, Fang
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Impact of parental cancer on IQ, stress resilience, and physical fitness in young men2018In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 10, p. 593-602Article in journal (Refereed)
    Abstract [en]

    Background: A parental cancer diagnosis is a stressful life event, potentially leading to increased risks of mental and physical problems among children. This study aimed to investigate the associations of parental cancer with IQ, stress resilience, and physical fitness of the affected men during early adulthood.

    Materials and methods: In this Swedish population-based study, we included 465,249 men born during 1973-1983 who underwent the military conscription examination around the age of 18 years. We identified cancer diagnoses among the parents of these men from the Cancer Register. IQ, stress resilience, and physical fitness of the men were assessed at the time of conscription and categorized into three levels: low, moderate, and high (reference category). We used multinomial logistic regression to assess the studied associations. Results: Overall, parental cancer was associated with higher risks of low stress resilience (relative risk ratio [RRR]: 1.09 [95% confidence interval (CI) 1.04-1.15]) and low physical fitness (RRR: 1.12 [95% CI 1.05-1.19]). Stronger associations were observed for parental cancer with a poor expected prognosis (low stress resilience: RRR: 1.59 [95% CI 1.31-1.94]; low physical fitness: RRR: 1.45 [95% CI 1.14-1.85]) and for parental death after cancer diagnosis (low stress resilience: RRR: 1.29 [95% CI 1.16-1.43]; low physical fitness: RRR: 1.40 [95% CI 1.23-1.59]). Although there was no overall association between parental cancer and IQ, parental death after cancer diagnosis was associated with a higher risk of low IQ (RRR: 1.11 [95% CI 1.01-1.24]).

    Conclusion: Parental cancer, particularly severe and fatal type, is associated with higher risks of low stress resilience and low physical fitness among men during early adulthood. Men who experienced parental death after cancer diagnosis also have a higher risk of low IQ.

  • 5.
    Everhov, ÅH.
    et al.
    Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden; Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Sachs, M. C.
    Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro University, Örebro, Sweden.
    Khalili, H.
    Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Gastroenterology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
    Askling, J.
    Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Neovius, M.
    Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Myrelid, P.
    Division of Surgery, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden; Department of Surgery, County Council of Östergötland Linköping, Linköping, Sweden.
    Halfvarson, Jonas
    Örebro University, School of Medical Sciences. Department of Gastroenterology.
    Nordenvall, C.
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Center for Digestive Disease, Division of Coloproctology, Karolinska University Hospital, Stockholm, Sweden.
    Söderling, J.
    Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Olén, O.
    Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden; Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Department of Pediatric Gastroenterology and Nutrition, Sachs’ Children and Youth Hospital, Stockholm, Sweden.
    Work loss in relation to pharmacological and surgical treatment for Crohn’s disease: A population-based cohort study2020In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 12, p. 273-285Article in journal (Refereed)
    Abstract [en]

    Purpose: Patients with Crohn’s disease have increased work loss. We aimed to describe changes in work ability in relation to pharmacological and surgical treatments.

    Patients and Methods: We linked data from the Swedish National Patient Register, The Swedish Quality Register for Inflammatory Bowel Disease SWIBREG, The Prescribed Drug Register, The Longitudinal Integrated Database for Health Insurance and Labour Market Studies, and the Social Insurance Database. We identified working-age (19–59 years) patients with incident Crohn’s disease 2006–2013 and population comparator subjects matched by sex, birth year, region, and education level. We assessed the number of lost workdays due to sick leave and disability pension before and after treatments.

    Results: Of 3956 patients (median age 34 years, 51% women), 39% were treated with aminosalicylates, 52% with immunomodulators, 22% with TNF inhibitors, and 18% with intestinal surgery during a median follow-up of 5.3 years. Most patients had no work loss during the study period (median=0 days). For all treatments, the mean number of lost workdays increased during the months before treatment initiation, peaked during the first month of treatment and decreased thereafter, and was heavily influenced by sociodemo-graphic factors and amount of work loss before first Crohn’s disease diagnosis. The mean increase in work loss days compared to pre-therapeutic level was ~3 days during the first month of treatment for all pharmacological therapies and 11 days for intestinal surgery. Three months after treatment initiation, 88% of patients treated surgically and 90–92% of patients treated pharmacologically had the same amount of work loss as before treatment start. Median time to return to work was 2 months for all treatments.

    Conclusion: In this regular clinical setting, patients treated surgically had more lost workdays than patients treated pharmacologically, but return to work was similar between all treatments.

  • 6.
    Jarrick, Simon
    et al.
    Örebro University, School of Medical Sciences. Department of Pediatrics, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Lundberg, Sigrid
    Karolinska University Hospital, Stockholm, Sweden; Karolinska Institutet, Stockholm, Sweden.
    Welander, Adina
    Boston Consulting Group, Stockholm, Sweden; Karolinska Institutet, Stockholm, Sweden.
    Fored, Michael C.
    Karolinska Institutet, Stockholm, Sweden.
    Ludvigsson, Jonas F.
    Örebro University Hospital, Örebro, Sweden; Karolinska Institutet, Stockholm, Sweden; University of Nottingham, Nottingham, England.
    Clinical validation of immunoglobulin A nephropathy diagnosis in Swedish biopsy registers2017In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 9, p. 67-73Article in journal (Refereed)
    Abstract [en]

    Aims: The aims of this study were to validate the diagnosis of IgA nephropathy (IgAN) in Swedish biopsy registers against patient charts and to describe the clinical characteristics of patients with a biopsy indicating IgAN.

    Methods: This is a population-based cohort study. Out of 4,069 individuals with a renal biopsy consistent with IgAN (biopsies performed in 1974-2011), this study reviewed patient charts of a random subset of 127 individuals. Clinical and biopsy characteristics at the time of biopsy were evaluated, and positive predictive values (PPV) were calculated with 95% confidence intervals (CI).

    Results: Out of 127 individuals with a renal biopsy consistent with IgAN, 121 had a likely or confirmed clinical diagnosis of IgAN, primary or secondary to Henoch-Schonlein purpura, yielding a PPV of 95% (95% CI =92%-99%). The median age at biopsy was 39 years (range: 4-79 years); seven patients (6%) were <16 years. The male to female ratio was 2.8:1. The most common causes for consultation were macroscopic hematuria (n=37; 29%), screening (n=33; 26%), and purpura (n=14, 11%). In patients with available data, the median creatinine level was 104 mu mol/L (range 26-986 mu mol/L, n=110) and glomerular filtration rate 75 mL/min/1.73m(2) (range 5-173 mL/min/1.73m(2), n=114). Hypertension was noted in 59 (46%) individuals. IgA deposits were reported in 97% of the biopsy records (n= 123), mesangial hypercellularity in 76% (n= 96), C3 deposits in 89% (n=113), and C1q deposits in 12% (n=15). Conclusion: A histologic diagnosis of IgAN has a high PPV for a diagnosis of IgAN confirmed by review of patient charts.

  • 7.
    Kuja-Halkola, Ralf
    et al.
    Department Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Lebwohl, Benjamin
    Department Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Medicine, Celiac Disease Center, Columbia University Medical Center, Columbia University, New York NY, USA.
    Halfvarson, Jonas
    Örebro University, School of Medical Sciences. Department of Gastroenterology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Emilsson, Louise
    Department of Health Management and Health Economy, Institute of Health and Society, University of Oslo, Oslo, Norway; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston MA, USA; Centre for Clinical Research, Vårdcentralen Värmlands Nysäter, County Council of Värmland, Karlstad, Sweden.
    Magnusson, Patrik K.
    Department Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Dept Med Epidemiol & Biostat, Karolinska Inst, Stockholm, Sweden; Dept Med, Celiac Dis Ctr, Columbia Univ, New York NY, USA; Dept Pediat, Örebro Univ Hosp, Örebro, Sweden; City Hosp, Sch Med, Div Epidemiol & Publ Hlth, Univ Nottingham, Nottingham, England.
    Birth weight, sex, and celiac disease: a nationwide twin study2017In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 9, p. 567-577Article in journal (Refereed)
    Abstract [en]

    Objective: Earlier research suggests that birth weight may be associated with celiac disease (CD), but the direction of association has been unclear potentially due to confounding effect from genetic and intrafamilial factors. Through within-twin analyses, we aimed to minimize confounding effects such as twins that share genetic and early environmental exposures.

    Materials and methods: Using the Swedish Twin Registry, we examined the birth weight of 146,830 twins according to the CD status. CD was defined as having villous atrophy according to a small intestinal biopsy reports.

    Results: The prevalence of diagnosed CD was 0.5% (n=669), and we included 407 discordant pairs of CD-non-CD twins. Comparing the 669 CD patients with non-CD twins, the association between birth weight and future CD was not statistically significant (odds ratio [OR] per 1000 g increase in birth weight: 1.16; 95% confidence interval [CI]=0.97-1.38). In males, the association was positive and statistically significant (OR=1.50; 95% CI=1.11-2.02). However, the association was not significant in within-pair analyses for both dizygotic and monozygotic twins and for both sexes.

    Conclusion: This population-based study found that in male twins, higher birth weight was associated with higher risk of CD. However, when comparing discordant twin pairs in within-twin pair analyses, there was no statistically significant association between birth weight, intrauterine growth, and future risk of CD.

  • 8.
    Laugesen, Kristina
    et al.
    Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden.
    Schmidt, Morten
    Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
    Gissler, Mika
    Information Services Department, THL Finnish Institute for Health and Welfare, Helsinki, Finland; Research Centre for Child Psychiatry, University of Turku, Turku, Finland; Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden; Region Stockholm, Academic Primary Health Care Centre, Stockholm, Sweden.
    Valdimarsdottir, Unnur Anna
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Center of Public Health Science, Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Epidemiology, Harvard TH Chan School of Public Health, Boston MA, USA.
    Lunde, Astrid
    Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
    Sørensen, Henrik Toft
    Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; KOR, The Danish Advisory Board on Register Based Research, the Danish e-infrastructure Cooperation, Copenhagen, Denmark.
    Nordic Health Registry-Based Research: A Review of Health Care Systems and Key Registries2021In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 13, p. 533-554Article, review/survey (Refereed)
    Abstract [en]

    The Nordic countries are Denmark, Finland, Iceland, Norway, and Sweden and comprise a total population of approximately 27 million. The countries provide unique oppor-tunities for joint health registry-based research in large populations with long and complete follow-up, facilitated by shared features, such as the tax-funded and public health care systems, the similar population-based registries, and the personal identity number as unique identifier of all citizens. In this review, we provide an introduction to the health care systems, key registries, and how to navigate the practical and ethical aspects of setting up such studies. For each country, we provide an overview of population statistics and health care expenditures, and describe the operational and administrative organization of the health care system. The Nordic registries provide population-based, routine, and prospective data on individuals lives and health with virtually complete follow-up and exact censoring information. We briefly describe the total population registries, birth registries, patient registries, cancer registries, prescription registries, and causes of death registries with a focus on period of coverage, selected key variables, and potential limitations. Lastly, we discuss some practical and legal perspectives. The potential of joint research is not fully exploited, mainly due to legal and practical difficulties in, for example, cross-border sharing of data. Future tasks include clear and transparent legal pathways and a framework by which practical aspects are facilitated.

  • 9.
    Lebwohl, Benjamin
    et al.
    Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York NY, USA.
    Larsson, Emma
    Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
    Söderling, Jonas
    Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden.
    Roelstraete, Bjorn
    Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden.
    Murray, Joseph A.
    Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester MN, USA.
    Green, Peter H. R.
    Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York NY, USA.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York NY, USA; Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro University, Örebro, Sweden.
    Risk of Severe Covid-19 in Patients with Celiac Disease: A Population-Based Cohort Study2021In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 13, p. 121-130Article in journal (Refereed)
    Abstract [en]

    Background: Patients with celiac disease (CeD) are at increased risk of certain viral infections and of pneumococcal pneumonia, raising concerns that they may be susceptible to severe coronavirus disease 2019 (Covid-19). We aimed to quantify the association between CeD and severe outcomes related to Covid-19.

    Methods: We performed a population-based cohort study, identifying individuals with CeD in Sweden, as defined by small intestinal villus atrophy diagnosed at all (n=28) Swedish pathology departments during the years spanning 1969-2017, and alive on February 1, 2020. We compared these patients to controls matched by sex, age, county, and calendar period. We performed Cox proportional hazards with follow-up through July 31, 2020, assessing risk of 1) hospital admission with a primary diagnosis of laboratory-confirmed Covid-19 (co-primary outcome); and 2) severe disease as defined by admission to intensive care unit and/or death attributed to Covid-19 (co-primary outcome).

    Results: Among patients with CeD (n=40,963) and controls (n=183,892), the risk of hospital admission for Covid-19 was 2.9 and 2.2 per 1000 person-years respectively. After adjusting for comorbidities, the risk of hospitalization for Covid-19 was not significantly increased in patients with CeD (HR 1.10; 95% CI 0.80-1.50), nor was the risk of severe Covid-19 increased (HR 0.97; 95% CI 0.59-1.59). Results were similarly null when we compared CeD patients to their non-CeD siblings with regard to these outcomes. Among all patients with CeD and controls hospitalized with a diagnosis of Covid-19 (n=58 and n=202, respectively), there was no significant difference in mortality (HR for CeD compared to controls 0.96; 95% CI 0.46-2.02).

    Conclusion: In this population-based study, CeD was not associated with an increased risk of hospitalization for Covid-19 or intensive care unit and/or death attributed to Covid-19.

  • 10.
    Ludvigsson, Jonas F.
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK; Department of Medicine, Columbia University College of Physicians and Surgeons, New York NY, USA.
    Appelros, Peter
    University Health Care Research Center, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Askling, Johan
    Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Rheumatology, Theme Inflammation and Infection, Karolinska University Hospital, Stockholm, Sweden.
    Byberg, Liisa
    Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
    Carrero, Juan-Jesus
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Ekström, Anna Mia
    Global & Sexual Health Research Group (GloSH), Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden; Faculty of Medicine, Department of Clinical Sciences Lund, Respiratory Medicine and Allergology, Lund University, Lund, Sweden.
    Ekström, Magnus
    Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.
    Smedby, Karin Ekström
    Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Hagström, Hannes
    Division of Hepatology, Department of Upper GI Diseases, Karolinska University Hospital, Stockholm, Sweden; Clinical Epidemiology Division, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden; Department of Medicine, Karolinska Huddinge, Institutet, Stockholm, Sweden.
    James, Stefan
    Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden; Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden.
    Järvholm, Bengt
    Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
    Michaelsson, Karl
    Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
    Pedersen, Nancy L.
    Department of Medical Epidemiology, Karolinska Institutet, Stockholm, Sweden.
    Sundelin, Helene
    Neuropediatric Unit, Department of Women’s and Children’s Health, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden; Division of Children’s and Women’s Health, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
    Sundquist, Kristina
    Center for Primary Health Care Research, Department of Clinical Sciences, Malmö, Lund University, Lund, Sweden.
    Sundström, Johan
    Department of Medical Sciences, Uppsala University, Uppsala, Sweden; The George Institute for Global Health, University of New South Wales, Sydney, Australia; Department of Family Medicine and Community Health, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York NY, USA.
    Adaptation of the Charlson Comorbidity Index for Register-Based Research in Sweden2021In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 13, p. 21-41Article in journal (Refereed)
    Abstract [en]

    Purpose: Comorbidity indices are often used to measure comorbidities in register-based research. We aimed to adapt the Charlson comorbidity index (CCI) to a Swedish setting.

    Methods: Four versions of the CCI were compared and evaluated by disease-specific experts.

    Results: We created a cohesive coding system for CCI to 1) harmonize the content between different international classification of disease codes (ICD-7,8,9,10), 2) delete incorrect codes, 3) enhance the distinction between mild, moderate or severe disease (and between diabetes with and without end-organ damage), 4) minimize duplication of codes, and 5) briefly explain the meaning of individual codes in writing.

    Conclusion: This work may provide an integrated and efficient coding algorithm for CCI to be used in medical register-based research in Sweden.

  • 11.
    Ludvigsson, Jonas F.
    et al.
    Örebro University Hospital. Dept Med Epidemiol & Biostat, Karolinska Inst, Stockholm, Sweden; Dept Pediat, Örebro Univ Hosp, Örebro, Sweden.
    Haberg, Siri E.
    Norwegian Inst Publ Hlth, Oslo, Norway.
    Knudsen, Gun Peggy
    Norwegian Inst Publ Hlth, Oslo, Norway.
    Lafolie, Pierre
    Clin Pharmacol Unit, Dept Med, Karolinska Inst, Stockholm, Sweden; Stockholm Reg Eth Review Board, Karolinska Inst, Stockholm, Sweden.
    Zoega, Helga
    Fac Med, Ctr Publ Hlth Sci, Univ Iceland, Reykjavik, Iceland.
    Sarkkola, Catharina
    Genet Epidemiol Grp, Folkhälsan Res Ctr, Helsinki, Finland.
    von Kraemer, Stephanie
    Genet Epidemiol Grp, Folkhälsan Res Ctr, Helsinki, Finland.
    Weiderpass, Elisabete
    Dept Med Epidemiol & Biostat, Karolinska Inst, Stockholm, Sweden; Genet Epidemiol Grp, Folkhälsan Res Ctr, Helsinki, Finland; Fac Hlth Sci, Dept Community Med, Univ Tromsö, Tromsö, Norway; Arctic Univ Norway, Tromsö, Norway; Dept Res, Canc Registry Norway, Oslo, Norway.
    Norgaard, Mette
    Dept Clin Epidemiol, Aarhus Univ Hosp, Aarhus, Denmark.
    Ethical aspects of registry-based research in the Nordic countries2015In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 7, p. 491-507Article, review/survey (Refereed)
    Abstract [en]

    National health care registries in the Nordic countries share many attributes, but different legal and ethical frameworks represent a challenge to promoting effective joint research. Internationally, there is a lack of knowledge about how ethical matters are considered in Nordic registry-based research, and a lack of knowledge about how Nordic ethics committees operate and what is needed to obtain an approval. In this paper, we review ethical aspects of registry-based research, the legal framework, the role of ethics review boards in the Nordic countries, and the structure of the ethics application. We discuss the role of informed consent in registry-based research and how to safeguard the integrity of study participants, including vulnerable subjects and children. Our review also provides information on the different government agencies that contribute registry-based data, and a list of the major health registries in Denmark, Finland, Iceland, Norway, and Sweden. Both ethical values and conditions for registry-based research are similar in the Nordic countries. While Denmark, Finland, Iceland, Norway, and Sweden have chosen different legal frameworks, these differences can be resolved through mutual recognition of ethical applications and by harmonizing the different systems, likely leading to increased collaboration and enlarged studies.

  • 12.
    Ludvigsson, Jonas F.
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Clinical Sciences Building 2, City Hospital, Nottingham, UK; Department of Medicine, Columbia University College of Physicians and Surgeons, New York NY, USA.
    Lashkariani, Mariam
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Cohort profile: ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden)2019In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 11, p. 101-114Article in journal (Refereed)
    Abstract [en]

    The ESPRESSO study constitutes a novel approach to examine the etiology and prognosis of gastrointestinal disease in which histopathology plays a prominent role. Between 2015 and 2017, all pathology departments (n=28) in Sweden were contacted and asked to procure histopathology record data from the gastrointestinal tract (pharynx to anus), liver, gallbladder, and pancreas. For each individual, local histopathology IT personnel retrieved data on personal identity number, date of histopathology, topography (where the biopsy is taken), morphology (biopsy appearance), and where available free text. In total, between 1965 and 2017, histopathology record data were available in 2.1 million unique individuals, but the number of data entries was 6.1 million because more than one biopsy was performed in many of the study participants. Index individuals with histopathology data were matched with up to five controls from the general population. We also identified all first-degree relatives (parents, children, full siblings), and the index individual's first spouse. The total study population consisted of 13.0 million individuals. Data from all the study participants have been linked to Swedish National Healthcare Registers allowing research not only on such aspects as fetal and perinatal conditions and the risk of future gastrointestinal disease but also on the risk of comorbidity and complications (including cancer and death). Furthermore, the ESPRESSO database allows researchers and practitioners to identify diagnoses and disease phenotypes not currently indexed in national registers (including disease precursors). The ESPRESSO database increases the sensitivity and specificity of already-recorded diseases in the national health registers. This paper is an overview of the ESPRESSO database.

  • 13.
    Ludvigsson, Jonas F.
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, NY, USA.
    Sun, Jiangwei
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Olén, Ola
    Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Sachs' Children and Youth Hospital, Stockholm South General Hospital, Stockholm, Sweden; Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden..
    Song, Mingyang
    Departments of Epidemiology and Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
    Halfvarson, Jonas
    Örebro University, School of Medical Sciences. Department of Gastroenterology.
    Roelstraete, Bjorn
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Khalili, Hamed
    Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA.
    Fang, Fang
    Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Normal Gastrointestinal Mucosa at Biopsy and Overall Mortality: Nationwide Population-Based Cohort Study2022In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 14, p. 889-900Article in journal (Refereed)
    Abstract [en]

    Background: Normal gastrointestinal (GI) mucosa on endoscopy has been linked to a lower risk of colorectal cancer (CRC) but its association to overall death is unknown.

    Methods: We identified 466,987 individuals with a first GI biopsy 1965-2016 with normal mucosa (60.6% upper GI and 39.4% lower GI) through all Swedish pathology departments (n = 28). They were individually matched to 2,321,217 reference individuals without a GI biopsy and also compared to 505,076 full siblings. Flexible parametric models were applied to estimate hazard ratio (HRs) and 95% confidence interval (95% CI) for death.

    Results: During a median follow-up of ~11 years, 85,859 (18.39%) of individuals with normal mucosa and 377,653 (16.27%) of reference individuals died. This corresponded to incidence rates of 147.56/10,000 vs 127.90/10,000 person-years respectively (rate difference: 19.66/10,000 person-years), with the multivariable-adjusted HR of 1.21 (95% CI: 1.20-1.22). Excess mortality was seen for both upper and lower biopsy with normal mucosa. Particularly higher HRs for death were seen in males, individuals biopsied when aged <40 years, those without a prior record of GI disease, and those with high education. Mortality risk was most increased in the first five years after biopsy (HR = 1.34; 95% CI: 1.32-1.36) but decreased thereafter. Having a GI biopsy with normal mucosa was associated with excess mortality from cardiovascular (CVD)disease (HR = 1.02; 95% CI: 1.01-1.03), cancer (HR = 1.58; 95% CI: 1.56-1.61), GI disease (HR = 1.65; 95% CI: 1.58-1.71), and other causes (HR = 1.10; 95% CI: 1.08-1.11). Sibling comparisons yielded similar results.

    Conclusion: Compared with individuals without a GI biopsy, those with a normal GI biopsy due to clinical symptoms had a higher mortality particularly in the first five years after biopsy, and especially from GI disease and cancer.

  • 14.
    Ludvigsson, Jonas F.
    et al.
    Örebro University, School of Medical Sciences. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, United Kingdom; Department of Medicine, Celiac Disease Center, Columbia University College of Physicians and Surgeons, New York, NY, United States.
    van Vollenhoven, Ronald
    Department of Rheumatology, Amsterdam Rheumatology & Immunology Center, Amsterdam, Netherlands.
    Prevalence and comorbidity of relapsing polychondritis2016In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 8, p. 361-362Article in journal (Other academic)
  • 15.
    Lundberg, Frida E.
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden.
    Johansson, Anna L. V.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden.
    Mortality in 43,598 men with infertility - a Swedish nationwide population-based cohort study2019In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 11, p. 645-657Article in journal (Refereed)
    Abstract [en]

    Background: Previous studies indicate a higher risk of comorbidity in men with infertility; however, research on mortality is scarce and the few studies that do exist have rarely differentiated between infertility and infertility-related diagnoses.

    Objective: To examine mortality in men with an infertility or infertility-related diagnosis.

    Design, setting, and participants: Population-based cohort study of men born in 1944-1992 in Sweden. We used Cox regression estimated hazard ratios (HRs) for infertility while adjusting for number of children, education, year of birth, country of birth, diabetes, hypertension, liver disease and end-stage renal disease. In all, 43,598 men with a diagnosis of infertility and 57,733 men with an infertility-related diagnosis were compared with 2,762,254 men (reference group) without such diagnoses.

    Outcome measures: All-cause and cause-specific mortality at age 20 to 69 years.

    Results and limitations: The 2,863,585 men in the study were followed for a median time of 22.0 years. During follow-up, 439 men with a diagnosis of infertility died, corresponding to a crude incidence rate of 1.56 deaths per 1,000 person-years. These figures can be compared with 1,400 deaths in men with an infertility-related diagnosis (1.96 deaths/1,000 person-years) and 99,463 deaths in reference individuals (2.17 deaths/1,000 person-years). Overall, men with a diagnosis of infertility did not have a higher risk of death (adjusted [a] HR=0.98; 95% confidence interval [95% CI]=0.89-1.08), but had a higher risk of death before age 30 (20-29 years) (aHR=3.26; 95% CI=2.42-4.41). This early excess mortality was largely explained by cancer diagnosed before infertility. Having an infertility-related diagnosis was associated with death (aHR=1.23; 95% CI=1.17-1.30). Limitations include the lack of general screening for infertility in Sweden and the lack of information on semen parameters.

    Conclusion: Men with a diagnosis of infertility are not at a higher risk of death than the general population, although having a diagnosis related to infertility may be linked to a higher risk of death.

    Patient summary: Men with a diagnosis of infertility do not seem to have a higher risk of death though an infertility-related diagnosis in men is associated with the risk of death.

  • 16.
    Molero, Yasmina
    et al.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden; Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, UK.
    Zetterqvist, Johan
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Lichtenstein, Paul
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Almqvist, Catarina
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Paediatric Allergy and Pulmonology Unit at Astrid Lindgren Children’s Hospital, Karolinska University Hospital of Paediatrics, Stockholm, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Paediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK; Department of Medicine, Columbia University College of Physicians and Surgeons, New York NY, USA.
    Parental nicotine replacement therapy and offspring bronchitis/bronchiolitis and asthma - a nationwide population-based cohort study2018In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 10, p. 1339-1347Article in journal (Refereed)
    Abstract [en]

    Background: Prior evidence shows that environmental tobacco smoke is a risk factor for respiratory tract infections, wheeze, and asthma. Nicotine replacement therapy has been shown to increase smoking cessation. However, no prior studies have explored if parental use decreases the risk of bronchitis/bronchiolitis and asthma in the offspring.

    Objective: To examine whether nicotine replacement therapy varenicline, given to parents, was associated with a reduction in bronchitis/bronchiolitis and/or asthma in their children.

    Methods: This study is a population-based cohort study, linking data from nationwide registers, and using a within-individual design that minimizes selection effects and controls for time-invariant confounding factors. Participants included 37,420 parents with a collected prescription of varenicline with 72,392 offspring <18 years of age. Exposure was defined as collected prescriptions of varenicline among the parents. Primary outcomes were offspring hospital visits for bronchitis/bronchiolitis (ICD10: J20 or J21) and offspring hospital visits for asthma (ICD10: J45).

    Results: Parental varenicline treatment was associated with a lower rate of visits for bronchitis/bronchiolitis in their children (incidence rate ratio [IRR]=0.67; 95% CI=0.50-0.91), but no association was found for asthma (IRR=1.08; 95% CI=0.97-1.19). The rate reduction of bronchitis/bronchiolitis was similar when we restricted data to children aged 0-3 years (IRR=0.71; 95% CI=0.52-0.97) and to maternal varenicline treatment (IRR=0.64; 95% CI=0.43-0.96). When restricting the outcomes to unplanned visits only (ie, excluding booked appointments, followups, and referrals), no associations were found (IRR=0.72, 95% CI=0.51-1.02).

    Conclusion: In this cohort study, nicotine replacement treatment in parents was associated with reduced hospital visits for bronchitis/bronchiolitis in their children.

  • 17.
    Mouratidou, Natalia
    et al.
    Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden; 2Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Malmborg, Petter
    2Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Sachs’ Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden.
    Järås, Jacob
    2Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Sigurdsson, Vignir
    Department of Pediatrics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg and Queen Silvia’s Children’s Hospital, Gothenburg, Sweden.
    Sandström, Olof
    Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden.
    Fagerberg, Ulrika L.
    6Department of Women ́s and Children ́s Health, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Centre for Clinical Research, Västmanland Hospital, Västerås, Uppsala University, Västerås, Sweden.
    Bröms, Gabriella
    2Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Gastroenterology, Danderyds Hospital, Stockholm, Sweden.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. 9Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden.
    Olén, Ola
    2Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden; Sachs’ Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden.
    Identification of Childhood-Onset Inflammatory Bowel Disease in Swedish Healthcare Registers: A Validation Study2022In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 14, p. 591-600Article in journal (Refereed)
    Abstract [en]

    Purpose: The Swedish National Patient Register (NPR) is often used in observational studies of childhood-onset inflammatory bowel disease (IBD) (<18 years of age) and its subtypes, but the validity of previously used register-based algorithms for capturing childhood-onset IBD has never been examined.

    Methods: We identified a random sample of 233 individuals with at least two first ever diagnostic listings of IBD in the NPR between 2002 and 2014. We calculated the test characteristics for different register-based definitions of IBD and its subtypes using the Copenhagen criteria and the revised Porto criteria as gold standard, both based on medical chart review. We made assumptions of the occurrence of undiagnosed IBD in the general child population based on available literature.

    Results: Out of 233 individuals with at least two diagnostic listings of IBD, 216 had true IBD, resulting in a positive predictive value (PPV) = 93% (95% confidence interval (CI) 89-96), sensitivity = 88% (95% CI 83-92), specificity = 100% (95% CI 100-100), and negative predictive value (NPV) = 100% (95% CI 100-100). The PPV for the NPR-based definitions of IBD subtypes at time of first IBD diagnosis and at end of follow-up were 78% (95% CI 69-86) and 88% (95% CI 80-94), respectively, for Crohn's disease and 74% (95% CI 63-83) and 71% (95% CI 60-80), respectively, for ulcerative colitis.

    Conclusion: The validity of register-based definitions of childhood-onset IBD in the Swedish NPR is high and can be used to identify patients in observational research.

  • 18.
    Sundelin, Heléne E. K.
    et al.
    Department of Pediatrics, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Division of Pediatrics, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
    Stephansson, Olof
    Clinical Epidemiology Unit, Department of Medicine, Solna, Karolinska University Hospital and Institutet, Stockholm, Sweden; Department of epidemiology and biostatistics, School of Public Health, University of California, Berkeley CA, USA.
    Hultman, Christina M.
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Icahn School of Medicine at Mt Sinai, New York NY, USA.
    Ludvigsson, Jonas F.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Pediatrics, Örebro University Hospital, Örebro, Sweden; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK; Department of Medicine, Columbia University College of Physicians and Surgeons, New York NY, USA.
    Pregnancy outcomes in women with autism: a nationwide population-based cohort study2018In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 10, p. 1817-1826Article in journal (Refereed)
    Abstract [en]

    Background: The consequences of autism in pregnancy outcomes have not been explored before, although it is of crucial importance because of the frequent comorbidities and medication in this group of women.

    Objectives: To estimate the risk of adverse pregnancy outcomes in women diagnosed with autism.

    Design: Nationwide population-based cohort study.

    Setting: Sweden.

    Participants: Singleton births identified in the Swedish Medical Birth Registry, 2006-2014. A total of 2,198 births to women diagnosed with autism registered in the Swedish National Patient Registry were compared to 877,742 singleton births to women without such a diagnosis.

    Main outcome and measures: Preterm delivery. Secondary measures were cesarean delivery (emergency and elective), Apgar score <7 at 5 minutes, small for gestational age, large for gestational age, stillbirth, gestational diabetes, and preeclampsia. ORs were calculated through logistic regression, adjusted for maternal age at delivery, maternal country of birth, smoking, maternal body mass index, parity, calendar year of birth, and psychotropic and antiepileptic medication during pregnancy.

    Results: Women with autism were at increased risk of preterm birth (OR=1.30; 95% CI=1.10-1.54), especially medically indicated preterm birth (OR=1.41; 95% CI=1.08-1.82), but not with spontaneous preterm birth. Maternal autism was also associated with an increased risk of elective cesarean delivery (OR=1.44; 95% CI=1.25-1.66) and preeclampsia (OR=1.34; 95% CI=1.08-1.66), but not with emergency cesarean delivery, low Apgar score (<7), large for gestational age, gestational diabetes, and stillbirth. In women with medication during pregnancy, there was no increased risk of adverse pregnancy outcome except for induction of delivery (OR=1.33; 95% CI=1.14-1.55).

    Conclusion and relevance: Maternal autism is associated with preterm birth, likely due to an increased frequency of medically indicated preterm births, but also with other adverse pregnancy outcomes, suggesting a need for extra surveillance during prenatal care.

  • 19. Sundin, Per-Ola
    et al.
    Udumyan, Ruzan
    Örebro University, School of Medical Sciences.
    Fall, Katja
    Örebro University, School of Medical Sciences. Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Montgomery, Scott
    Örebro University, School of Medical Sciences. Clinical Epidemiology Unit, Department of Medicine, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden; Department of Epidemiology and Public Health, University College, London, UK.
    Hospital admission with pneumonia and subsequent persistent risk of chronic kidney disease: national cohort study2018In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 10, p. 971-979Article in journal (Refereed)
    Abstract [en]

    Background: Although acute onset kidney complications associated with severe infections including pneumonia are well characterized, little is known about possible subsequent delayed risk of chronic kidney disease (CKD).

    Patients and methods: Associations between hospital admission with pneumonia in adulthood and raised risks of subsequent CKD were evaluated in a cohort of all male residents in Sweden born from 1952 to 1956 (n=284,198) who attended mandatory military conscription examinations in late adolescence (n=264,951) and were followed up through 2009. CKD and pneumonia were identified using Swedish national registers, and their associations were evaluated using Cox regression. Excluding the first year, the subsequent period was divided into <= 5, > 5-<= 15, and > 15 years after hospital admission with pneumonia. Follow-up ended on the date of first incident diagnosis of kidney disease, death, emigration, or December 31, 2009, whichever occurred first.

    Results: During a median follow-up of 36.7 (interquartile range 35.3-37.9) years from late adolescence, 5,822 men had an inpatient pneumonia diagnosis without contemporaneous kidney disease. Among exposed men, 136 (2.3%) were later diagnosed with CKD compared with 2,749 (1.2%) of the unexposed. The adjusted hazard ratio for CKD in the first year after the first episode of pneumonia was 14.55 (95% confidence interval, 10.41-20.32), identifying early onset kidney complications and possibly pre-existing undiagnosed CKD. Starting follow-up 1 year after pneumonia to reduce the potential influence of surveillance bias and the risk of reverse causation, the adjusted hazard ratio for CKD in the first 5 years of follow-up was 5.20 (95% confidence interval, 3.91-6.93) and then attenuated with increasing time.

    Conclusion: Pneumonia among inpatients is associated with a persistently increased risk for subsequent CKD, with the highest risk during the years immediately after pneumonia. Health care professionals should be aware of this period of heightened risk to facilitate early diagnosis and secondary preventive interventions.

  • 20.
    Zelic, Renata
    et al.
    Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Giunchi, Francesca
    Pathology Department, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
    Fridfeldt, Jonna
    Department of Urology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Carlsson, Jessica
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Urology.
    Davidsson, Sabina
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Urology.
    Lianas, Luca
    Data-Intensive Computing Division, Center for Advanced Studies, Research and Development in Sardinia (CRS4), Pula, Italy.
    Mascia, Cecilia
    Data-Intensive Computing Division, Center for Advanced Studies, Research and Development in Sardinia (CRS4), Pula, Italy.
    Zugna, Daniela
    Cancer Epidemiology Unit, Department of Medical Sciences, University of Turin, and CPO-Piemonte, Turin, Italy.
    Molinaro, Luca
    Division of Pathology, A.O. Città della Salute e della Scienza Hospital, Turin, Italy.
    Vincent, Per Henrik
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Urology, Karolinska University Hospital, Stockholm, Sweden.
    Zanetti, Gianluigi
    Data-Intensive Computing Division, Center for Advanced Studies, Research and Development in Sardinia (CRS4), Pula, Italy.
    Andrén, Ove
    Örebro University, School of Medical Sciences. Department of Urology.
    Richiardi, Lorenzo
    Cancer Epidemiology Unit, Department of Medical Sciences, University of Turin, and CPO-Piemonte, Turin, Italy.
    Akre, Olof
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Urology, Karolinska University Hospital, Stockholm, Sweden.
    Fiorentino, Michelangelo
    Pathology Service, Maggiore Hospital, University of Bologna, Bologna, Italy.
    Pettersson, Andreas
    Clinical Epidemiology Division, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
    Prognostic Utility of the Gleason Grading System Revisions and Histopathological Factors Beyond Gleason Grade.2022In: Clinical Epidemiology, E-ISSN 1179-1349, Vol. 14, p. 59-70Article in journal (Refereed)
    Abstract [en]

    Background: The International Society of Urological Pathology (ISUP) revised the Gleason system in 2005 and 2014. The impact of these changes on prostate cancer (PCa) prognostication remains unclear.

    Objective: To evaluate if the ISUP 2014 Gleason score (GS) predicts PCa death better than the pre-2005 GS, and if additional histopathological information can further improve PCa death prediction.

    Patients and Methods: We conducted a case-control study nested among men in the National Prostate Cancer Register of Sweden diagnosed with non-metastatic PCa 1998-2015. We included 369 men who died from PCa (cases) and 369 men who did not (controls). Two uro-pathologists centrally re-reviewed biopsy ISUP 2014 Gleason grading, poorly formed glands, cribriform pattern, comedonecrosis, perineural invasion, intraductal, ductal and mucinous carcinoma, percentage Gleason 4, inflammation, high-grade prostatic intraepithelial neoplasia (HGPIN) and post-atrophic hyperplasia. Pre-2005 GS was back-transformed using i) information on cribriform pattern and/or poorly formed glands and ii) the diagnostic GS from the registry. Models were developed using Firth logistic regression and compared in terms of discrimination (AUC).

    Results: The ISUP 2014 GS (AUC = 0.808) performed better than the pre-2005 GS when back-transformed using only cribriform pattern (AUC = 0.785) or both cribriform and poorly formed glands (AUC = 0.792), but not when back-transformed using only poorly formed glands (AUC = 0.800). Similarly, the ISUP 2014 GS performed better than the diagnostic GS (AUC = 0.808 vs 0.781). Comedonecrosis (AUC = 0.811), HGPIN (AUC = 0.810) and number of cores with ≥50% cancer (AUC = 0.810) predicted PCa death independently of the ISUP 2014 GS.

    Conclusion: The Gleason Grading revisions have improved PCa death prediction, likely due to classifying cribriform patterns, rather than poorly formed glands, as Gleason 4. Comedonecrosis, HGPIN and number of cores with ≥50% cancer further improve PCa death discrimination slightly.

1 - 20 of 20
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf