To Örebro University

PURPOSE: The aim of this study was to examine the association of comorbid heart disease, defined as chronic heart failure or ischemic heart disease, on all-cause and cause-specific hospitalization and mortality in patients with COPD over a period of nearly 15 years.

MATERIALS AND METHODS: The cohort study included patients with COPD from primary and secondary care in 2005 with data from questionnaires and medical record reviews. The Swedish Board of Health and Welfare provided hospitalization and mortality data from 2005 through 2019. Cox regression analyses, adjusted for sex, age, educational level, smoking status, BMI, exacerbations, dyspnea score and comorbid diabetes or hypertension, assessed the association of comorbid heart disease with all-cause and cause-specific time to first hospitalization and death. Linear regression analyses, adjusted for the same variables, assessed this association with hospitalization days per year for those patients that had been hospitalized.

RESULTS: Of the 1071 patients, 262 (25%) had heart disease at baseline. Cox regression analysis showed a higher risk of hospitalization for patients with heart disease for all-cause (HR (95% CI) 1.55; 1.32-1.82), cardiovascular (2.14; 1.70-2.70) and other causes (1.27; 1.06-1.52). Patients with heart disease also had an increased risk of all-cause (1.77; 1.48-2.12), cardiovascular (3.40; 2.41-4.78) and other (1.50; 1.09-2.06) mortality. Heart disease was significantly associated with more hospitalization days per year of all-cause (regression coefficient 0.37; 95% CI 0.15-0.59), cardiovascular (0.57; 0.27-0.86) and other (0.37; 0.12-0.62) causes. No significant associations were found between heart disease and respiratory causes of hospitalization and death.

CONCLUSION: Comorbid heart disease in patients with COPD is associated with an increased risk for all-cause hospitalization and mortality, mainly due to an increase of hospitalization and death of cardiovascular and other causes, but not because of respiratory disease. This finding advocates the need of a strong clinical focus on primary and secondary prevention of cardiovascular disease in patients with COPD.

Spirometry should be used to confirm a diagnosis of chronic obstructive pulmonary disease (COPD). This test is not always performed, leading to possible misdiagnosis. We investigated whether the proportion of patients with diagnostic spirometry has increased over time as well as factors associated with omitted or incorrectly interpreted spirometry. Data from medical reviews and a questionnaire from primary and secondary care patients with a doctors' diagnosis of COPD between 2004 and 2010 were collected. Data were compared with a COPD cohort diagnosed between 2000 and 2003. Among 703 patients with a first diagnosis of COPD between 2004 and 2010, 88% had a diagnostic spirometry, compared with 59% (p < 0.001) in the previous cohort. Factors associated with not having diagnostic spirometry were current smoking (OR 2.21; 95% CI 1.36-3.60), low educational level (OR 1.81; 1.09-3.02) and management in primary care (OR 2.28; 1.02-5.14). The correct interpretation of spirometry results increased (75% vs 82%; p = 0.010). Among patients with a repeated spirometry, 94% had a persistent FEV1/FVC or FEV1/VC ratio <0.70.

Purpose: A multidimensional approach in the risk assessment of chronic obstructive pulmonary disease (COPD) is preferable. The aim of this study is to compare the prognostic ability for mortality by different COPD assessment systems; spirometric staging, classification by GOLD 2011, GOLD 2017, the age, dyspnea, obstruction (ADO) and the dyspnea, obstruction, smoking, exacerbation (DOSE) indices.

Patients and Methods: A total of 490 patients diagnosed with COPD were recruited from primary and secondary care in central Sweden in 2005. The cohort was followed until 2017. Data for categorization using the different assessment systems were obtained through questionnaire data from 2005 and medical record reviews between 2000 and 2003. Kaplan-Meier survival analyses and Cox proportional hazard models were used to assess mortality risk. Receiver operating characteristic curves estimated areas under the curve (AUC) to evaluate each assessment systems´ ability to predict mortality.

Results: By the end of follow-up, 49% of the patients were deceased. The mortality rate was higher for patients categorized as stage 3-4, GOLD D in both GOLD classifications and those with a DOSE score above 4 and ADO score above 8. The ADO index was most accurate for predicting mortality, AUC 0.79 (95% CI 0.75-0.83) for all-cause mortality and 0.80 (95% CI 0.75-0.85) for respiratory mortality. The AUC values for stages 1-4, GOLD 2011, GOLD 2017 and DOSE index were 0.73, 0.66, 0.63 and 0.69, respectively, for all-cause mortality.

Conclusion: All of the risk assessment systems predict mortality. The ADO index was in this study the best predictor and could be a helpful tool in COPD risk assessment.