To Örebro University

IMPORTANCE: Little is known about the risk of suicidal behavior in relation to having a spouse with a cancer diagnosis.

OBJECTIVE: To estimate the risk of suicide attempt and suicide death among spouses of patients with cancer.

DESIGN, SETTING, AND PARTICIPANTS: This nationwide cohort study in Denmark collected registry-based data from 1986 through 2016. Analyses were performed from August 8, 2022, to October 30, 2023. Individuals who had a spouse with a cancer diagnosed during 1986 to 2015 were compared with individuals whose spouse did not have a cancer diagnosis during the same period, randomly selected from the general population and matched by birth year and sex.

EXPOSURE: Having a spouse with a cancer diagnosis.

MAIN OUTCOMES AND MEASURES: Suicide attempt was identified through the Danish National Patient Register and the Danish Psychiatric Central Research Register, whereas suicide death was identified through the Danish Causes of Death Register, through 2016. Flexible parametric and Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs for suicide attempt and suicide death among spouses of patients with a cancer diagnosis.

RESULTS: The study included 409 338 exposed individuals and 2 046 682 unexposed individuals (median [IQR] age at cohort entry for both groups, 63 [54-70] years; 55.4% women). During the follow-up, 2714 incident cases of suicide attempt among exposed individuals (incidence rate [IR], 62.6 per 100 000 person-years) and 9994 among unexposed individuals (IR, 50.5 per 100 000 person-years) were identified, as well as 711 cases of suicide death among the exposed individuals (IR, 16.3 per 100 000 person-years) and 2270 among the unexposed individuals (IR, 11.4 per 100 000 person-years). An increased risk of suicide attempt (HR, 1.28; 95% CI, 1.23-1.34) and suicide death (HR, 1.47; 95% CI, 1.35-1.60) was observed among spouses of patients with cancer throughout the follow-up. The increased risk was particularly notable during the first year after the cancer diagnosis, with an HR of 1.45 (95% CI, 1.27-1.66) for suicide attempt and 2.56 (95% CI, 2.03-3.22) for suicide death. There was a greater risk increase for both suicide attempt and suicide death when the cancer was diagnosed at an advanced stage or when the spouse died after the cancer diagnosis.

CONCLUSIONS AND RELEVANCE: These findings suggest a need for clinical and societal awareness to prevent suicidal behaviors among spouses of patients with cancer, particularly during the first year following the cancer diagnosis.