The risk of suicidal behavior may be increased among the spouses of patients with cancer, according to a retrospective Danish population-based cohort study reported by Liu et al in JAMA Oncology. Clinical and societal awareness was thus deemed essential, particularly during the first year after diagnosis, when the likelihood of such acts appeared to be the highest in this vulnerable population.
“Previous studies have documented elevated levels of psychological distress and an increased risk of psychiatric disorders among the spouses of patients with cancer,” the investigators commented. “To our knowledge, this nationwide cohort study is the first to show [that this population has] an elevated risk of both suicide attempts and suicide deaths.”
Study Details
Using both the Danish Cancer Registry and Danish Civil Registration System, the investigators identified individuals who had a spouse with a cancer diagnosed between 1986 and 2015 (n = 409,338), as well as a birth year– and sex-matched population of those who did not (n = 2,046,682). The Danish National Patient Register and Danish Psychiatric Central Research Register provided data on suicide attempts, and the Danish Causes of Death Register was used to track suicide deaths. The median age at cohort entry was 63 years (range = 54–70 years) for the entire population. More than half (55.4%) of the identified individuals were female.
Both individuals with and without a spouse with cancer were followed until one of the following events was reported: first-onset suicide attempt; suicide death; death from other causes; emigration; or December 31, 2016. The investigators used flexible parametric and Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals for suicidal behaviors—namely, suicide attempts and suicide deaths.
Risk of Suicidal Behavior
A total of 2,714 (incidence rate [IR] = 62.6 per 100,000 person-years) and 9,994 (IR = 50.5 per 100,000 person-years) incident cases of suicide attempts were identified among individuals with and without a spouse with cancer, respectively, during the follow-up period; there were 711 (IR = 16.3 per 100,000 person-years) and 2,270 (IR = 11.4 per 100,000 person-years) documented cases of suicide death in these groups. An increased risk of suicide attempts (hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.23–1.34) and suicide deaths (HR = 1.47, 95% CI = 1.35–1.60) was reported among the spouses of patients with cancer throughout the follow-up period. According to the investigators, it was particularly notable within the first year after the diagnosis of cancer; the hazard ratios for suicide attempts and suicide deaths were 1.45 (95% CI = 1.27–1.66) and 2.56 (95% CI = 2.03–3.22), respectively. There seemed to be a greater risk increase in suicidal behavior both when the cancer was diagnosed at an advanced stage and when the spouse died after the diagnosis.
The investigators concluded: “The risk [of suicide attempts and suicide deaths] was found to be particularly high during the first year after the spouse’s cancer diagnosis and persisted through the entire 30-year follow-up. Additionally, the risk increase in suicidal behavior was greater in individuals with a spouse with cancer diagnosed at advanced stages and after the patient died. Moreover, the risk increase was greater among individuals with a lower level of household income and among those without a common child with the patient with cancer.”
Qianwei Liu, MD, PhD, of Southern Medical University, Guangzhou, China, is the corresponding author of the JAMA Oncology article.
Disclosure: The study was funded by the Swedish Cancer Society, Novo Nordisk Foundation, Independent Research Fund Denmark, Nordic Cancer Union, and the Karen Elise Jensens Fond. For full disclosures of the study authors, visit jamanetwork.com.
