Objective: No large population-based prospective study has investigated the risks of suicide and death by other externally caused injuries (ECIs) among stroke patients. The purpose of this study was to examine whether stroke increases the risks of suicide and ECI deaths.
Methods: We analyzed data from the Japan Public Health Center–based Prospective Study between 1990 and 2010. Poisson regression models were used to calculate adjusted risk ratios (RR) for suicide and ECI deaths. To adjust for unmeasured confounders, case-crossover analyses of all stroke patients who died by suicide and ECIs were also performed.
Results: A population-based cohort of 93,027 Japanese residents was established. During the follow-up period, 4793 residents had been diagnosed as having stroke. During this period, there were 22 suicides and 53 ECI deaths among stroke patients and 490 suicides and 675 ECI deaths among those who were stroke-free. Stroke patients were at increased risk for death by suicide and ECIs within the first 5 years after a stroke (suicide: RR = 10.2, 95% confidence interval [CI] = 6.3–16.6; ECI: RR = 12.8, 95% confidence interval = 9.0–18.2). Furthermore, case-crossover analyses confirmed the results of the Poisson regression models.
Conclusions: The RRs of suicide and ECI deaths within the first 5 years after a stroke were noticeably high. These findings underscore the need for clinicians and health care professionals to be aware of causes of death after a stroke and closely monitor patients during the first few poststroke years.
From the Center for Suicide Prevention, National Institute of Mental Health (T.Y.), and Department of Epidemiology and Biostatistics, Translational Medical Center (N.Y.), National Center of Neurology and Psychiatry, Tokyo, Japan; Department of Neuropsychiatry (M. Inagaki), Okayama University Hospital, Okayama, Japan; Epidemiology and Prevention Division (M. Iwasaki, M. Inoue, S.T.), Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; Department of Psychiatry and Cognitive-Behavioral Medicine (T.A.), Nagoya City University Graduate School of Medical Sciences, Aichi, Japan; and Public Health Graduate School of Medicine (H.I.), Osaka University, Osaka, Japan.
Address correspondence to Masatoshi Inagaki, MD, PhD, Department of Neuropsychiatry, Okayama University Hospital, Shikata-cho, Kita-ku, Okayama 700-8558, Japan. E-mail: firstname.lastname@example.org
Address for reprints: Shoichiro Tsugane, MD, PhD, Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. E-mail: email@example.com
Received for publication November 11, 2014; revision received May 2, 2014.