Suicide risk within one year of cognitive impairment diagnosis in older adults: a nationwide retrospective cohort study
Abstract Background This study aims to investigate suicide risk within one year of receiving a diagnosis of cognitive impairment in older adults without mental disorders. Methods This study used National Health Insurance Service-Senior Cohort data on older adults with newly diagnosed cognitive impairment including Alzheimer’s disease, vascular dementia, other/unspecified dementia, and mild cognitive impairment from 2004 to 2012. We selected 41,195 older adults without cognitive impairment through 1:1 propensity score matching using age, gender, Charlson Comorbidity Index, and index year, with follow-up throughout 2013. We eliminated subjects with mental disorders and estimated adjusted hazard ratios (AHR) of suicide deaths within one year after diagnosis using the Cox proportional hazards models. Results We identified 49 suicide deaths during the first year after cognitive impairment diagnosis. The proportion of observed suicide deaths was the highest within one year after cognitive impairment diagnosis (48.5% of total); older adults with cognitive impairment were at a higher suicide risk than those without cognitive impairment (AHR, 1.89; 95% confidence interval [CI], 1.18–3.04). Subjects with Alzheimer’s disease and other/unspecified dementia were at greater suicide risk than those without cognitive impairment (AHR, 1.94, 1.94; 95% CI, 1.12–3.38, 1.05–3.58). Suicide risk in female and young-old adults (60–74 years) with cognitive impairment was higher than in the comparison group (AHR, 2.61, 5.13; 95% CI, 1.29–5.28, 1.48–17.82). Conclusions Older patients with cognitive impairment were at increased suicide risk within one year of diagnosis. Early intervention for suicide prevention should be provided to older adults with cognitive impairment.