Predictive factors of nonfatal self-harm among community-dwelling older adults assessed for support services

Older adults receiving support services are a population at risk for self-harm due to physical illness and functional impairment, which are known risk factors. This study aims to investigate the relative importance of predictive factors of nonfatal self-harm among older adults assessed for support services in New Zealand.

interRAI-Home Care (HC) national data of older adults (aged ≥ 60) were linked to mortality and hospital discharge data between January 1, 2012 and December 31, 2016. We calculated the crude incidence of self-harm per 100,000 person-years, and gender and age-adjusted standardized incidence ratios (SIRs). The Fine and Gray competing risk regression model was fitted to estimate the hazard ratio (HR; 95% CIs) of self-harm associated with various demographic, psychosocial, clinical factors, and summary scales.

A total of 93,501 older adults were included. At the end of the follow-up period, 251 (0.27%) people had at least one episode of nonfatal self-harm and 36,333 (38.86%) people died. The overall incidence of nonfatal self-harm was 160.39 (95% CI, 141.36-181.06) per 100,000 person-years and SIR was 5.12 (95% CI, 4.51-5.78), with the highest incidence in the first year of follow-up. Depression diagnosis (HR, 3.02, 2.26-4.03), at-risk alcohol use (2.38, 1.30-4.35), and bipolar disorder (2.18, 1.25-3.80) were the most significant risk factors. Protective effects were found with cancer (0.57, 0.36-0.89) and severe level of functional impairment measured by Activities of Daily Living (ADL) Hierarchy Scale (0.56, 0.35-0.89).

Psychiatric factors are the most significant predictors for nonfatal self-harm among older adults receiving support services. Our results can be used to inform healthcare professionals for timely identification of people at high risk of self-harm and the development of more efficient and targeted prevention strategies, with specific attention to individuals with depression or depressive symptoms, particularly in the first year of follow-up.