Incidence of self-harm and its subsequent clinical management and unnatural-cause mortality risk among older adults: a primary-care based cohort study.

Problem

Much attention has focussed on self-harming behaviour in younger individuals with little known about non-fatal self-harm in older aged adults. Evidence from secondary care settings indicate people who self-harm at older age more often have higher suicidal intent and therefore at increased risk of dying as a consequence than individuals who harm themselves at younger age. In a novel primary care cohort of older aged adults who have harmed themselves, we aimed to estimate the incidence of self-harm and the subsequent clinical management and unnatural-cause mortality risk following self-harm.

Approach

The Clinical Practice Research Datalink (CPRD) is an anonymised primary care electronic health record database with linkage to national hospitalisation and mortality records. We identified 4,124 adults 65 years and older, with an index self-harm episode recorded during 2001-2014 and we estimated standardised annual incidence of self-harm over this period. Clinical management during the 12 months following the index self-harm episode was assessed as the proportion receiving a referral to mental health services and the frequency of psychotropic prescribing. We matched older adults with a self-harm episode with up to 20 unaffected adults of the same age, gender and registered general practice, and estimated cause-specific mortality risks, including suicide.

Findings

Annual self-harm incidence rates were comparable between males and females (4.2 vs. 4.0 per 10,000 person years, respectively) with stable rates observed over the 13-year study period. Incidence increased with age; 31% higher among 75-84 and 76% higher among 85+ year olds, compared to ages 65-74. Following self-harm, 11.7% (n=335) of adults were referred to mental health services, with more females than males referred (13.1% vs. 9.7%, χ2=7.8, p=0.005). Overall, 59.3% (n=1,692) of older adults were prescribed an antidepressant of which 19.9% (n=336) received a tricyclic antidepressant. Adults who had self-harmed died from unnatural causes (mostly suicides and accidents) an estimated 19 times more frequently than the matched comparison cohort during the first 12 months of follow-up and 3 times more frequently in subsequent years. We observed markedly elevated risks for suicide (≤12 months of follow-up: hazard ratio 131.3, 95% CI 51. 5, 335.0; >12 months: hazard ratio 145.43, 95% CI 53.9, 392.3).

Consequences

This large population-based study provides a unique primary care focus on self-harm among older adults. We have highlighted important implications for clinical management, with a high frequency of tricyclic antidepressant prescribing known to be potentially fatally toxic in overdose and where NICE guidelines clearly recommend their avoidance in this circumstance. The elevated risk of unnatural death within the first year following self-harm, further emphasises the need for earlier intervention, careful prescribing and increased support when older individuals consult following an episode of self-harm or with other health conditions.