Rheumatic Conditions as Risk Factors for Self-Harm: A Retrospective Cohort Study

Abstract

Objective To examine the risk of self-harm in rheumatological conditions Methods Retrospective cohort study using data from the Clinical Practice Research Datalink. Patients with ankylosing spondylitis, fibromyalgia, osteoarthritis or rheumatoid arthritis were identified between 1990–2016 and matched to patients without these conditions. Incident self-harm was defined by medical record codes following a rheumatological diagnosis. Incidence rates (per 10,000 person-years(PY)) were reported for each condition, both overall and year-on-year(2000-2016). Cox regression analysis determined risk (hazard ratios(HR), 95% confidence interval(CI)) of self-harm for each rheumatological cohort compared to the matched unexposed cohort. Initial crude analysis was subsequently adjusted and stratified by age and gender. Due to non-proportionality over time, osteoarthritis was also stratified by disease duration(<1 year, =1-<5 years, =5-<10 years, =10 years). Results Incidence of self-harm was highest in patients with fibromyalgia (25.12 (95%CI 22.45,28.11) per 10,000 PY) and lowest for osteoarthritis (6.48 (6.20, 6.76)). There was a crude association with each rheumatological condition and self-harm, except for ankylosing spondylitis. Though attenuated, these associations remained after adjustment for fibromyalgia (HR 2.06(95%CI 1.60,2.65)), rheumatoid arthritis (1.59(1.20,2.11)) and osteoarthritis (1-<5years: 1.12 (1.01,1.24); =5-<10 years: 1.35 (1.18,1.54)). Age and gender were weak effect modifiers for these associations. Conclusions Primary care patients with fibromyalgia, osteoarthritis or rheumatoid arthritis (but not ankylosing spondylitis) are at increased risk of self-harm compared to people without these rheumatological conditions. Clinicians need to be aware of the potential for self-harm in patients with rheumatological conditions (particularly fibromyalgia), explore mood and risk with them, and offer appropriate support and management.