O021 Associations between signs of insomnia and incident joint replacement

Abstract Insomnia frequently co-exists with hip or knee osteoarthritis (OA). However, there is a paucity of evidence on the relationship between insomnia and undergoing joint replacement. This study examines the longitudinal association between insomnia and incidence of hip or knee joint replacement in adults with OA. Data were from participants with knee (n = 81 958) or hip pain (n = 41 737) in the past 3 months from the UK Biobank. Using self-reported baseline data, participants were classified as (1) “never”, (2) “sometimes”, or (3) “usually” experiencing signs of insomnia (i.e., trouble falling asleep or waking up in the middle of the night). We examined the association between baseline signs of insomnia and incident total joint replacement for the hip or knee using Cox proportional hazards models, adjusted for confounders. From enrolment to 250 weeks, reporting “usual” signs of insomnia was associated with undergoing a knee replacement (HR 1.14, 95% CI 1.04 to 1.26) in those with knee pain. No association was observed between “usually” experiencing signs of insomnia and knee replacement beyond 250 weeks (HR 0.99, 95% CI 0.93 to 1.06), nor between “sometimes” experiencing signs of insomnia and incident knee replacement. For those with hip pain, “usually” or “sometimes” experiencing signs of insomnia was not associated with incident hip replacement. In this large longitudinal cohort, “usual” signs of insomnia were associated with undergoing a knee joint replacement within the first 250 weeks, but not after, and not with hip replacement. These findings highlight the potential value of addressing sleep problems when managing knee pain.