Components of sleep quality and sleep fragmentation in rheumatoid arthritis and osteoarthritis

Poor sleep is increasingly recognized as contributing to a decreased quality of life, increased morbidity/mortality and heightened pain perception. The purpose of the present study was to assess components of sleep quality and self-identified contributors to sleep fragmentation in rheumatoid arthritis (RA) and osteoarthritis (OA) patient populations.

Consecutive RA and OA clinic patients were invited to participate in a self-administered questionnaire study which included the validated multi-domain Pittsburgh Sleep Quality Index (PSQI), visual analogue scales for pain, fatigue, global functioning, modified Health Assessment Questionnaire (mHAQ), stress scores, the Centre for Epidemiologic Studies-Depression (CES-D) score, the 36-item short form (SF-36) quality of life measure, the Rheumatoid Arthritis Disease Activity Index (RADAI), the Epworth Sleepiness Scale (ESS), Berlin score for obstructive sleep apnoea (OSA) risk and the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria.

The study population included 145 RA and 78 OA patients. PSQI global scores were >5 in 62% of RA and 67% of OA patients. Multivariate analysis identified global functioning and the CES-D to be independent predictors for higher global PSQI scores in RA patients, whereas in OA patients predictors were the mHAQ and SF-36 mental component summary. Abnormalities in subjective sleep assessment, sleep latency, sleep duration, sleep efficiency, daytime dysfunction and increased sleep-aid medication use were observed in both populations. The most common abnormality reported by both RA and OA patients was increased sleep fragmentation. The most frequent self-identified cause for sleep disturbance was 'need to use the washroom' by 51% of RA and 49% of OA patients, and, second most common, 'pain' was identified as a cause for awakening by 33% of RA and 45% of OA patients.

A high prevalence of abnormal sleep quality in both RA and OA patient populations was observed. The most common abnormality was sleep fragmentation, with an increased sleep disturbance score. 'Need to use the washroom' and 'pain' were the most common self-identified reasons for awakening from sleep. A review of sleep hygiene, optimization of urological status, and rheumatological disease symptomatic control may prove beneficial in terms of sleep health.