Bidirectional associations between daily sleep and pain severity in adults with rheumatoid arthritis: A daily diary and actigraphy study.

Poor sleep and pain are common in rheumatoid arthritis (RA). This study sought to understand the temporal relationships between multidimensional sleep and pain in daily life among individuals with RA. Participants with RA completed up to four waves of 7-day daily diary and sleep actigraphy spanning two years (n=117, Mean age=58.05 years, 87% female). A sleep health composite captured regularity, satisfaction, alertness, timing, efficiency, and duration. Both individual sleep dimensions and the composite were examined. Average daily pain severity, night pain, morning pain, and morning joint stiffness were assessed. Adjusted models controlled for sociodemographic characteristics, depression, anxiety, fatigue, and frequency of pain medication use in linear mixed-effects models. After adjusting for multiple comparisons, at the between-person level, the sleep health composite was not associated with pain or joint stiffness outcomes. Participants with shorter nap duration reported less night pain, and participants with higher sleep efficiency reported less daily pain, night pain, morning pain, and joint stiffness. At the daily level, better sleep health the previous night was associated with less night pain and less morning pain the following day. Nights with better sleep quality, higher sleep efficiency, and longer sleep duration were associated with less pain and joint stiffness the next day. Conversely, less night pain was associated with better sleep health the following night. In sum, night pain shares a bidirectional relationship with the sleep health composite, and notably, sleep quality and efficiency influence pain in daily life. PERSPECTIVE: Among adults with RA, there is bidirectionality between better sleep health and less night pain in daily life. Notably, sleep quality, nap duration, efficiency, and duration are associated with pain in adults with rheumatoid arthritis.