Measures of sleep are not routinely captured in trials assessing treatment outcomes in knee osteoarthritis - A scoping systematic review and call to action

OBJECTIVE: To identify and map the extent to which trials for pain interventions in individuals with knee osteoarthritis (OA) track measures of sleep, characterize the type of sleep measure assessed, and assess their influence on pain-related effect sizes. DESIGN: A scoping review was conducted, searching seven bibliometric databases from 2000 to 2022. We included all randomized controlled trials with a primary purpose of assessing non-surgical pain management interventions for adults with knee OA. All non-surgical interventions and any comparator or control were included. Demographic data were pooled from all trials. RESULTS: 926 trials conducted in 61 countries met eligibility. Nineteen trials (2.1%) recorded some form of sleep assessment. Eleven trials (1.2%) assessed a formal index of sleep disturbance collected at multiple time points. No trials formally assessed the influence of sleep on the primary pain outcome (e.g., as a potential mediator), nor met the most recent guidelines for core data element recommendations regarding sleep assessment. CONCLUSION: This review highlights the paucity of sleep data captured and reported in randomized controlled trials for knee OA. The vast majority of trials addressing symptomatic knee OA do not capture sleep measures, significantly limiting the ability to accurately determine an intervention's effect on pain. Future research should include formal sleep-centric assessments measured at multiple time points to analyze sleep dysfunction and its relationship on treatment effects.