Frequency of comorbid insomnia, pain, and depression in older adults with osteoarthritis: Predictors of enrollment in a randomized treatment trial

Objective: This paper examines the prevalence and severity of comorbid pain, insomnia, and depression in a population sample of older adults with osteoarthritis (OA), and assesses characteristics distinguishing participants from non-participants in a randomized clinical trial to improve pain and sleep. Methods: Potential subjects were Group Health Cooperative members, aged 60+, who had an electronic medical record OA diagnosis in the prior 3 years. Participants were recruited using a low-cost mailed survey. Fifty-five percent of surveys were completed and returned (n = 3321). Persons with Grade II-IV arthritis pain on the Graded Chronic Pain Scale and reporting sleep difficulties 3+ nights/week during the past month with daytime dysfunction (n = 834) were invited to participate in one of three group-format behavioral self-management interventions. A total of 367 participants attended the first group class. Results: One-third (36.4%) of survey respondents had clinically elevated levels of OA pain and insomnia. Group participants and non-participants did not differ in ratings of pain severity, sleep disturbance, depression, or receipt of prescription medications for pain or sleep. Participants were significantly older (p<.001) and more likely to be retired (p<.001) than subjects who were eligible to participate but did not. Conclusion: Participation in a group-format behavioral intervention for pain and insomnia was not related to participant clinical characteristics, but only to factors associated with ability to attend a daytime class (age and retirement status). We conclude that population-based recruitment yielded randomized trial participants who are clinically generalizable to the population of OA patients with significant pain and insomnia. (C) 2011 Elsevier Inc. All rights reserved.