Economic evaluation of a rehabilitation program integrating exercise, self-management, and active coping strategies for chronic knee pain

Objective. To conduct an economic evaluation of the Enabling Self-Management and Coping with Arthritic Knee Pain through Exercise (ESCAPE-knee pain) program. Methods. Alongside a clinical trial, we estimated the costs of usual primary care and participation in ESCAPE-knee pain delivered to individuals (Indiv-rehab) or groups of 8 participants (Grp-rehab). Information on resource use and informal care received was collected during face-to-face interviews. Cost-effectiveness and cost-utility were assessed from between-group differences in costs, function (primary clinical outcome), and quality-adjusted life years (QALYs). Cost-effectiveness acceptability curves were constructed to represent uncertainty around cost-effectiveness. Results. Rehabilitation (regardless of whether Indiv-rehab or Grp-rehab) cost 224 pound (95% confidence interval [95% CI] 184 pound, 262) pound more per person than usual primary care. The probability of rehabilitation being more cost-effective than usual primary care was 90% if decision makers were willing to pay 1,900 pound for improvements in functioning. Indiv-rehab cost 314 pound/person and Grp-rehab 125 pound/person. Indiv-rehab cost 189 pound (95% CI 168 pound, 208) pound more per person than Grp-rehab. The probability of Indiv-rehab being more cost-effective than Grp-rehab increased as willingness to pay (WTP) increased, reaching 50% probability at WTP 5,500 pound. The lack of differences in QALYs across the arms led to lower probabilities of cost-effectiveness based on this outcome. Conclusion. Provision of ESCAPE-knee pain had small cost implications, but it was more likely to be cost-effective in improving function than usual primary care. Group rehabilitation reduces costs without compromising clinical effectiveness, increasing probability of cost-effectiveness.