Cost-effectiveness of telephone cognitive behavioral therapy for osteoarthritis-related insomnia

Abstract

Background: Osteoarthritis-related insomnia is the most common form of comorbid insomnia among older Americans. A randomized clinical trial found that six sessions of telephone-delivered cognitive behavioral therapy for insomnia (CBT-I) improved sleep outcomes in this population. Using these data, we evaluated the incremental cost-effectiveness of CBT-I from a healthcare sector perspective.

Methods: The study was based on 325 community-dwelling older adults with insomnia and osteoarthritis pain enrolled with Kaiser Permanente of Washington State. We measured quality-adjusted life years (QALYs) using the EuroQol 5-dimension scale. Arthritis-specific quality of life was measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Insomnia-specific quality of life was measured using the Insomnia Severity Index (ISI) and nights without clinical insomnia (i.e., "insomnia-free nights"). Total healthcare costs included intervention and healthcare utilization costs.

Results: Over the 12 months after randomization, CBT-I improved ISI and WOMAC by -2.6 points (95% CI: -2.9 to -2.4) and -2.6 points (95% CI: -3.4 to -1.8), respectively. The ISI improvement translated into 89 additional insomnia-free nights (95% CI: 79 to 98) over the 12 months. CBT-I did not significantly reduce total healthcare costs (-$1072 [95% CI: -$1968 to $92]). Improvements in condition-specific measures were not reflected in QALYs gained (-0.01 [95% CI: -0.01 to 0.01]); at a willingness-to-pay of $150,000 per QALY, CBT-I resulted in a positive net monetary benefit of $369 with substantial uncertainty (95% CI: -$1737 to $2270).

Conclusion: CBT-I improved sleep and arthritis function without increasing costs. These findings support the consideration of telephone CBT-I for treating insomnia among older adults with comorbid OA. Our findings also suggest potential limitations of the general quality of life measures in assessing interventions designed to improve sleep and arthritis outcomes.

Keywords: cognitive behavioral therapy; cost-effectiveness analysis; insomnia; osteoarthritis; sleep initiation and maintenance disorders.

FIGURE 1

Incremental cost-effectiveness planes of cognitive behavioral therapy for insomnia (CBT-I) compared with education-only control (EOC) with 95% confidence ellipse. The point estimate is red and each of the 1000 bootstrap replicates are black. Panel A. Effectiveness measured by quality-adjusted life years (QALYs). The point estimate is in the South West quadrant, meaning CBT-I produces fewer QALYs (−0.005) and reduces costs (−$1072) Panel B. Effectiveness measured by Insomnia Severity Index (ISI). The point estimate is South East quadrant, meaning CBT-I reduces insomnia (−2.6 ISI) and costs (−$1072) Panel C. Effectiveness measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The point estimate is in the South East quadrant, meaning CBT-I reduces arthritis-related functional limitations (−2.6 WOMAC) and reduces costs (−$1072) Panel D. Effectiveness measured by insomnia-free nights (i.e., nights without clinical insomnia). The point estimate is South East quadrant, meaning CBT-I increases insomnia-free nights (88.6 nights) and reduces costs (−$1072)