Abstract
OBJECTIVE: To evaluate the cost-utility and cost-effectiveness of the dr. Bart app compared to usual care in people with osteoarthritis (OA) of the knees and hips, applying a health care payer perspective. METHODS: This economic evaluation was conducted alongside a 6-month randomized controlled trial that included 427 participants. The dr. Bart app is a stand-alone eHealth application that invites users to select pre-formulated goals (i.e., "tiny habits") and triggers for a healthier lifestyle. Self-reported outcome measures were health care costs, quality-adjusted life years (QALYs) according to the EuroQol 5-dimension 3-level (EQ-5D-3L) descriptive system, the EuroQol visual analog scale (QALY VAS), patient activation measure 13 (PAM-13), and 5 subscales of the Knee Injury and Osteoarthritis Outcome Score/Hip Disability and Osteoarthritis Outcome Score. Missing data were multiply imputed, and bootstrapping was used to estimate statistical uncertainty. RESULTS: The mean ± SD age of the study participants was 62.1 ± 7.3 years, and the majority of participants were female (72%). Health care costs were lower in the intervention group compared to the group who received usual care (€-22 [95% confidence interval €-36, -3]). For QALY and QALY VAS, the probability of the dr. Bart app being cost-effective compared to usual care was 0.71 and 0.67, respectively, at a willingness-to-pay (WTP) of €10,000 and 0.64 and 0.56, respectively, at a WTP of €80.000. For self-management behavior, symptoms, pain, and activities of daily living, the probability that the dr. Bart app was cost-effective was >0.82, and the probability that the dr. Bart app was cost-effective in the areas of activities and quality of life was <0.40, regardless of WTP thresholds. CONCLUSION: This economic evaluation showed that costs were lower for the dr. Bart app group compared to the group who received usual care. Given the noninvasive nature of the intervention and the moderate probability of it being cost-effective for the majority of outcomes, the dr. Bart app has the potential to serve as a tool to provide education and goal setting in OA and its treatment options.