Cost-effectiveness analysis of health tapestry, a complex primary care program for older adults: a post-hoc analysis

We initially reported on the cost-effectiveness of a 6-month randomized controlled implementation trial which evaluated Health TAPESTRY, a primary care program for older adults, at the McMaster Family Health Team (FHT) site and 5 other FHT sites in Ontario, Canada. While there were no statistically significant between-group differences in outcomes at month 6 post randomization, positive outcomes were observed at the McMaster FHT site, which recruited 40% (204/512) of the participants. The objective of this post-hoc study was to determine the cost-effectiveness of Health TAPESTRY based on data from the McMaster FHT site.

Costs included the cost to implement Health TAPESTRY at McMaster as well as healthcare resource consumed, which were costed using publicly available sources. Health-related-quality-of-life was evaluated with the EQ-5L-5L at baseline and at month 6 post randomization. Quality-adjusted-life-years (QALYs) were calculated under an-area-under the curve approach. Unadjusted and adjusted regression analyses (two independent regression analyses on costs and QALYs, seemingly unrelated regression [SUR], net benefit regression) as well as difference-in-difference and propensity score matching (PSM) methods, were used to deal with the non-randomized nature of the trial. Sampling uncertainty inherent to the trial data was estimated using non-parametric bootstrapping. The return on investment (ROI) associated with Health TAPESTRY was calculated. All costs were reported in 2021 Canadian dollars.

With an intervention cost of $293/patient, Health TAPESTRY was the preferred strategy in the unadjusted and adjusted analyses. The results of our bootstrap analyses indicated that Health TAPESTRY was cost-effective compared to usual care at commonly accepted WTP thresholds. For example, if decision makers were willing to pay $50,000 per QALY gained, the probability of Health TAPESTRY to be cost effective compared to usual care varied from 0.72 (unadjusted analysis) to 0.96 (SUR) when using a WTP of $50,000/QALY gained. The DID and ROI analyses indicated that Health Tapestry generated a positive ROI.

Health TAPESTRY was the preferred strategy when implemented at the McMaster FHT. We caution care in interpreting the results because of the post-hoc nature of the analyses and limited sample size based on one site.