Using Patient-Reported Outcomes for Economic Evaluation: Getting the Timing Right.

Area of Science:

• Orthopedic Surgery
• Health Economics
• Biostatistics

Background:

• Patient-reported outcome measures (PROMs) are increasingly vital in orthopedic surgery for economic evaluations.
• Generic quality-of-life instruments like the SF-12 are used to estimate quality-adjusted life-years (QALYs).
• The optimal timing for postoperative PROM collection remains debated, potentially impacting economic analyses.

Purpose of the Study:

• To investigate the impact of different postoperative PROM collection timings on QALY estimation bias.
• To determine the optimal time point for postoperative PROM collection in total knee arthroplasty (TKA) for accurate economic evaluation.

Main Methods:

• Compared QALY estimation accuracy using SF-12 data collected at 6 weeks, 3 months, 6 months, and 12 months post-TKA.
• Utilized 5-year follow-up data from the St. Vincent's Melbourne Arthroplasty Outcomes (SMART) registry (n=484).
• Analyzed data under various interpolation methods between measurement points.

Main Results:

• Postoperative PROM collection at 6 weeks, 6 months, or 12 months resulted in significant QALY estimation bias (-41%, 18%, -8% respectively).
• Collecting PROMs at 3 months postoperatively minimized bias, showing only a 6% error.
• Confidence intervals indicated the statistical significance of the observed biases.

Conclusions:

• The timing of PROM collection and interpolation methods critically influence economic evaluation bias in TKA.
• A postoperative PROM measurement at 3 months, with linear interpolation, is recommended for TKA economic evaluations.
• Future economic evaluations should carefully consider the timing and interpolation assumptions for PROM data.