Method: We conducted an economic evaluation alongside the University Health Network Whiplash Intervention Trial. The trial compared the effectiveness of three interventions for grade I-II acute whiplash injury: 1) the province of Ontario’s legislated standard of care multidisciplinary rehabilitation program (Standard), 2) a recommended evidence-based minimal care intervention consisting of education and activation (Education Activation), and 3) a rehabilitation program designed to reduce administrative burden associated with the standard of care (Rehabilitation). The evaluation was conducted from the payer’s perspective over the trial’s 12-month time-horizon. Costs were extracted from administrative claims files and standardized to 2012 Canadian dollars. Outcomes were measured in quality-adjusted life years (QALYs). Rating scale scores estimated participants’ quality-of-life during the 12-month follow-up and converted into within-trial estimates of participant-level QALYs. Cost-effectiveness was expressed with incremental cost-effectiveness ratios using conventional thresholds. Uncertainty was represented with cost-effectiveness acceptability curves. Sensitivity analyses tested effect of missing data approaches and alternative outcomes (cost per additional claim closed, cost per additional day recovered).
Result: Baseline characteristics were evenly distributed except expectation of recovery and Physical Component Scale scores, therefore analyses were adjusted for these characteristics. Mean costs (95% CI) for each intervention were: Standard (n=101) $5,347 ($3,757, $6,936), Education Activation (n=92) $6,602 ($4,323, $8,882), and Rehabilitation (n=102) $7,626 ($5,481, $9,770). Mean QALYs (95% CI) were: Standard 0.775 (0.753, 0.796), Education Activation 0.750 (0.731, 0.769), and Rehabilitation 0.752 (0.731, 0.773). Differences in costs and effectiveness were not clinically or statistically significant. Standard dominated (less expensive, more effective) all other interventions; this trend was also observed in sensitivity analyses. Within all interventions there was enormous variation in participant-level health services use and frequency of provider visits far exceeding published guidelines.
Conclusion: The legislated standard of care for acute whiplash injury in Ontario is cost-effective compared to education and activation, and a rehabilitation program meant to streamline the administrative process, but differences in cost and outcomes are small. Recommended, evidence-based interventions designed to address increasing health service use and declining outcomes associated with acute whiplash are unlikely to achieve their objective unless legislative environment and possible provider-induced overtreatment issues are addressed.