Economic and Health-Related Quality of Life Outcomes of Whiplash Associated Disorders
Pink J., Petrou S., Williamson E., Williams M., Lamb SE.
© Copyright 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Study Design. This study examines the links between severity of whiplash associated disorder and costs and health outcomes. Objective. The study aims to estimate the economic costs and health-state utilities associated with disability levels and recovery trajectories after acute whiplash injury. Summary of Background Data. Data used were from the Managing Injuries of the Neck Trial, which collected information on 3851 people over a 12-month period after acute whiplash injury. Methods. Effects of whiplash associated disorder severity on economic costs (measured from a societal perspective and separately from a health and personal social services perspective) were estimated using two-part regression models, comprising probability of incurring a cost and the total cost, given one was incurred. Effects on health-state utilities (measured using the EQ-5D and SF-6D) were estimated using ordinary least squares regression, and two-part models as for costs. Results. There was a direct relationship between severity of disability after acute whiplash injury and economic costs. Between baseline and 4 months, average societal costs for those with no disability were £99.55 (UK£, 2009 prices), increasing to £668.53 for those with complete disability. Average societal costs for the whole sample were £234.15 over the first 4 months, decreasing to £127.51 between 8 and 12 months. Conversely, utility scores decreased with increased disability. The average EQ-5D utility score was 0.934 at 4 months for those with no disability, decreasing to 0.033 for those with complete disability. The average EQ-5D utility score for the whole sample increased from 0.587 immediately post-injury to 0.817 at 12 months. Relative costs and disutilities generated by the multivariate models are also presented by disability level and recovery trajectory. Conclusion. These results provide estimates of the costs and health-state utilities associated with disability levels and recovery trajectories after acute whiplash injury. They can be used to inform estimates of the cost-effectiveness of interventions targeting whiplash-associated disorders. Level of Evidence: 3