Alternative approaches to derive disability weights in injuries: do they make a difference?

Abstract

Background In burden of disease studies, several approaches are used to assess disability weights, a scaling factor necessary to compute years lived with disability (YLD). The aim of this study was to quantify disability weights for injury consequences with two competing approaches, (a) standard QALY/DALY model (SQM) which derives disability weights from patient survey data and (b) the annual profile model (APM) which derives weights for the same patient data valued by a panel. Methods Disability weights were assessed using (a) EQ-5D data from a postal survey among 8,564 injury patients 2, 5, and 9 months after attending the Emergency Department, and (b) preferences of 143 laymen elicited with the time trade-off method. Results Compared with APM, SQM disability weights were consistently higher. YLD calculated with SQM disability weights was more than three times higher compared with YLD calculated with APM disability weights, for mild injuries with short duration, this increase was six fold. Conclusions The APM seems the preferred method in burden of injury studies that includes mild conditions with a rapid course, since the SQM approach might overestimate the impact of the latter. The APM, however, might underestimate the impact of injury consequences, especially in case of severe injuries.

Beyond the neglect of psychological consequences: post-traumatic stress disorder increases the non-fatal burden of injury by more than 50%

“…Several burden-of-injury studies used disability weights that were assessed with generic health status measures such as the EQ-5D 2 31 32. These measures allow patients to describe their health state by choosing a functional level for each generic health domain.…”

Improved and standardized method for assessing years lived with disability after injury

“…23 Increasingly, researchers believe that the best disability weights to use for estimating the burdens of injury are those derived from empirical follow-up data on the health-related quality of life of individual trauma patients. [24][25][26] In at least two studies, disability weights have been generated in this manner, with the …”

“…injuries of low severity) that the patients may have experienced. 24 In the present study, therefore, the empirically-derived disability weights for 15 injury groups (e.g. concussion, eye injury, and fracture of facial bones) were supplemented with disability weights, from a different study, that were derived in such a way that the restrictions to measure the effects of any short-lived consequences of injury (i.e.…”

“…This assumption, that health remains constant for relatively long periods of time, is untenable for injuries with very short duration and low severity. We therefore used panel-derived disability weights for some conditions 24 in the development of the new method. This conservative approach may have resulted in underestimates of the burdens associated with these conditions (Appendix A).…”

Validating and Improving Injury Burden Estimates Study: the Injury-VIBES study protocol

“…The DALY is a summary measure of population health which combines years of life lost (YLL) and years lived with disability (YLD) 1 3 8. The YLL component uses incident mortality data.…”