Measuring and assessing risk of quality of life loss following a road traffic injury: A proposed methodology for use of a composite score.

INTRODUCTION: Assessments of the impact of road traffic injuries (RTIs) on quality of life (QoL) can benefit from the use of combined characteristics of the injurious event.

AIM: The burden of having sustained a RTI was computed using a composite score that comprised three elements (i.e. number of injuries sustained in the crash, body parts affected, and severity of the injuries) that relate to the probability of subsequent long-term QoL lost by individuals 1-4 years after the crash.

METHODOLOGY: The QoL of injured victims aged 11-90 years that crashed in Sweden between 2007 and 2009 was compared with that of a random sample of non-injured individuals frequency-matched by sex and age. Injury information to build the composite score was obtained from a national register that contains data on the number of injuries, their severity, and the body parts affected. The QoL was assessed in 2010 for both injured and non-injured individuals using the standardized Euro Quality of Life questionnaire. Logistic regression was used to investigate whether the composite score was predictive of low QoL (<90% of the mean of non-injured referents) adjusting for sex, age, and time elapsed since the injury occurrence. The composite score was grouped into five exposure categories (0.01-1, 1.01-1.5, 1.51-2, 2.01-3 and 3.01-9 units).

RESULTS: Compared with the non-injured reference group, all exposure categories showed statistically significant increased adjusted ORs for low QoL ranging from 2.35 (95% CI 1.48-3.72) in the 0.01-1.00 lowest injury category to 6.10 (95% CI 3.65-10.2) in the highest 3.01-9.00 with a slightly decreasing plateau in the intermediate categories (point ORs between 3.86 and 3.06). Yet, all 95% CIs across the exposure categories overlapped.

CONCLUSION: Long-term reduction in QoL is a burden experienced by the victims of mild to severe RTCs. The proposed composite score can be an initial step in the development of more elaborated instruments that can be useful in policy making and regulation.