Long-term follow-up of trauma patients before and after implementation of a physician-staffed helicopter: A prospective observational study

INTRODUCTION: The first Danish Helicopter Emergency Medical Service (HEMS) was introduced May 1st 2010. The implementation was associated with lower 30-day mortality in severely injured patients. The aim of this study was to assess the long-term effects of HEMS on labour market affiliation and mortality of trauma patients.

METHODS: Prospective, observational study with a maximum follow-up time of 4.5 years. Trauma patients from a 5-month period prior to the implementation of HEMS (pre-HEMS) were compared with patients from the first 12 months after implementation (post-HEMS). All analyses were adjusted for sex, age and Injury Severity Score.

RESULTS: Of the total 1994 patients, 1790 were eligible for mortality analyses and 1172 (n=297 pre-HEMS and n=875 post-HEMS) for labour market analyses. Incidence rates of involuntary early retirement or death were 2.40 per 100 person-years pre-HEMS and 2.00 post-HEMS; corresponding to a hazard ratio (HR) of 0.72 (95% confidence interval (CI) 0.44-1.17; p=0.18). The HR of involuntary early retirement was 0.79 (95% CI 0.44-1.43; p=0.43). The prevalence of reduced work ability after three years were 21.4% vs. 17.7%, odds ratio (OR)=0.78 (CI 0.53-1.14; p=0.20). The proportions of patients on social transfer payments at least half the time during the three-year period were 30.5% vs. 23.4%, OR=0.68 (CI 0.49-0.96; p=0.03). HR for mortality was 0.92 (CI 0.62-1.35; p=0.66).

CONCLUSIONS: The implementation of HEMS was associated with a significant reduction in time on social transfer payments. No significant differences were found in involuntary early retirement rate, long-term mortality, or work ability.