Obese motorcycle riders have a different injury pattern and longer hospital length of stay than the normal-weight patients

Background: The adverse effects of obesity on the physical health have been extensively studied in the general population, but not in motorcycle riders (includes both drivers and pillions). The aim of this study was to compare injury patterns, injury severities, mortality rates, and in-hospital or intensive care unit (ICU) length of stay (LOS) between obese and normal-weight patients who were hospitalized for the treatment of trauma following motorcycle accidents in a level I trauma center.

Methods: Detailed data of 466 obese adult patients with a body mass index (BMI) ≥30 kg/m(2) and 2701 normal-weight patients (25 > BMI ≥18.5 kg/m(2)) who had sustained motorcycle accident-related injuries were retrieved from the Trauma Registry System between January 1, 2009 and December 31, 2013. We used the Pearson's chi-squared test, Fisher's exact test, and independent Student's t-test to analyze differences between the two groups.

Results: Compared to normal-weight motorcycle riders, more obese riders were men and drivers as opposed to pillions. In addition, fewer obese motorcycle riders showed alcohol intoxication. Analyses of the patients' Abbreviated Injury Scale (AIS) scores revealed that obese motorcycle riders presented with a higher rate of injury to the thorax, but a lower rate of injury to the face than normal-weight patients. In addition, obese motorcycle riders had a 2.7-fold greater incidence of humeral, 1.9-fold greater incidence of pelvic, and 1.5-fold greater incidence of rib fractures. In contrast, normal-weight motorcycle riders sustained a significantly higher rate of maxillary and clavicle fractures. Obese motorcycle riders had a significant longer in-hospital LOS than normal-weight motorcycle riders did (10.6 days vs. 9.5 days, respectively; p = 0.044), with an increase in in-hospital LOS of 0.82 days associated with every 10-unit increase in BMI. No statistically significant differences in Injury Severity Score (ISS), New Injury Severity Score (NISS), Trauma-Injury Severity Score (TRISS), mortality, percentage of patients admitted to the ICU, or LOS in the ICU were found between obese and normal-weight patients.

Discussion: No differences of injury severity, mortality, and LOS in the ICU between obese and normal-weight motorcycle riders in this study may be partly attributed to the motorcycle injuries occur at relatively low velocity, considering that the riding of majority of motorcycles are forbidden on highways in Taiwan and that most traffic accidents occur in relatively crowded streets.

Conclusion: Obese motorcycle riders had different injury characteristics and bodily injury patterns than normal-weight motorcycle riders. Moreover, they had a longer in-hospital LOS; this was particularly true for those with pelvic fractures. However, injury severity and mortality were not significantly different between the two groups.