Do trauma systems work? A comparison of major trauma outcomes between Aberdeen Royal Infirmary and Massachusetts General Hospital.

Trauma is an important matter of public health and a major cause of mortality. Since the late 1980s trauma care provision in the United Kingdom is lacking when compared to the USA. This has been attributed to a lack of organisation of trauma care leading to the formation of trauma networks and Major Trauma Centres in England and Wales. The need for similar centres in Scotland is argued currently. We assessed the activity of two quite different trauma systems by obtaining access to comparative data from two hospitals, one in the USA and the other in Scotland. Aggregate data on 5604 patients at Aberdeen Royal Infirmary (ARI) from 1993 to 2002 was obtained from the Scottish Trauma Audit Group. A comparable data set of 16,178 patients from Massachusetts General Hospital (MGH). Direct comparison of patient demographics; injury type, mechanism and Injury Severity Score (ISS); mode of arrival; length of stay and mortality were made. Statistical analysis was carried out using Chi-squared and Cochran-Mantel-Haenszel. There were significant differences in the data sets. There was a higher proportion of penetrating injuries at MGH, (8.6% vs 2.6%) and more severely injured patients at MGH, patients with an ISS>16 accounted for nearly 22.1% of MGH patients compared to 14.0% at ARI. ISS 8-15 made up 54.6% of ARI trauma with 29.6% at MGH. Falls accounted for 50.1% at ARI and 37.9% at MGH. Despite the higher proportion of severe injuries at MGH and crude mortality rates showing no difference (4.9% ARI vs 5.2% MGH), pooled odds ratio of mortality was 1.4 (95% confidence interval 1.2-1.6) showing worse mortality outcomes at ARI compared to MGH. In conclusion, there were some differences in case mix between both data sets making direct comparison of the outcomes difficult, but the effect of consolidating major trauma on the proportion and number of severely injured patients treated in the American Level 1 centre was clear with a significant improvement in mortality in all injury severity groups.