Trauma is the leading cause of death among persons below 60 years of age. It is a well-established belief that optimal treatment in the early phase after trauma has a major impact on mortality, and the implementation of specific educational programs for trauma care have been a widely adopted strategy aimed at improving the outcome. This strategy has high face validity, but the underlying evidence is poor. The Prehospital Trauma Life Support (PHTLS) program was introduced in 1983 aiming to integrate prehospital trauma care with the Advanced Trauma Life Support (ATLS) program. Approximately half a million prehospital caregivers in over 50 countries have taken the PHTLS course. It has been recognized as one of the leading educational programs for prehospital emergency trauma care. However, the scientific support for improved patient outcome from courses such as PHTLS and ATLS is limited. According to a Cochrane analysis published 2010 there is no evidence to recommend advanced life-support (ALS) training for ambulance crews. Another Cochrane analysis concerning ATLS gave similar results and a recent study indicated even worsened outcome after the implementation of ATLS. An observational study in the county of Uppsala indicated reduced mortality after the implementation of PHTLS but the estimate was uncertain due to a low overall mortality. The aim of this study is to further investigate the association between PHTLS training of ambulance crew members and the outcome in trauma patients in a larger study population. To accomplish this the investigators will use an epidemiological semi-individual design applied to all victims of traffic injury that occurred during the implementation period of the PHTLS course in Sweden (1998-2004). Four outcomes and subsets of patients will be analyzed: Mortality before hospital admission, mortality within 30 days, time to death among survivors to hospital admission and return to work among survivors to hospital discharge.

Source Population: Sweden is divided in 21 administrative regions providing health care (counties). In 2004 Sweden had a population of about 9 million inhabitants with an average population density of 20 inhabitants/km2.

The Emergency Medical Service (EMS)-System: The ambulance staff in Sweden consists of registered nurses and emergency medical technician (EMT) equivalents (nursing assistants with special ambulance training).

Statistics: Hierarchical random effects models will be used to model the binary outcomes. Cox proportional hazards models to analyze the time to event outcomes. The difference in mean predicted outcome between the PHTLS group and the non-PHTLS group will be used to estimate the absolute risk reduction.

Inclusion Criteria:

• Primary incident hospital admissions due to traffic accidents or
• Death due to traffic accidents

Exclusion Criteria:

• If a patient appears more than once, all but the first event will be excluded from the dataset.

Study Population: Motor vehicle traffic crashes were selected using the causes of injury matrix developed by the National Center for Health Statistics, Centers for Disease Control and Prevention, USA.