Limitations of Secondary Data Sets for Road Traffic Injury Epidemiology:

Abstract

Objectives. To evaluate the completeness of descriptive information andaccuracy of ambulance data when compared with two other secondary sources of data, namely, medical examiners' reports andmedical records, in the city of Karachi, Pakistan. Methods. A retrospective chart review was carried out of all road traffic injury (RTI) victims transported by an ambulance service in Karachi from January 1 to December 31, 2003. Information on the name, age, andgender of the victim, date, time, andplace of injury, andtype of injury andits outcome was obtained, andthen compared with medical examiners' data andinpatient medical records. The variables missing in the ambulance service database were identified. Results. The ambulance service transported 1,245 RTI patients during 2003, 81% of whom were taken to one of three trauma centers. Twenty percent died before reaching hospital. There were missing variables in 340 (27%) cases, the majority of which were the unique identifiers such as name andage (67%). Data on other variables were reported in 95% or more cases. None of the medical examiners' reports or inpatient medical records contained a description of event of injury. The agreement rate for the variables available in the three data sets ranged from 61% to 100%. Conclusion. Secondary data on injuries, such as ambulance reports, medical examiners' reports, andmedical records, have significant limitations. In Karachi, except with regard to unique identifiers, ambulance data seem to provide information just as accurate as that in medical examiners' andinpatient medical records.