The potential of using billing data for emergency department injury surveillance

To determine the availability of and sample statewide ED injury information obtained from hospital billing data for the purpose of demonstrating the feasibility of information acquisition for subsequent data linkage.

A retrospective, database investigation was conducted to obtain data describing a statewide stratified sample of ED patients. The aim was to collect a computerized billing summary record for each injured ED patient seen at each sampled hospital over a 1-year period. All 215 Pennsylvania acute care hospitals in 1991 were eligible for sample selection. Data collection for the project was conducted in 1993. Participants included directors of hospital medical records and billing departments.

Twenty-four hospitals contributed data sets from the original target goal of 31 strata. The final combined data set contained 187,404 records with injury diagnoses from approximately 616,000 ED patient visits, representing a 12% sample of all annual statewide ED visits. Age, sex, date of visit, and primary diagnosis fields were completed from the retrieved data > 99% of the time. More than two-thirds of the sampled records had a social security number, and total charges were recorded > 90% of the time. Other variables such as name and address were contained in < 50% of the records submitted. E-codes were usually not available.

Retrospective compilation of multihospital ED billing data to create a statewide ED data sample-with the potential for injury research and probabilistic database linkage-can be accomplished; there are, however, important limitations.