Developing a statewide emergency medical services database linked to hospital outcomes: a feasibility study

Statewide emergency medical services (EMS) data linked to outcomes are critical for promoting high-quality emergency care; however, many states do not have such a resource.

To demonstrate the feasibility of creating such a statewide database using a one-month pilot sample.

This was a prospective cohort study of all EMS patient encounters throughout Oregon during May 2008. Eighty-three National EMS Information System (NEMSIS) variables were obtained from EMS agencies via electronic or paper charts. We reformatted raw data, mapped NEMSIS fields, entered hard-copy records, and uploaded data files to a statewide electronic medical records platform. Records from transport and nontransport (first-responder) agencies caring for the same patients were matched using probabilistic linkage, then linked to three statewide outcome databases (Oregon Hospital Discharge Database [OHDD], Oregon Trauma Registry [OTR], and Oregon Department of Transportation [ODOT] Crash File) using similar methodology. We estimated population-adjusted case ascertainment by county and used descriptive statistics to characterize the process.

During the one-month period, we collected 27,474 EMS records in 36 (100%) counties from 106 (77%) licensed transport agencies and 10 nontransport agencies, representing 20,673 persons. There were 3,302 admission record matches, 285 trauma registry matches, and 392 crash record matches. Overall, 3,979 hospital outcomes were matched to EMS records for 80 (75%) transport and six (60%) first-responder agencies. Median per-agency match rates were 16.3% for OHDD (interquartile range [IQR] 8.3-22.2%, range 0-56.5%), 0.9% for OTR (IQR 0-2.5%, range 0-60.0%), and 1.6% for ODOT (IQR 0-3.5%, range 0-23.1%).

Developing a statewide EMS database linked to hospital outcomes is feasible. The processes used in this study and match rate estimates may provide a template for other states to follow, enhancing opportunities for outcomes-based EMS research and EMS quality assurance efforts.