Electronic Merger of Large Health Care Data Sets: Cautionary Notes From a Study of Agricultural Morbidity in New York State

Abstract

ABSTRACT Agriculture ranks among industries with the highest rates of occupational injury and fatality. Administrative medical data sets have long been thought to have potential for occupational injury surveillance. This research explores the feasibility of establishing an agricultural injury surveillance system in New York State that combines data from existing electronic sources. Prehospital Care Report (PCR) data containing the nature of the accident, type of injury, time and date, and patient disposition were received. Researchers also obtained both hospital inpatient and emergency department (ED) records for 2007 through 2009 from the Statewide Planning and Research Cooperative System (SPARCS). For SPARCS data, a computer algorithm identified all potential cases of agricultural injury using International Classification of Diseases (ICD)-9 codes. An attempt was then made to match PCR and SPARCS data using accident date, gender, age, and admitting hospital. Of the PCR records that were matched to SPARCS, 46.8% were found on subsequent inspection to not actually relate to the same incident. Total PCR counts for 2007 and 2008 showed considerable fluctuation, at 2,512,828 and 2,948,841, respectively. A total of 1275, 1336, and 1393 farm injuries were identified in the SPARCS records for 2007, 2008, and 2009, respectively. This study demonstrates that accurate matching of PCR and SPARCS records requires the use of unique personal identifiers. Further, annual fluctuations in PCR counts preclude their current use in a surveillance system. An electronic data set consisting of SPARCS data could be used for surveillance, but would benefit from the addition of PCR data as these become more consistent.