THE USE OF PRESCRIPTION CLAIMS DATABASES IN PHARMACOEPIDEMIOLOGIC RESEARCH - THE ACCURACY AND COMPREHENSIVENESS OF THE PRESCRIPTION CLAIMS DATABASE IN QUEBEC

Despite the potential benefits of using prescription claims databases for pharmacoepidemiological research, little work has been reported on the nature of available information or its accuracy. The purpose of t his study was to describe information contained within the prescriptio n claims database in Quebec, and to assess the accuracy of drug inform ation that might be used to monitor drug exposure and physician prescr ibing. The comprehensiveness of the prescriptions claims database was assessed by examining 1,917,214 records of dispensed prescriptions for a regionally stratified random sample of 65,349 Quebec elderly in 199 0. We found that values in key fields (individual identifiers, drug, q uantity, date dispensed and duration) were missing or out of range in 0-0.4% of records. The accuracy of data were examined in 723 prescript ions filled by 306 elderly patients attending one internal medicine cl inic. Of these prescriptions, 83% were filled by the patient and corre ctly identified the patient and drug and in 89% of these 599 records, the prescribing physician was correctly identified. The quantity and d uration of the prescriptions were accurate in 69.1% and 72.1% of recor ds, respectively. We conclude that the prescription claims database in Quebec may represent one of the most accurate means of determining dr ugs dispensed to individuals. There may be limitations in using this d atabase for dosing information.