gms | German Medical Science

Context: Claims data of German statutory health insurance companies have been used increasingly over the last years for various research purposes. However, little is known about the validity of these data.

Aim of the study: Aim of this study was to analyse whether information relevant for research purposes is accurately recorded in computerized out-patient medication claims data.

Material and method: Data of the Gmünder ErsatzKasse (GEK) were used. Data on the scanned original prescription (gold standard) were validated against that information in computerized claims data. Two studies were done. First, a random sample of 1,000 prescriptions in 2005 was drawn and both the date of writing by the physician and that of drug dispensing by the pharmacy were abstracted from the scanned original prescription. Secondly, a random sample of 300 prescriptions was drawn for each year from 2000 to 2006. Dates of writing and dispensing as well as physician and pharmacy identifiers were evaluated respectively.

Results: Over the years 2000-2006, an increasing proportion of dates of writing was recorded accurately (77.3% to 93.0%; p for trend <0.0001). Dates of dispensing were barely correct until 2003. Thereafter, the agreement ranged from 65.3% in 2004 to 86.1% in 2006 (p for trend <0.0001). We found significant differences in data quality between pharmacy data processing centres (Apothekenrechenzentren). The accuracy of physician (97.7% to 99.7%) and pharmacy identifiers (96.0% to 100.0%) was high and nearly constant over these seven years.

Conclusion: The accuracy of variables analysed in this study is very good for those which are immediately related to the flow of money in German out-patient medication claims data. Dates of prescription and dispensing are of fair quality.