Linking prescription and patient-identifying data: a pilot study.

OBJECTIVE: To link a Pharmaceutical Benefits Scheme (PBS) prescription data set with patient-identifying data held by the Health Insurance Commission (HIC) and to then determine the prevalence of prescribing of cardiovascular drugs, non-steroidal anti-inflammatory drugs, hypnotics and minor tranquillizers, and diuretics (prescribed without other cardiovascular drugs) by age and sex in two defined populations.

DESIGN: Prescription data for a three-month period in 1985 were matched with patient-identifying information to obtain a database which included the patient's age, sex and an identifying number, for each prescription record. The percentages of the population taking a drug from each of the drug categories mentioned above were then determined and the effect of age, sex and region of residence on prescribing prevalence was investigated using logistic regression analysis.

SETTING: Two rural regions of Australia with a total population of 65,087 residents.

MEASUREMENTS AND MAIN RESULTS: Of the 101,383 prescriptions dispensed over the period 96% could be matched with HIC information. In the two regions combined, the percentages of the population taking a cardiovascular drug, non-steroidal anti-inflammatory drug, hypnotic or minor tranquilizer, or diuretic (without other cardiovascular drugs) were 10.4%, 5.8%, 3.5% and 2.5%, respectively. Prescribing rates were higher for females than males, increased with age and varied between the two regions. Approximately 5% of women aged 30-39 years were taking diuretics without other cardiovascular drugs, compared with only 0.2% of men in the same age group.

CONCLUSIONS: This pilot study illustrates the use of a patient-identified prescription database for drug utilisation review, therapeutic audit and hypothesis generation.