Sources of Drug Utilization Data

Data Sources

Different types of drug use information are required depending on the problem being examined.

Data are collected, or are available, at national, regional and local health facility or household level and may be derived from quantitative or qualitative studies.
Examples are as follows:

- Sales data. Sales data may be obtained from drug importers, wholesalers or local manufacturers at national, regional or local levels.

- Dispensing data either comprehensive or sampled. Computerised pharmacies can easily collect data on drugs dispensed. Alternatively, sample data can be collected manually. Reimbursement systems, which operate in a number of countries at the national level provide comprehensive dispensing data down to the individual prescription level, as all prescriptions are submitted and recorded for reimbursement. This is generally called “claims” data. Similar data are often available through health insurance or health maintenance organizations.

These databases can sometimes allow collection of demographic information on the patients, and information on dose, duration of treatment and co-prescribing.

- Patient encounter-based data. This is usually collected by specially designed sampling studies such as those carried out by market research organizations. However, increasing use of information technology at the medical practice level will make such data available more widely in the near future. These methods have the advantage of potentially providing accurate information on Prescribed Daily Doses, patient demographics, duration of therapy, co-prescribing, indications, morbidity and co-morbidity, and sometimes outcomes.

- Patient survey data. Collection of data at the patient level can provide information about actual drug consumption taking into account compliance in filling prescriptions and taking medications as prescribed.

- Health Facility data. Data on medication use at all the above levels is often available in healthcare settings such as hospitals and health centres at regional, district, or village level.

More information is also available in the WHO publication "How to investigate drug use in health facilities: selected drug use indicators  ".