Purpose: In order to assess whether different databases generate information which can be reliable compared with each other, this study aimed to assess to which degree prescribing rates for systemic antibiotics from a nationwide electronic general practitioner (GP) database correspond with national reimbursement rates, and to investigate for which indications antibiotics are prescribed.
Methods: Nationwide GP prescribing data were collected from the Second Dutch National Survey of General Practice (DNSGP-2) based on 90 general practices serving 358 008 patients in 2001. Dutch national reimbursement rates for GPs were derived from claims data of the Dutch Drug Information System/Health Care Insurance Board (GIP/CVZ) from 2001. We calculated antibiotic prescribing rates per 1000 patients/inhabitants for each database, and these rates were compared for the total rates and according to antibiotic subgroups. Indications for which GPs prescribed antibiotics were described.
Results: In national reimbursement data, 339 antibiotic prescriptions per 1000 inhabitants were prescribed by GPs, while the nationwide GP database showed 255 prescriptions per 1000 patients (75% coverage with reimbursement rates). The nationwide GP database showed high volumes of sulphonamides & trimethoprim, and small volumes of macrolides and quinolones. Half of the prescriptions (48%) were prescribed for respiratory diseases, a quarter (26%) for urinary diseases and 7% for ear diseases.
Conclusions: GPs voluntarily participating in a research network prescribe less antibiotics than Dutch GPs in general, and are cautious in prescribing newer and more broad-spectrum antibiotics. This point has to be taken into account when databases will be compared with each other.