Antibiotics in Dutch general practice: nationwide electronic GP database and national reimbursement rates

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.

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.

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.

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.