GPs' antibiotic prescription patterns for respiratory tract infections--still room for improvement.

Objective: Inappropriate use of antibiotics is associated with increased antibiotic resistance in the community. About 90% of all antibiotic prescriptions in Norway are issued by general practitioners and in 60% issued for respiratory tract infections. The article describes and analyses antibiotic prescription patterns by general practitioners in Vestfold, Norway.
Design: Prospective cohort study.
Subjects: A total of 145 list-holding general practitioners in Vestfold, Norway in February to March 2003.
Methods: Merging of two electronic administrative data sets: antibiotic prescriptions dispensed in pharmacies and general practitioners' electronic bills from the National Insurance Agency.
Main Outcome Measures: Proportion and type of antibiotic prescribed for different respiratory tract infectious diagnoses.
Results: We found large variations among general practitioners' antibiotic prescription habits. In 27% of consultations with RTI diagnoses, an antibiotic was prescribed; 37% were for Penicillin V and 28% for a macrolide. Quinolones and cephalosporins were only rarely prescribed. In a logistic regression analysis the following factors were independently associated with antibiotic prescription rate: type of infection, type of contact, being a general practitioner specialist, and years since medical exam. In another logistic regression analysis the following factors were independently associated with broad-spectrum antibiotic prescription: type of infection, age of patient, type of contact, being a specialist, length of list, and being a high prescriber of antibiotics.
Conclusion: The variation in proportion of total antibiotic prescribing and broad-spectrum prescription for respiratory tract infections is high, and reveals potentials to change general practitioners' prescription behaviour, in order to maintain the positive situation in Norway as to antibiotic resistance.