Prevalence of inappropriate prescribing in primary care

Objective: To describe the prevalence of inappropriate prescribing in primary care in Copenhagen County, according to the Medication Appropriateness Index (MAI) and to identify the therapeutic areas most commonly involved. Setting: A cross-sectional study was conducted among 212 elderly (> 65 years) polypharmacy patients (five or more different medications) listed to 41 general practitioners (GPs) in the County of Copenhagen. Method: Patients exposed to polypharmacy were identified via the database recording the drug subsidy system of Danish pharmacies. For each patient, data were collected on subsidised medications prescribed over 3 months by the patients' own GPs. The GPs were asked to provide baseline information regarding the patients' medical history and detailed information regarding the subsidised and non-subsidised medications prescribed to the patients. A MAI was scored for medication prescribed to the patients. Topical, dermatological medications and medications not used regularly were excluded. Results: 212 patients were prescribed 1621 medications by their GPs at baseline. In all, 640 (39.5%) of the medications had one or more inappropriate ratings in the 10 criteria making up the MAI. The main part of the patients (94.3%) had one or more inappropriate ratings among their medications. A total of 12.3% of the medications were rated as 'not indicated', 6% were rated as 'ineffective', 6.7% were given in an incorrect dose, 0.7% were prescribed with incorrect directions, 1.3% had impractical directions, 0.7% of the drugs had clinically significant drug-drug interactions, 8.6% had clinically significant drug-disease/condition interactions, 3.1% were unnecessary duplications, 16.5% were given in an unacceptable duration and 27.1% of the medications were not the least expensive alternative. The therapeutic groups most commonly involved in inappropriate prescribing were medications for treatment of peptic ulcer, cardiovascular medications, anti-inflammatory medications, antidepressants, hypnotics and anti-asthmatics. Conclusion: The overall prescribing quality in primary care in Copenhagen County, Denmark is good. However, the majority of patients used one or more medications with inappropriate ratings. The inappropriate prescribing relates to specific therapeutic groups and criteria, which should be targeted in future interventions.