General practice variation when initiating long-term prescribing of proton pump inhibitors: a nationwide cohort study

Background: Suggestions of overprescribing of proton pump inhibitors (PPIs) for long-term treatment in primary care have been raised. This study aims to analyse associations between general practice characteristics and initiating long-term treatment with PPIs. Methods: A nationwide register-based cohort study of patients over 18 years redeeming first-time prescription for PPI issued by a general practitioner in Denmark in 2011. Patients redeeming more than 60 defined daily doses (DDDs) of PPI within six months were defined first-time long-term users. Detailed information on diagnoses, concomitant drug use and sociodemography of the cohort was extracted. Practice characteristics such as age and gender of the general practitioner (GP), number of GPs, number of patients per GP, geographical location and training practice status were linked to each PPI user. Logistic regression analysis was used to determine associations between practice characteristics and initiating long-term prescribing of PPIs. Results: We identified 90 556 first-time users of PPI. A total of 30 963 (34.2 %) met criteria for long-term use at six months follow-up. GPs over 65 years had significantly higher odds of long-term prescribing (OR 1.32, CI 1.16-1.50), when compared to younger GPs (< 45 years). Furthermore, female GPs were significantly less likely to prescribe long-term treatment with PPIs (OR 0.87, CI 0.81-0.93) compared to male GPs. Conclusions: Practice characteristics such as GP age and gender could explain some of the observed variation in prescribing patterns for PPIs. This variation may indicate a potential for enhancing rational prescribing of PPIs.