Potentially inappropriate medication prescribing for elderly outpatients in Emilia Romagna, Italy - A population-based cohort study

Background: In the US, a growing body of epidemiological studies has documented widespread potentially inappropriate medication prescribing among the elderly in outpatient settings. However, only limited information exists in Europe. Objective: To evaluate the prevalence of potentially inappropriate medication prescribing among elderly outpatients in Emilia Romagna, Italy and to investigate factors associated with potentially inappropriate medication prescribing in that setting. Methods: Retrospective cohort study using the Emilia Romagna outpatient prescription claims database from I January 2001 to 31 December 2001 linked with information (age, sex and other variables) available from a demographic file of approximately I million Emilia Romagna residents aged >= 65 years. The cohort comprised 849 425 elderly patients who had at least one drug prescription during the study period. The prevalence of potentially inappropriate medication prescribing, as defined by the 2002 Beers' criteria, was measured together with predictors associated with potentially inappropriate medication prescribing. Results: A total of 152 641 (18%) elderly Emilia Romagna outpatients had one or more occurrences of potentially inappropriate medication prescribing. Of these, 11.5% received prescriptions for two medications of concern and 1.7% for three or more. Doxazosin (prescribed to 23% of subjects) was the most frequently occurring potentially inappropriate prescribed medication, followed by ketorolac (20.5%), ticlopidine (18.3%) and amiodarone (12.6%). Factors associated with greater likelihood of potentially inappropriate medication prescribing were older age, overall number of drugs prescribed and greater number of chronic conditions. The odds of receiving potentially inappropriate prescribed medications were lower for females, subjects living in more urban areas and subjects with a higher income level. Conclusions: This study provides strong evidence that potentially inappropriate medication prescribing for elderly outpatients is a substantial problem in Emilia Romagna. Focusing on the prevalence of potentially inappropriate medication prescribing and associated predictors can help in the development of educational programmes targeting outpatient practitioners to influence prescribing behaviour and, therefore, reduce potentially inappropriate medication prescribing.