Potentially inappropriate drug prescription in the elderly in France: a population-based study from the French National Insurance Healthcare system.

BACKGROUND

Inappropriate prescribing is a known risk factor for adverse drug event occurrence in the elderly. In various countries, several studies have used insurance healthcare databases to estimate the national prevalence of potentially inappropriate medications (PIM) in the elderly, as defined by explicit PIM lists. Recently, a representative sample of the French National Insurance Healthcare database, known as the "Echantillon Généraliste des Bénéficiaires" (EGB), was created, making it possible to assess the quality of drug prescription in France. Our objective was to evaluate the prevalence and the regional distribution of PIM prescription in the elderly aged 75 years and over in France, using the French PIM list and the EGB database.

METHODS

The list of drugs reimbursed to patients aged 75 years and over from 1 March 2007 to 29 February 2008 was extracted from the EGB. Drugs were classified as inappropriate using the French PIM list. A PIM user was defined as a person receiving at least one PIM reimbursement during the study period. Interregion variability was estimated from logistic regression.

RESULTS

In 53.6% (95% CI: 53.0-54.1) of the elderly aged 75 years and over, at least one PIM was given during the study period. The three main drug groups identified were cerebral vasodilators (19.4%), drugs with antimuscarinic properties (19.3%), and long half-life benzodiazepines (17.8%). There was an important disparity in PIM prescription among the French regions. In 14 out of 22 regions, the risk of PIM prescription was significantly elevated. This geographical variation differed for the different drug groups.

CONCLUSION

PIM prescription in the elderly is a major and worrying problem in France. As in other countries, recent accessibility of the National Insurance Healthcare database makes it possible to create local indicators that the regional health agencies could use to manage public health policy in closer alignment to the needs of the patients within each French region.