[Acceptance of generic prescribing in general practice: effect of patient education and reference prices]

To assess patient acceptance of the substitution of brand-name drugs for generic equivalents in the context of repeat prescriptions for chronic diseases.

A prospective multicenter study of drug use was performed. Of the 31 centers included in the study, 8 were randomized to the intervention group and 23 to the control group. For 1 year, patients in the intervention group who visited the center to collect repeat prescriptions received verbal and written information on the advantages and disadvantages of generic and brand name drugs. Data on the number of patients taking brand-name drugs for which generic equivalents were available, as well as the reasons and variables related to refusal of generic drugs (age, gender, education, primary care centre, general practitioner, type of drug and total number of repeat prescriptions) were collected. The percentage of generic drugs among the total number of drugs prescribed was calculated at 2-monthly intervals.

A total of 98.9% of the 4620 patients in the intervention group agreed to change to a generic formulation. The percentage of patients accepting generic drugs was significantly associated with the primary care centre, the class of drug, doctors' influence, and patient satisfaction with the drug. Generic prescriptions represented 5.9% in the intervention practices compared with 2.8% in controls. After the intervention, and before the application of reference prices, the percentages were 6.7% and 3.9%, respectively. Immediately after application of the reference prices, the percentages were 8.6% and 6.3%, respectively.

Direct patient education is an effective strategy in increasing the prescription of generic equivalents. General practitioners' motivation and knowledge of generic drugs influenced their use. The application of reference prices increased the use of generic equivalents.