Lay views about medicines: the influence of the illness label for the use of generic versus brand.

The aim of this cross-sectional study was to investigate how different types of prescriptions using different illness labels may influence lay views about the use of generic or brand medicines. The participants were 882 Portuguese (both sexes) recruited from the general population, who completed a self-administered questionnaire. A vignette methodology was used in which different prescriptions (generic versus brand) were given for the same label (flu, hypertension, asthma and angina pectoris). The dependent variables were for each illness label: (a) the level of agreement with the prescription, (b) beliefs about the efficacy of a medicine and (c) beliefs about the relief of symptoms. There were main effects of the label and the type of prescription upon beliefs about the use of medicines. There were interactions between illness label and type of medicines. Labels which were perceived as more serious were associated with a lower belief in generic medicines. These results raise important questions concerning the need to consider illness perceptions of lay people (including perceived severity) and its relationship with perceptions of treatment for different conditions. Furthermore, these results may have implications for health-related behaviour in general, and in particular for communication between lay people and health professionals, prescribing behaviour, health costs and adherence to treatment.