Influence of commercial information on prescription quantity in primary care

In the last few years we have witnessed many publicly-financed health services reaching a crisis point. Thus, drug expenditure is nowadays one of the main concerns of health managers, and its containment one of the first goals of health authorities in western countries. The objective of this study is to identify the effect of the perceived quality stated in commercial information, its uses, and how physicians perceive the influence it has on prescription amounts.

A cross-sectional study of 405 primary care physicians was conducted in Galicia (north-west Spain). The independent variables physician's education and speciality, physician's perception of the quality of available drug information sources, type of practice, and number of patients were collected, through a postal questionnaire. Environmental characteristics of the practice were obtained from secondary sources. Multiple regression models were constructed using as dependent variables two indicators of prescription volume.

The response rate was 75.2%. Prescription amounts was found to be associated with perceived credibility of information provided by medical visitors, regulated physician training, and environmental characteristics of the practice (primary care team practice, urban environment).

The study results suggest that in order to decrease prescription amounts it is necessary to limit the role of pharmaceutical companies in physician training, improve physician education and training, and emphasize more objective sources of information.