Small area variations and welfare loss in the use of outpatient antibiotics.

This article seeks to explain local variations in the use of antibiotics in the community and to assess the welfare loss due to heterogeneous attitudes towards the risk of bacterial resistance. Quarterly data on antibiotic sales from 240 small areas in Switzerland over the course of one year are used. An econometric ad-hoc model with spatial lags is proposed in which the demand for antibiotics varies according to the socioeconomic characteristics of the population, the incidence of infections, antibiotic price and local health care supply. Using residual variations we then evaluate the welfare loss due to varying antibiotic prescription styles. Significant differences are observed in the per capita antibiotic consumption across local areas. Individual income, the demographic structure of the population, physician density and the price of drugs are all relevant determinants. We estimate that unexplained variations may account for 12% of the total antibiotic spending in the community, thus leading to a Euro 6.8 ml loss per year. Understanding the determinants of variations in outpatient antibiotic consumption may help to design more effective policies to counter the threat of bacterial resistance. Our estimate of the welfare loss due to heterogeneous attitudes towards antibiotic treatment is comparable to the expected cost of implementing measures to improve the dissemination of information on bacterial resistance among patients and doctors.