Disentangling spillover e¤ects of antibiotic consumption: a spatial panel approach

Literature on socioeconomic determinants of antibiotic consumption in the community is limited to few countries using cross-sectional data. This paper analyses regional variations in outpatient antibiotics in Italy using a balanced panel dataset covering the period 2000-2008. We specify an econometric model in which antibiotic consumption depends upon demographic and socioeconomic characteristics of the population, the supply of health care services in the community, and antibiotic copayments. The model is estimated by means of Ordinary least squares techniques with …xed e¤ects (FE). The implications of consumption externalities across geographical areas are investigated by means of spatial-lag and spatial-error models (SLFE and SEFE). We …nd signi…cant and positive income elasticity and negative e¤ects of copayments. Antibiotic use is also a¤ected by the age structure of the population and the supply of community health care. Finally, we …nd evidence of spatial dependency in the use of antibiotics across regions. This suggests that regional policies (e.g. public campaigns) aimed at increasing e¢ ciency in antibiotic consumption and controlling bacterial resistance may be in‡uenced by policy makers in neighbouring regions. There will be scope for a strategic and coordinated view of regional policies towards the use of antibiotics. Keywords: antibiotic consumption; socioeconomic inequalities; spatial dependency; regional policies JEL classi…cation: C21; C23; I11; I18; R00 Department of Economics, University of Lugano, 6900 Lugano, Switzerland yDepartment of Economics and Technology Management, University of Bergamo, 24044 Dalmine (BG), Italy; Department of Economics, University of Lugano, 6900 Lugano, Switzerland. Corresponding author. E-mail: [email protected]. We are grateful to Massimo Filippini whose comments and suggestions generated signi…cant improvements to the paper. Comments and suggestions from participants to the 11th National Health Economics Conference of the Portuguese Health Economics Association, Porto, 8-10 October 2009, and the 10th National Health Economics Conference of the Italian Health Economics Association, Bergamo, 29-30 October 2009, are gratefully acknowledged. The usual caveat applies.