Disentangling spillover effects 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 where 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 fixed effects (FE). The implications of consumption externalities across geographical areas are investigated by means of spatial-lag and spatial-error models (SLFE and SEFE). We find significant and positive income elasticity and negative effects of copayments. Antibiotic use is also affected by the age structure of the population and the supply of community health care. Finally, we find evidence of spatial dependency in the use of antibiotics across regions. This suggests that regional policies (e.g. public campaigns) aimed at increasing efficiency in antibiotic consumption and controlling bacterial resistance may be influenced by policy makers in neighbouring regions. There will be scope for a strategic and coordinated view of regional policies towards the use of antibiotics.Antibiotic consumption, Socioeconomic inequalities, Spatial dependency, Regional policies.

Estimating dynamic consumption of antibiotics using panel data: the shadow effect of bacterial resistance

To some extent, antibiotics are similar to addictive goods since current consumption is reinforced by past use because of bacterial resistance, which represents a growing concern in many countries. The purpose of this paper is to explore how consumers adjust their current level of antibiotic consumption towards desired levels over time. We construct a balanced panel dataset (2000-2007) for 20 Italian regions and estimate a dynamic model where antibiotic consumption depends upon demographic and socioeconomic characteristics of the population, the supply of health care in the community, antibiotic price, and the "capital stock" of endogenous bacterial resistance measured by past consumption. We apply alternative dynamic estimators for short panels: the bias-corrected least squares dummy variable (LSDVC) and the system Blundell-Bond GMM estimator (GMM-BB). The estimation results are stable across different model specifications and show that antibiotic use in previous periods has a positive impact on current antimicrobial consumption (between 0.14 and 0.39). This indicates that the process of adjustment to desired levels of consumption is relatively fast (approximately 1.2-1.6 years). Weak persistence in consumption may suggest that individuals are responsive to changes in antibiotic effectiveness.Antibiotic consumption, bacterial resistance, dynamic model

Characteristics of demand for antibiotics in primary care: an almost ideal demand system approach

We model demand for different classes of antibiotics used for respiratory infections in outpatient care using a linear approximate almost ideal demand system approach. We compute elasticities to socioeconomic determinants of consumption and own- and cross- price elasticities between different groups of antibiotics. We find significant elasticities between newer/more expensive generations and older/less expensive generations of antibiotics. The larger use of more expensive antibiotics is also associated with the self-dispensing status of practices, ceteris paribus.Antibiotic use, Demand equations, Demand elasticities, Almost Ideal Model, Self-dispensing

Dispensing practices and antibiotic use

The regulation on prescribing and dispensing of antibiotics has a double purpose: to enhance access to antibiotic treatment and to reduce the inappropriate use of drugs. Nevertheless, incentives to dispensing physicians may lead to inefficiencies. We sketch a theoretical model of the market for antibiotic treatment and empirically investigate the impact of self-dispensing on the per capita outpatient antibiotic consumption using data from small geographic areas in Switzerland. We find evidence that a greater proportion of dispensing practices is associated with higher levels of antibiotic use. This suggests that health authorities have a margin to adjust economic incentives on dispensing practices in order to reduce antibiotic misuse.Dispensing, Antibiotic use

Physician dispensing and antibiotic prescriptions

The regulation on prescribing and dispensing of antibiotics has a double purpose: to enhance access to antibiotic treatment and to reduce the inappropriate use of drugs. Nevertheless, incentives to dispensing physicians may lead to inefficiencies. We sketch a theoretical model of the market for antibiotic treatment and empirically investigate the impact of self-dispensing on the per capita outpatient antibiotic consumption using data from small geographic areas in Switzerland. We find evidence that a greater proportion of dispensing practices is associated with higher levels of antibiotic use. This suggests that health authorities have a margin to adjust economic incentives on dispensing practices in order to reduce antibiotic misuse.Physician dispensing, Antibiotic use

Small area variations and welfare loss in the use of antibiotics in the community

This paper 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 infections and resistance. Significant differences are observed in the per capita antibiotic consumption measured in defined daily doses per 1000 inhabitants (DID) across small geographic areas in Switzerland. A model is proposed in which antibiotic use varies according to the socioeconomic characteristics of the population, the incidence of infections, antibiotic price and local supply of health care. Quarterly wholesales data on outpatient antibiotics in 2002 were obtained from IHA-IMS Market Research and combined with WHO standardized doses to obtain DID. The paper finds that the most important determinants of variations in outpatient antibiotics use in the community are income, demographic structure of the population and local supply and price of antibiotic treatment. We estimated that unexplained variations may account for 11% of the total antibiotic spending in the community, thus leading to a €6ml loss per year.antibiotic use, small area variations, welfare loss

Determinants of outpatient antibiotic consumption in Europe: bacterial resistance and drug prescribers

This paper investigates socioeconomic determinants of outpatient antibiotic consumption in Europe. Comparable data on antibiotic use measured in the defined daily doses per 1000 inhabitants (DID) are currently provided by the ESAC project. Results from applied econometric estimations for panel data reveal a link between antibiotic use and the per capita income, the demographic structure of the population, the level of education and cultural aspects. Supply-side factors, such as the density of providers and their remuneration methods, are also considered. We provide the first estimate of the impact of bacterial resistance on consumption when the e?ect of other determinants is simultaneously taken into account.Antibiotic use, Cross-country variations, Bacterial resistance, Supply-induced demand

Quality incentives in a regulated market with imperfect information and switching costs: capitation in general practice

We model a system akin to the British National Health Service in which general practictioners (GPs) are paid from general taxation. GPs are horizontally and vertically differentiated and compete via their imperfect observed quality. We focus on the way in which patient uncertainty and switching costs interact and the implications for GP's choice of quality. We show that for any given capitation fee quality is lower and the incentive effects of the fee on quality are smaller. There are diminishing welfare gains from improving consumers information but increasing welfare gains from reducing switching costs. GPs do not act efficiently to improve consumer information via advertising or to reduce the costs of switching.Switching costs; Imperfect information; Quality; Product differentiation; Capitation; General Practice

Habits and rational behavior in residential electricity demand

Households make an investment analysis when buying new electrical appliances. Therefore, expectations about future electricity consumption may have an impact on current consumption and investment decisions. Dynamic partial adjustment models of residential electricity demand neglect rational consumer behavior. In this paper we propose a model for residential electricity demand that allows for forward-looking behavior. We estimate lead consumption models using two stages least squares fixed effects on a panel of 48 US states between 1995 and 2011. We find that expectations about future consumption have an impact on current consumption decisions. This novel approach may improve our understanding of the dynamics of residential electricity demand and the evaluation of the effects of energy policies

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 ₠ 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 doctor