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Relative fees and the utilization of physicians' services in Canada.

STUDY QUESTION: The study objective is to estimate the relationship between changes in the relative fee physicians receive for a procedure and the utilization of the procedure. DATA SOURCES/STUDY SETTING: The study uses claims-based, procedure-specific, quarterly, aggregate utilization data for physicians in three specialties and four provinces in Canada for the period 1977-1989. STUDY DESIGN: The unit of analysis is an individual procedure. Multi-variate regression methods for cross-sectional/times-series data are applied to estimate the utilization-fee relationship while controlling for supply- and demand-side determinants of utilization. PRINCIPAL FINDINGS: There is no evidence of a strong, uniform utilization response among the 11 procedures analyzed. The results include a mixture of significant and non-significant fee coefficients, and among the significant coefficients, a mixture of signs is observed. The results are consistent with utility-maximizing behaviour by physicians rather than with profit-maximizing behaviour. CONCLUSIONS: The fact that the direction and degree of the utilization effect associated with changing fees is procedure-specific has direct implications for our ability to develop effective policies to modify physician behaviour that are based primarily on financial incentives, particularly those based on manipulating fees. The study also highlights the limitations of analyses based on aggregate data and suggests methodological approaches that have potential to overcome some of these limitations to fill gaps in our current knowledge.

Canada↗

Explaining the utilisation of dental care. Experiences from the Finnish dental market.

In this paper a model based on the theory of demand for health and of supplier inducement is developed to explain the utilisation of dental care. Of special interest are the effects of money price and various forms of inducement. It is also explored how the results are affected if different model specifications and estimation techniques are applied and what is the most appropriate one, when utilisation is measured by dental expenditure. The data come from a sample of 1779 employees, whose dental expenditure is refunded from 0 to 99.75%. Other things being equal, the methodological choices make a clear difference in parameter estimates. Only a log-linear two-part model and two-part tobit with selectivity were suitable for explaining expenditure and produced quite similar results. Money price elasticity was small, but significant (-0.069). General and personal inducement appear to have a considerable effect on utilisation, but did not have any systematic connection with dentist/population ratio.

Adult↗

Provision of health care services in Austria. A time series approach.

The presented article describes the investigation of three main variables of the health care system in Austria by applying time series analysis. The quantities under consideration are the stock of physicians working in the ambulatory sector, the number of medical services provided and the related costs. The article discusses non-stationarity and unit root tests and presents an outlook for the considered variables. One conclusion to be drawn from the presented analysis is the presence of a stochastic element in the analyzed variables.

Austria↗

How reliable are hospital efficiency estimates? Exploiting the dual to homothetic production.

For scientific use, stochastic frontier estimates of hospital efficiency must be robust to plausible departures from the assumptions made by the investigator. Comparisons of alternative study designs, each well within the 'accepted' range according to current practice, generate similar mean inefficiencies but substantially different hospital rankings. The three alternative study contrasts feature (1) pooling vs partitioned estimates, (2) a cost function dual to a homothetic production process vs the translog, and (3) two conceptually valid but empirically different cost-of-capital measures. The results suggest caution regarding the use of frontier methods to rank individual hospitals, a use that seems to be required for reimbursement incentives, but they are robust when generating comparisons of hospital group mean inefficiencies, such as testing models that compare non-profits and for-profits by economic inefficiency. Demonstrations find little or no efficiency differences between these paired groups: non-profit vs for-profit; teaching vs non-teaching; urban vs rural; high percent of Medicare reliant vs low percent; and chain vs independent hospitals.

Benchmarking↗

Cost-effectiveness analysis with risk aversion.

This paper discusses why, in a medical context, the standard assumption of a risk-neutral social planner is inappropriate and develops a framework for conducting cost-effectiveness (CE) analysis when social planners are risk-averse. This framework demonstrates that if new medical interventions are variance increasing (decreasing), the risk-neutral approach will approve (reject) projects that should be rejected (accepted). This methodology is applied to two medical interventions that have been previously evaluated and considered cost-effective in the published literature. Since both conclusions assumed risk neutrality we determine the level of societal risk-aversion that would be necessary to reject these new interventions and compare these levels to previous estimates of risk-aversion in the economics literature. We find that for reasonable values of the risk-aversion parameter, only one of the two interventions should be approved. It is our recommendation that the cut-off risk aversion parameter (the level of risk-aversion above which a project would be rejected) should become a standard reported figure in future CE studies.

Analysis of Variance↗

Provider payment reform in China: the case of hospital reimbursement in Hainan province.

This paper develops a simple model of payment incentives and empirically evaluates provider payment reform in Hainan Province, China. We use a pre-post study design with a control group to analyse two years of claims data to assess the impact of a January 1997 change to prospective payment for a sub-sample of the hospitals. This difference-in-difference empirical strategy allows us to isolate the supply-side payment reform effects from demand-side changes, in contrast with previous studies of China's reforms. Our results validate the theory that Chinese providers' behavioural response to payment incentives is similar to that reported in the literature derived from the experience of industrialized countries. We find that prepayment is associated with a slower rate of growth of overall expenditures, programme spending and patient co-payments per inpatient admission, compared to fee-for-service (FFS). These findings suggest cautious optimism regarding the effectiveness of prospective payment for controlling costs and should be encouraging for policymakers in developing and transitional economies considering replacement of FFS with more aggregated forms of provider payment.

China↗

Estimating hospital costs with a generalized Leontief function.

This paper estimates a long-run hospital cost function with multiple outputs and inputs using a panel data set from Washington State hospitals during 1988-1993. We find that with our data the generalized Leontief function is more appropriate than a translog for estimating hospital cost functions. With respect to hospital costs, we find that hospitals readily adjust the use of intermediate products. Radiology, therapies and surgery, and other inpatient days, all serve as substitutes for core inpatient days. Outpatient services are found to be complementary to core inpatient services, indicating that the growth of stand-alone outpatient clinics might increase the costs of providing healthcare services. Our analysis finds that hospitals show significant economies of scale, but there is a limited amount of evidence of scope economies. Also, there is some evidence that profit-seeking hospitals achieve some of their goals by controlling costs, and that diagnostically related groups (DRG)-based Medicare services are effective in getting hospitals to control costs.

Ambulatory Care↗

Cost efficiency of US hospitals: a stochastic frontier approach.

This study examined the impact of managed care and other environmental factors on hospital inefficiency in 1631 US hospitals during the period 1990-1996. A panel, stochastic frontier regression model was used to estimate inefficiency parameters and inefficiency scores. The results suggest that mean estimated inefficiency decreased by about 28% during the study period. Inefficiency was negatively associated with health maintenance organization (HMO) penetration and industry concentration. It was positively related with Medicare share and for-profit ownership status.

Cost-Benefit Analysis↗

The impact of problem drinking on employment.

Social cost studies report that alcohol use and misuse impose a great economic burden on society, and over half of the total economic costs are estimated to be due to the loss of work productivity. Controversy remains, however, as to the magnitude and direction of the effects of alcohol consumption on productivity. Furthermore, most of the studies have looked at the relationship between problem drinking and wages. This paper investigates the impact of problem drinking on employment by analysing a random sample of men and women of prime working age from six Southern states in the US (Alabama, Arkansas, Georgia, Louisiana, Mississippi and Tennessee). The data set contains 4898 females and 3224 males, with information on both employment and problem drinking. To eliminate the bias that may result from single-equation estimation, we used a bivariate probit model to control for possible correlation in the unobservable factors that affect both problem drinking and employment. We find no significant negative association between problem drinking and employment for both men and women, controlling for other covariates. The findings are consistent with other research and highlight several methodological issues. Furthermore, the study suggests that estimates of the costs of problem drinking may be overstated owing to misleading labour supply relationships.

Adult↗

The impact of income inequality on individual and societal health: absolute income, relative income and statistical artefacts.

The relative income hypothesis, that relative income has a direct effect on individual health, has become an important part of the literature on health inequalities. This paper presents a four-quadrant diagram, which shows the effect of income, relative income and aggregation bias on individual and societal health. The model predicts that increased income inequality reduces average health regardless of whether relative income affects individual health. If relative income does have a direct effect then societal health will decrease further.

Data Collection↗

Cost prediction models for the comparison of two groups.

For trial-based economic evaluation where patient-specific cost data are not routinely available, cost prediction models are commonly used to estimate total cost for each patient. Typically, multiple regression techniques are used on data from diagnosis-matched, non-trial patients (where patient-level cost data are available) to model cost as a function of covariates that are observed on the trial subjects (e.g. length of hospital stay, procedures, etc.). The estimated beta coefficients provide a means of estimating the total cost for each patient in the trial. However, the variability of the beta coefficients due the measurement and sampling error is seldom included in the overall variance expression for mean costs by treatment group. In this paper we provide a method for estimating this variance and provide an example application

Angina, Unstable↗

A framework for cost-effectiveness analysis from clinical trial data.

We present a general Bayesian framework for cost-effectiveness analysis (CEA) from clinical trial data. This framework allows for very flexible modelling of both cost and efficacy related trial data. A common CEA technique is established for this wide class of models through linking mean efficacy and mean cost to the parameters of any given model. Examples are given in which efficacy may be measured as a continuous, binary, ordinal or time-to-event outcome, and in which costs are modelled as distributed normally, log-normally, as a mixture or non-parametrically. A case study is presented, illustrating the methodology and illuminating the role of prior information.

Bayes Theorem↗

Discounting for health effects in cost-benefit and cost-effectiveness analysis.

When health effects can be valued in monetary terms, as in cost-benefit analysis, they should be discounted at the same rate as costs. If health effects are measured in quantities (e.g. quality adjusted life years) as in cost-effectiveness analysis (CEA) and the value of health effects is increasing over time, discounting the volume of health effects at a lower rate than costs is a valid method of taking account of the increase in the future value of health effects. We show that the Keeler-Cretin paradox, often used as an argument against discounting health effects at a lower rate than costs, has no relevance for the choice of discount rate in CEA. We present individualistic and welfare models to argue that the rate of growth of the value of health effects is positive. The welfare model suggests that the value of health grows at a rate dependent on the rate of growth of the value of the direct effect of health on utility, the growth rate of income, the elasticity of the marginal utility of income and the extent to which individuals are insured against the income risks of ill health.

Cost-Benefit Analysis↗

Changing the first line drug for malaria treatment--cost-effectiveness analysis with highly uncertain inter-temporal trade-offs.

Access to effective treatment would substantially reduce the burden of malaria in sub-Saharan Africa, but resistance to chloroquine, the most commonly used first line drug, is now widespread. There has been considerable debate over the level of chloroquine resistance at which a new first line drug should be adopted. Two issues make this an extremely complex decision: it involves trade-offs in costs and health outcomes over time; and many of the parameters are uncertain. A modelling approach was identified as appropriate for addressing these issues. The costs and effects of changing from chloroquine to sulphadoxine-pyrimethamine (SP) as the first line drug were modelled over 10 years, allowing for growth in drug resistance. Probabilistic sensitivity analysis was used to allow for the high levels of parameter uncertainty. The optimal year of switch was highly dependent on both empirical values, such as initial resistance and resistance growth rates, and on subjective values, such as the time preferences of policy-makers. It was not possible to provide policy-makers with a definitive threshold resistance level at which to switch, but the model can be used as an analytical tool to structure the problem, explore trade-offs, and identify areas for which data are lacking.

Africa South of the Sahara↗

Economic evaluations of hepatitis B immunization: a global review of recent studies (1994-2000).

A search was carried out for economic evaluations of hepatitis B (HBV) vaccination, published between 1994 and 2000. The results of these studies are discussed according to the level of HBV endemicity. The great majority of these evaluations were carried out for industrialized countries, for the most part situated in areas of low to very low HBV endemicity. In countries of very low endemicity economic evaluations have yielded contradictory results, depending on the type of epidemiological model they used. The cost-effectiveness of adding universal to selective vaccination strategies in these countries depends on the selective strategies' ability to sufficiently identify, reach and fully vaccinate persons in various risk groups. In areas of low, intermediate and high endemicity, universal vaccination seems justifiable on the basis of economic evaluation. In general, the accuracy of the models has improved over the years, but still the transparency, completeness and comparability of analyses could improve considerably. By noting this, the suitability of different methodologies for different areas of endemicity and vaccination strategies is discussed. It is recommended that specific guidelines for economic evaluation of the prevention of infectious diseases be developed to guarantee the relevance of and to improve the comparability between studies.

Cost-Benefit Analysis↗

The effect of variable health insurance deductibles on the demand for physician visits.

In order to contain cost in the health care sector, the introduction of consumer incentives in health insurance has been suggested and realized in many countries. The Swiss health system reform of 1996 introduced a choice of deductible for health services in the mandatory basic health insurance. This paper estimates the effect of this choice on physician service utilization. A generalized method of moments (GMM) estimator is applied to take account of the endogeneity of the choice of the deductible in the estimation of the number of physician visits. This paper finds that most of the observed reduction in the number of physician visits among individuals who choose a higher deductible seems to be a result of self-selection of individuals into the respective insurance contracts, and not to induced changes in utilization behaviour.

Adolescent↗

Effects of cost sharing on physician utilization under favourable conditions for supplier-induced demand.

The effects of cost sharing on the demand for ambulatory care in experimental circumstances are well understood since the Rand Health Insurance Experiment (HIE). However, in a non-experimental real-world context, supplier-induced demand of doctors might erode some of the significant negative out-of-pocket price elasticity identified in the HIE. Belgium is an interesting test case for this hypothesis because it has relatively high rates of patient cost sharing in its public health insurance system and a very high density of physicians, all remunerated fee-for-service. We have exploited the price variation generated by a substantial increase in patient co-payment rates in 1994 to estimate out-of-pocket price elasticities for three groups of users, and for three types of services using a fixed-effects model in levels and in differences. We obtain significant out-of-pocket price elasticities for the general population in the range from -0.39 to -0.28 for GP home visits, -0.16 to -0.12 for GP office visits and -0.10 for specialist visits. The estimates were generally lower and less significant for the groups of elderly and disabled. The differences we find in price responsiveness appear to be fairly robust and consistent with the HIE predictions. These results suggest that--at least in the short run--non-experimental utilization effects of cost sharing are very similar to the experimental evidence, even in a situation of favourable conditions for supplier-induced demand.

Ambulatory Care↗

Representing uncertainty: the role of cost-effectiveness acceptability curves.

Decision-making in health care is inevitably undertaken in a context of uncertainty concerning the effectiveness and costs of health care interventions and programmes. One method that has been suggested to represent this uncertainty is the cost-effectiveness acceptability curve. This technique, which directly addresses the decision-making problem, has advantages over confidence interval estimation for incremental cost-effectiveness ratios. However, despite these advantages, cost-effectiveness acceptability curves have yet to be widely adopted within the field of economic evaluation of health care technologies. In this paper we consider the relationship between cost-effectiveness acceptability curves and decision-making in health care, suggest the introduction of a new concept more relevant to decision-making, that of the cost-effectiveness frontier, and clarify the use of these techniques when considering decisions involving multiple interventions. We hope that as a result we can encourage the greater use of these techniques.

Confidence Intervals↗