Showing papers in "Health Economics in 2004"
TL;DR: A 'gallery' of CEACs is presented in order to identify the fallacies and illustrate the facts surrounding the CEAC to serve as a reference tool to accompany the increased use ofCEACs within major medical journals.
Abstract: Cost-effectiveness acceptability curves (CEACs) have been widely adopted as a method to quantify and graphically represent uncertainty in economic evaluation studies of health-care technologies. However, there remain some common fallacies regarding the nature and shape of CEACs that largely result from the ‘textbook’ illustration of the CEAC. This ‘textbook’ CEAC shows a smooth curve starting at probability 0, with an asymptote to 1 for higher money values of the health outcome (λ). But this familiar ‘ogive’ shape which makes the ‘textbook’ CEAC look like a cumulative distribution function is just one special case of the CEAC. The reality is that the CEAC can take many shapes and turns because it is a graphic transformation from the cost-effectiveness plane, where the joint density of incremental costs and effects may ‘straddle’ quadrants with attendant discontinuities and asymptotes. In fact CEACs: (i) do not have to cut the y-axis at 0; (ii) do not have to asymptote to 1; (iii) are not always monotonically increasing in λ; and (iv) do not represent cumulative distribution functions (cdfs). Within this paper we present a ‘gallery’ of CEACs in order to identify the fallacies and illustrate the facts surrounding the CEAC. The aim of the paper is to serve as a reference tool to accompany the increased use of CEACs within major medical journals. Copyright © 2004 John Wiley & Sons, Ltd.
831 citations
TL;DR: A comparison of the EQ-5D and the SF-6D across seven patient/population groups (chronic obstructive airways disease, osteoarthritis, irritable bowel syndrome, lower back pain, leg ulcers, post menopausal women and elderly) shows discrepancies arise from differences in their health state classifications and the methods used to value them.
Abstract: As the number of preference-based instruments grows, it becomes increasingly important to compare different preference-based measures of health in order to inform an important debate on the choice of instrument. This paper presents a comparison of two of them, the EQ-5D and the SF-6D (recently developed from the SF-36) across seven patient/population groups (chronic obstructive airways disease, osteoarthritis, irritable bowel syndrome, lower back pain, leg ulcers, post menopausal women and elderly). The mean SF-6D index value was found to exceed the EQ-5D by 0.045 and the intraclass correlation coefficient between them was 0.51. Whilst this convergence lends some support for the validity of these measures, the modest difference at the aggregate level masks more significant differences in agreement across the patient groups and over severity of illness, with the SF-6D having a smaller range and lower variance in values. There is evidence for floor effects in the SF-6D and ceiling effects in the EQ-5D. These discrepancies arise from differences in their health state classifications and the methods used to value them. Further research is required to fully understand the respective roles of the descriptive systems and the valuation methods and to examine the implications for estimates of the impact of health care interventions.
779 citations
TL;DR: The results suggest a threshold somewhat higher than NICEs stated 'range of acceptable cost effectiveness' of pound 20,000-30,000 British pounds per QALY--although the exact meaning of a 'range' in this context remains unclear.
Abstract: The decisions made by the National Institute for Clinical Excellence (NICE) give rise to two questions: how is cost-effectiveness evidence used to make judgements about the 'value for money' of health technologies? And how are factors other than cost-effectiveness taken into account? The aim of this paper is to explore NICE's cost-effectiveness threshold(s) and the tradeoffs between cost effectiveness and other factors apparent in its decisions. Binary choice analysis is used to reveal the preferences of NICE and to consider the consistency of its decisions. For each decision to accept or reject a technology, explanatory variables include: the cost per life year or per QALY gained; uncertainty regarding cost effectiveness; the net cost to the NHS; the burden of disease; the availability (or not) of alternative treatments; and specific factors indicated by NICE. Results support the broad notion of a threshold, where the probability of rejection increases as the cost per QALY increases. Cost effectiveness, together with uncertainty and the burden of disease, explain NICE decisions better than cost effectiveness alone. The results suggest a threshold somewhat higher than NICEs stated 'range of acceptable cost effectiveness' of pound 20,000-30,000 British pounds per QALY--although the exact meaning of a 'range' in this context remains unclear.
718 citations
Journal Article•
TL;DR: New international comparative evidence on the factors driving inequalities in the use of GP and specialist services in 12 EU member states is presented, finding little or no evidence of income-related inequity in the probability of a GP visit in these countries.
Abstract: This paper presents new international comparative evidence on the factors driving inequalities in the use of GP and specialist services in 12 EU member states. The data are taken from the 1996 wave of the European Community Household Panel (ECHP). We examine two types of utilisation (the probability of a visit and the conditional number of positive visits) for two types of medical care: general practitioner and medical specialist visits using probit, truncated Negbin and generalised Negbin models. We find little or no evidence of income-related inequity in the probability of a GP visit in these countries. Conditional upon at least one visit, there is even evidence of a somewhat pro-poor distribution. By contrast, substantial pro-rich inequity emerges in virtually every country with respect to the probability of contacting a medical specialist. Despite their lower needs for such care, wealthier and higher educated individuals appear to be much more likely to see a specialist than the less well-off. This phenomenon is universal in Europe, but stronger in countries where either private insurance cover or private practice options are offered to purchase quicker and/or preferential access. Pro-rich inequity in subsequent visits adds to this access inequity but appears more related to regional disparities in utilisation than to other factors. Despite decades of universal and fairly comprehensive coverage in European countries, utilisation patterns suggest that rich and poor are not treated equally.
626 citations
TL;DR: In this paper, the authors present new international comparative evidence on the factors driving inequalities in the use of GP and specialist services in 12 EU member states and find little or no evidence of income-related inequity in the probability of a GP visit in these countries, and there is even evidence of a somewhat pro-poor distribution.
Abstract: This paper presents new international comparative evidence on the factors driving inequalities in the use of GP and specialist services in 12 EU member states. The data are taken from the 1996 wave of the European Community Household Panel (ECHP). We examine two types of utilisation (the probability of a visit and the conditional number of positive visits) for two types of medical care: general practitioner and medical specialist visits using probit, truncated Negbin and generalised Negbin models. We find little or no evidence of income-related inequity in the probability of a GP visit in these countries. Conditional upon at least one visit, there is even evidence of a somewhat pro-poor distribution. By contrast, substantial pro-rich inequity emerges in virtually every country with respect to the probability of contacting a medical specialist. Despite their lower needs for such care, wealthier and higher educated individuals appear to be much more likely to see a specialist than the less well-off. This phenomenon is universal in Europe, but stronger in countries where either private insurance cover or private practice options are offered to purchase quicker and/or preferential access. Pro-rich inequity in subsequent visits adds to this access inequity but appears more related to regional disparities in utilisation than to other factors. Despite decades of universal and fairly comprehensive coverage in European countries, utilisation patterns suggest that rich and poor are not treated equally.
580 citations
TL;DR: A decomposition analysis shows that the (partial) income elasticities of the explanatory variables are generally more important than their unequal distribution by income in explaining the cross-country differences in income-related health inequality.
Abstract: This paper provides new evidence on the sources of differences in the degree of income-related inequalities in self-assessed health in 13 European Union member states. It goes beyond earlier work by measuring health using an interval regression approach to compute concentration indices and by decomposing inequality into its determining factors. New and more comparable data were used, taken from the 1996 wave of the European Community Household Panel. Significant inequalities in health (utility) favouring the higher income groups emerge in all countries, but are particularly high in Portugal and - to a lesser extent - in the UK and in Denmark. By contrast, relatively low health inequality is observed in the Netherlands and Germany, and also in Italy, Belgium, Spain Austria and Ireland. There is a positive correlation with income inequality per se but the relationship is weaker than in previous research. Health inequality is not merely a reflection of income inequality. A decomposition analysis shows that the (partial) income elasticities of the explanatory variables are generally more important than their unequal distribution by income in explaining the cross-country differences in income-related health inequality. Especially the relative health and income position of non-working Europeans like the retired and disabled explains a great deal of 'excess inequality'. We also find a substantial contribution of regional health disparities to socio-economic inequalities, primarily in the Southern European countries.
539 citations
TL;DR: It is found that both men and women experience a persistent obesity wage penalty over the first two decades of their careers, and other variables -- including job discrimination, health-related factors and/or obese workers' behavior patterns -- may be the channels through which obesity adversely affects wages.
Abstract: We use National Longitudinal Survey of Youth (NLSY) data to examine the effects of obesity on wages by gender. Sample means indicate that both men and women experience a persistent obesity wage penalty over the first two decades of their careers. We then control for a standard set of socioeconomic and familial variables but find that standard covariates do not explain why obese workers experience persistent wage penalties. This suggests that other variables -- including job discrimination, health-related factors and/or obese workers' behavior patterns -- may be the channels through which obesity adversely affects wages. The study closes with a discussion of the public policy implications suggested by these findings.
471 citations
TL;DR: This paper examined several alternative approaches to stochastic frontier analysis with panel data, and applied some of them to the World Health Organization's (WHO) panel data set on health care delivery, which is a 191 country, 5-year panel.
Abstract: The most commonly used approaches to parametric (stochastic frontier) analysis of efficiency in panel data, notably the fixed and random effects models, fail to distinguish between cross individual heterogeneity and inefficiency. This blending of effects is particularly problematic in the World Health Organization's (WHO) panel data set on health care delivery, which is a 191 country, 5-year panel. The wide variation in cultural and economic characteristics of the worldwide sample produces a large amount of unmeasured heterogeneity in the data. This study examines several alternative approaches to stochastic frontier analysis with panel data, and applies some of them to the WHO data. A more general, flexible model and several measured indicators of cross country heterogeneity are added to the analysis done by previous researchers. Results suggest that there is considerable heterogeneity that has masqueraded as inefficiency in other studies using the same data.
375 citations
TL;DR: A direct regression approach to cost-effectiveness analysis is developed by proposing the use of a system of seemingly unrelated regression equations to provide a more general method for prognostic factor adjustment with emphasis on sub-group analysis.
Abstract: The current interest in undertaking cost-effectiveness analyses alongside clinical trials has lead to the increasing availability of patient-level data on both the costs and effectiveness of intervention. In a recent paper, we show how cost-effectiveness analysis can be undertaken in a regression framework. In the current paper we develop a direct regression approach to cost-effectiveness analysis by proposing the use of a system of seemingly unrelated regression equations to provide a more general method for prognostic factor adjustment with emphasis on sub-group analysis. This more general method can be used in either an incremental cost-effectiveness or an incremental net-benefit approach, and does not require that the set of independent variables for costs and effectiveness be the same. Furthermore, the method can exhibit efficiency gains over unrelated ordinary least squares regression.
304 citations
TL;DR: Using a longitudinal hospital data set from Oxfordshire, England, the two-step Heckman model from the Zweifel study is first replicated, to find that neither age nor proximity to death have a significant effect on hospital costs, and instead a two-part model shows both age and proximity todeath to have significant effects on quarterly hospital costs.
Abstract: Zweifel and colleagues have previously proposed that proximity to death is a more important influence on health-care costs than age, suggesting that demographic change per se will not have a large impact on future aggregate health expenditure. However, issues of econometric methodology have led to challenges of the robustness of these findings. This paper revisits the analysis. Using a longitudinal hospital data set from Oxfordshire, England, the two-step Heckman model from the Zweifel study is first replicated, to find that neither age nor proximity to death have a significant effect on hospital costs. Econometric problems with the model are demonstrated, and instead a two-part model shows both age and proximity to death to have significant effects on quarterly hospital costs. Cost predictions, calculated with bootstrapped 95% confidence intervals, further demonstrate that while age may significantly affect quarterly costs, these cost changes are small compared to the tripling of quarterly costs that occurs with approaching death in the last year of life. The analyses show the importance of model selection to properly assess the determinants of health-care expenditures.
289 citations
TL;DR: A new redistribution interpretation and an existing redistribution interpretation of the Gini are presented and applied to the concentration index and the relationship between a concentration index, a correlation coefficient with relative income rank and a coefficient of variation of the variable of interest is illustrated.
Abstract: This paper aims to add a more intuitive understanding to the concept of a concentration index for measuring relative inequality with an application of health-related measures by income. A new redistribution interpretation and an existing redistribution interpretation of the Gini are presented and applied to the concentration index. Both indicate the share of the total amount of any variable that needs redistributing in a particular way from rich to poor (or vice versa) to achieve a concentration index equal to zero. The characteristics of these redistribution schemes are compared. The paper also draws attention to the relationship between a concentration index, a correlation coefficient with relative income rank and a coefficient of variation of the variable of interest. These relationships are illustrated using data on inequality in dental care utilisation in European countries taken from the European Community Household Panel survey.
TL;DR: The ways in which preference-based health status (utility) data are used to generate quality adjusted life years (QALYs) are examined, finding the methodology employed was not always consistent, as well as being poorly reported.
Abstract: Economic evaluations alongside randomised controlled trials (RCTs) are increasingly being designed to prospectively collect patient-specific resource use and preference-based health status (utility) data. This paper examines the ways in which preference-based health status (utility) data are used to generate quality adjusted life years (QALYs). A literature review was carried out which identified 23 published cost utility analyses suitable for inclusion. The methodology employed to calculate QALYs was not always consistent, as well as being poorly reported. The use of different methodologies in the calculation of QALYs may influence the magnitude and direction of results of evaluations. Analysts need to be consistent and fully transparent in the methodology chosen to calculate QALYs.
TL;DR: In this article, the authors explore the empirical implications of incorporating time to death in longitudinal models of health expenditures for the purpose of predicting future expenditures, and show that the predicted differences between the models are sufficient to justify reassessment of the value of inclusion of time-to-death in models for predicting health care expenditures.
Abstract: Government projections of future health care expenditures--a great concern given the aging baby-boom generation--are based on econometric regressions that control explicitly for age but do not control for end-of-life expenditures. Because expenditures increase dramatically on average at the end of life, predictions of future cost distributions based on regressions that omit time to death as an explanatory variable will be biased upward (or, more explicitly, the coefficients on age will be biased upward) if technology or other social factors continue to prolong life. Although health care expenditure predictions for a current sample will not be biased, predictions for future cohorts with greater longevity will be biased upwards, and the magnitude of the bias will increase as the expected longevity increases. We explore the empirical implications of incorporating time to death in longitudinal models of health expenditures for the purpose of predicting future expenditures. Predictions from a simple model that excludes time to death and uses current life tables are 9% higher than from an expanded model controlling for time to death. The bias increases to 15% when using projected life tables for 2020. The predicted differences between the models are sufficient to justify reassessment of the value of inclusion of time to death in models for predicting health care expenditures.
TL;DR: This paper outlines a framework for comparing empirically overall health inequality and socioeconomic health inequality, and is illustrated using data on malnutrition amongst Vietnamese children and on health utility amongst Canadian adults.
Abstract: This paper outlines a framework for comparing empirically overall health inequality and socioeconomic health inequality. The framework, which is developed for both individual-level data and grouped data, is illustrated using data on malnutrition amongst Vietnamese children and on health utility amongst Canadian adults. In both cases, the degree of socioeconomic inequality is estimated at around 25% of overall inequality.
TL;DR: This paper investigated the effects of supplemental private health insurance on the utilization of physician services using data from the 1998 Enquete sur la sante et la protection sociale, a nationally representative survey of the non-institutionalized French population.
Abstract: In France, public health insurance is universal but incomplete, with private payments accounting for roughly 25% of all spending. As a result, most people have supplemental private health insurance. We investigate the effects of such insurance on the utilization of physician services using data from the 1998 Enquete sur la sante et la protection sociale, a nationally representative survey of the non-institutionalized French population. Our results indicate that insurance has a strong and significant effect on the utilization of physician services. Individuals with supplemental coverage have substantially more physician visits than those without. While French patients have greater freedom than patients in other countries to choose to see a specialist rather than a general practitioner, we find no evidence that supplemental insurance affects this decision.
TL;DR: It is found that the proportional hazard assumption is an essential requirement to obtain consistent estimate of the E(y|x) using the Cox model.
Abstract: Health economists often use log models (based on OLS or generalized linear models) to deal with skewed outcomes such as those found in health expenditures and inpatient length of stay. Some recent studies have employed Cox proportional hazard regression as a less parametric alternative to OLS and GLM models, even when there was no need to correct for censoring. This study examines how well the alternative estimators behave econometrically in terms of bias when the data are skewed to the right. Specifically we provide evidence on the performance of the Cox model under a variety of data generating mechanisms and compare it to the estimators studied recently in Manning and Mullahy (2001). No single alternative is best under all of the conditions examined here. However, the gamma regression model with a log link seems to be more robust to alternative data generating mechanisms than either OLS on ln(y) or Cox proportional hazards regression. We find that the proportional hazard assumption is an essential requirement to obtain consistent estimate of the E(y|x) using the Cox model.
TL;DR: This work describes an alternative method of deriving measures of welfare (compensating variation) from DCEs that is consistent with RUT and is derived using welfare theory and demonstrates its use in an empirical application to derive the WTP for asthma medication.
Abstract: Discrete choice experiments (DCEs) are being used increasingly in health economics to elicit preferences for products and programs. The results of such experiments have been used to calculate measures of welfare or more specifically, respondents' 'willingness to pay' (WTP) for products and programs and their 'marginal willingness to pay' (MWTP) for the attributes that make up such products and programs. In this note we show that the methods currently used to derive measures of welfare from DCEs in the health economics literature are not consistent with random utility theory (RUT), or with microeconomic welfare theory more generally. The inconsistency with welfare theory is an important limitation on the use of such WTP estimates in cost-benefit analyses. We describe an alternative method of deriving measures of welfare (compensating variation) from DCEs that is consistent with RUT and is derived using welfare theory. We demonstrate its use in an empirical application to derive the WTP for asthma medication and compare it to the results elicited from the method currently used in the health economics literature.
TL;DR: Joint analyses highlight how stated preference data can be used to estimate parameters for attributes that are not observed in the marketplace, that do not vary in the Marketplace, or that are highly collinear with other attributes in actual markets.
Abstract: The use of stated preference analyses to evaluate choice of health care products has been growing in recent years. This paper shows how revealed preference data can be enriched with stated preference data and highlights the relative advantages of revealed and stated preference data. The techniques were applied to a study of determinants of physicians' prescriptions of alcoholism medications. Analyses were conducted on the relationship between physicians' perceptions of existing alcoholism medication attributes and their prescribing rates of those medications. Analyses were also conducted on physicians' decisions to prescribe hypothetical alcoholism medications with varying attributes such as efficacy, side effects, compliance, mode of action, and price. Finally, analyses were conducted on the combined stated and revealed preference data. Joint estimation suggests that parameters from the revealed and stated preference data are equal, up to scale. Joint analyses highlight how stated preference data can be used to estimate parameters for attributes that are not observed in the marketplace, that do not vary in the marketplace, or that are highly collinear with other attributes in actual markets.
TL;DR: The authors investigated the relationship between the demands for alcohol and marijuana for college students using data from the 1993, 1997 and 1999 waves of the Harvard School of Public Health's College Alcohol Study (CAS).
Abstract: Previous research has shown that the recent tightening of college alcohol policies has been effective at reducing college students' drinking. Over the period in which these stricter alcohol policies have been put in place, marijuana use among college students has increased. This raises the question of whether current policies aimed at reducing alcohol consumption are inadvertently encouraging marijuana use. This paper begins to address this question by investigating the relationship between the demands for alcohol and marijuana for college students using data from the 1993, 1997 and 1999 waves of the Harvard School of Public Health's College Alcohol Study (CAS). We find that alcohol and marijuana are economic complements and that policies that increase the full price of alcohol decrease participation in marijuana use.
TL;DR: The results indicate that, overall, insured patients are more likely to use outpatient facilities, and public providers, an effect that is particularly strong at lower income levels.
Abstract: This paper analyses the effect of being insured under the voluntary component of Vietnamese Health Insurance, on patterns of treatment seeking behaviour. A multinomial logit model is estimated using household survey data from three provinces in Vietnam. Decisions regarding both the type of provider sought and type of care received are analysed. Insurance status is treated as both exogenous and endogenous to account for potential selection bias. The results indicate that, overall, insured patients are more likely to use outpatient facilities, and public providers, an effect that is particularly strong at lower income levels.
TL;DR: The differences-in-differences estimates indicate that increased co-payments reduced the number of doctor visits by about 10% on an average.
Abstract: The German health care reform of 1997 provides a natural experiment for evaluating the price sensitivity of demand for physicians' services. As a part of the reform, co-payments for prescription drugs were increased step up to 200%. However, certain groups of people were exempted from the increase, providing a natural control group against which the changed demand for physicians' services of the treated, those subject to increased co-payments, can be assessed. The differences-in-differences estimates indicate that increased co-payments reduced the number of doctor visits by about 10% on an average.
TL;DR: It is shown that problem drinking defined by the observed psychological and physical symptoms of alcohol is an important predictor of employment, and allows for the fact that individuals differ in their tolerance or susceptibility to alcohol.
Abstract: In this paper, we use data from the Health Survey of England to show that problem drinking is negatively and significantly associated with the probability of being in work, once the endogenous relationship between these outcomes is accounted for. Being a problem drinker leads to a substantial reduction in the probability of working by between 7 and 31%, the former figure being roughly equivalent to the positive effect of having a degree relative to no qualifications in our data. This finding is robust to a variety of identifying restrictions and definitions of problem drinking. Moreover, we find that problem drinking defined by the observed psychological and physical symptoms of alcohol is an important predictor of employment, and allows for the fact that individuals differ in their tolerance or susceptibility to alcohol. Our results suggest that there may be important labour market benefits from public health policies aimed at the prevention and treatment of problem drinking.
TL;DR: Issues raised in the modelling of such data within an experiment looking at women's preferences for cervical screening services are explored.
Abstract: Discrete choice experiments have the advantage that they can study preferences in health care where revealed preference data is not readily available. However, as a substitute for actual observed market led data, the experimental set-up for hypothetical situations must mimic the circumstances under which actual choices are made. One situation that a consumer/patient might face is an opt-out option. They might not choose to accept any of the positive actions available and as such will be a non-demander of the health care on offer. This paper explores issues raised in the modelling of such data within an experiment looking at women's preferences for cervical screening services.
TL;DR: It is concluded that the AQoL is probably less well suited to measuring health status in a very elderly population than the EQ-5D, which appears to have more favourable construct validity.
Abstract: As more research is undertaken on the elderly, accurately assessing changes in their quality of life becomes increasingly important. Generic instruments are the most popular method to assess quality of life, and one of the most widely used is the EQ-5D. However, the range of dimensions, sensitivity of scales and completion rates have been raised as concerns when using this measure with the elderly. The AQoL is a newer instrument which offers greater richness in dimensions of health covered, and potentially offers greater sensitivity to changes in quality of life. This paper presents the results of a 'head-to-head' comparison of the EQ-5D and AQoL in terms of practicality, construct validity, agreement (of absolute scores and their change over time) and sensitivity to change, as part of a randomised controlled trial in the elderly. Poor agreement was found between both the absolute scores from each instrument and change in scores over time. Although the AQoL appeared to have more favourable construct validity, the EQ-5D was easier to administer, had a higher completion rate, and appeared more sensitive to change. We conclude that the AQoL is probably less well suited to measuring health status in a very elderly population than the EQ-5D.
TL;DR: Since smoking prevalence is significantly lower than it was a decade ago, price increases are becoming less effective as an inducement for hard-core smokers to quit, although they may respond by decreasing consumption.
Abstract: The objective of this paper is to determine the price sensitivity of smokers in their consumption of cigarettes, using evidence from a major increase in California cigarette prices due to Proposition 10 and the Tobacco Settlement. The study sample consists of individual survey data from Behavioral Risk Factor Survey (BRFS) and price data from the Bureau of Labor Statistics between 1996 and 1999. A zero-inflated negative binomial (ZINB) regression model was applied for the statistical analysis. The statistical model showed that price did not have an effect on reducing the estimated prevalence of smoking. However, it indicated that among smokers the price elasticity was at the level of -0.46 and statistically significant. Since smoking prevalence is significantly lower than it was a decade ago, price increases are becoming less effective as an inducement for hard-core smokers to quit, although they may respond by decreasing consumption. For those who only smoke occasionally (many of them being young adults) price increases alone may not be an effective inducement to quit smoking. Additional underlying behavioral factors need to be identified so that more effective anti-smoking strategies can be developed.
TL;DR: This paper demonstrates how the individual components of decision modelling may be addressed simultaneously in one coherent Bayesian model and evaluated using Markov Chain Monte Carlo simulation implemented in the specialist software WinBUGS.
Abstract: Decision analytical models are widely used in economic evaluation of health care interventions with the objective of generating valuable information to assist health policy decision-makers to allocate scarce health care resources efficiently. The whole decision modelling process can be summarised in four stages: (i) a systematic review of the relevant data (including meta-analyses), (ii) estimation of all inputs into the model (including effectiveness, transition probabilities and costs), (iii) sensitivity analysis for data and model specifications, and (iv) evaluation of the model. The aim of this paper is to demonstrate how the individual components of decision modelling, outlined above, may be addressed simultaneously in one coherent Bayesian model (sometimes known as a comprehensive decision analytical model) and evaluated using Markov Chain Monte Carlo simulation implemented in the specialist software WinBUGS. To illustrate the method described, it is applied to two illustrative examples: (1) The prophylactic use of neurominidase inhibitors for the prevention of influenza. (2) The use of taxanes for the second-line treatment of advanced breast cancer. The advantages of integrating the four stages outlined into one comprehensive decision analytical model, compared to the conventional 'two-stage' approach, are discussed.
TL;DR: There is no evidence that decriminalisation significantly increases participation in marijuana use by either young males or females, or that decriminalization increases the frequency of use among marijuana users.
Abstract: This research examines the responsiveness of the demand for marijuana to changes in its money price and criminal status using data on individuals from the Australian National Drug Strategy's Household Surveys (NDSHS). The results suggest that both the prevalence of marijuana use and the conditional demand for marijuana in the general population are responsive to changes in its money price. Significant differences are found in the effect of price on participation in marijuana use across age-groups, with participation by youth more price sensitive than participation by older age-groups. Similarly, the effect of the legal status of marijuana use on the participation decision is found to differ across age-groups and gender. Specifically, decriminalisation is associated with an increases in the prevalence of use by males over the age of 25. There is no evidence that decriminalisation significantly increases participation in marijuana use by either young males or females, or that decriminalisation increases the frequency of use among marijuana users.
TL;DR: In this paper, the authors show that, at least in some contexts, the choice of welfare indicator can have a large and significant impact on measured inequality in utilization of health services, and also point out the need for more careful research on how different dimensions of SES are related, and on the pathways by which the respective different dimensions impact on health related variables.
Abstract: In recent years, a large body of empirical work has focused on measuring and explaining socio-economic inequalities in health outcomes and health service use. In any effort to address these questions, analysts must confront the issue of how to measure socioeconomic status. In developing countries, socioeconomic status has typically been measured by per capita consumption or an asset index. Currently, there is only limited information on how the choice of welfare indicators affect the analysis of health inequalities and the incidence of public spending. The purpose of this paper is to illustrate the potential sensitivity of the analysis of health related inequalities to how socioeconomic status is measured. Using data from Mozambique, the paper focuses on five key health service indicators, and tests whether measured inequality (concentration index) in health service utilization differs depending on the choice of welfare indicator. The paper shows that, at least in some contexts, the choice of welfare indicator can have a large and significant impact on measured inequality in utilization of health services. In consequence, we can reach very different conclusions about the 'same' issue depending on how we define socioeconomic status. The paper also provides some tentative conclusions about why and in what contexts health inequalities can be sensitive to the choice of living standards measure. The results call for more clarity and care in the analysis of health related inequalities, and for explicit recognition of the potential sensitivity of findings to the choice of welfare measure. The results also point at the need for more careful research on how different dimensions of SES are related, and on the pathways by which the respective different dimensions impact on health related variables.
TL;DR: There is much mobility in mental health from one wave to the next and the extent of mobility varies across socio-economic categories with greatest persistence observed in more disadvantaged groups.
Abstract: This paper is concerned with quantifying the level of mental health mobility in the British Household Panel Survey (BHPS). We investigate whether the extent of intertemporal fluctuations in mental health is different across categories of socio-economic group such as income quintiles, educational attainment and social class. Our measure of mental health is the 12-item version of the General Health Questionnaire (GHQ) that serves as a self-administered screening test aimed at detecting psychiatric disorders. Using 11 waves of the BHPS and a variety of methods we show there is much mobility in mental health from one wave to the next. Further the extent of mobility varies across socio-economic categories with greatest persistence observed in more disadvantaged groups. In general, these groups suffer poorer mental health and experience more periods of ill-health. Our results have implications for the design of appropriate prevention policies targeting mental illness within different risk groups, and also for the measurement of long-term inequalities in mental health across socioeconomic groups.
TL;DR: Using Spanish data from the National Health Survey of 1997, it is estimated that differences in insurance access is the main determinant of both, the choice of sector and the kind of physician contacted, giving rise to very different patterns of consumption of GP and specialist visits.
Abstract: This paper sheds light into the investigation of differential patterns of utilisation of physician services by populations subgroups that is emerging in a number of studies. Using Spanish data from the National Health Survey of 1997 we try to explain the distinct role of the type of insurance on the choice between specialists and GPs and its intertwining with the choice between private and public providers. We estimate a two-stages probit to conclude that differences in insurance access is the main determinant of both, the choice of sector and the kind of physician contacted, giving rise to very different patterns of consumption of GP and specialist visits. People with only public insurance go 2.8 times to the GP per one time that they visit a specialist; individuals with duplicate coverage have a ratio of GP/specialist visits equal to 1.4 (the combination being public GP and private specialist) and people with only private insurance access actually have an 'inverted' pattern of visits: they contact specialists more often than GPs. Age, sex and health and public supply characteristics also have a distinct and interesting impact on these choices. Finally, equity concerns based on the implied assumption that specialists care is superior to general practitioner care are discussed.