Alberto Holly

Risk adjustment in Switzerland

In Switzerland the new law on Health Insurance, effective since 1996, introduced pro competitive changes in the market of sickness funds. The legislator expected high mobility between sickness funds of both healthy and sick insured as open enrolment was introduced with the new law. That is why the risk adjustment scheme, that was already introduced 1993, was limited until 2005. However, consumer mobility remained low and risk selection strategies are still profitable, since risk-adjustment is based only on demographic variables. This paper describes risk adjustment, consumer mobility, risk selection activities of sickness funds and the impact of imperfect risk adjustment on the development of HMO and PPO models. The paper concludes with a description of the current political and scientific discussion in Switzerland.

Kuhn-Tucker, likelihood ratio and Wald tests for nonlinear models with inequality constraints on the parameters

Abstract This paper considers the problem of testing statistical hypothesis in nonlinear regression models with inequality constraints on the parameters. First, the Kuhn-Tucker test procedure is defined. Next, it is shown that the distribution of the Kuhn-Tucker, the likelihood ratio and the Wald test statistics converges to the same mixture of chi-square distributions under the null hypothesis. To illustrate these results two examples are considered: (1) the problem of testing that individual effects are missing in an error component model, and (2) the problem of testing equilibrium for a model of markets in disequilibrium.

A Saddlepoint Approximation to the Distribution of the k-Class Estimator of a Coefficient in a Simultaneous System

A new approximation based on the saddlepoint method of approximating integrals is derived for the probability density of the k-class estimator in the case of the equation with two endogenous variables. The two tails of the density are approximated by different functions, each of which bears a close relationship with the exact density in the same region of the distribution. Corresponding approximations are also derived for the distribution function and the method of derivation should be useful in other applications. Some brief numerical results are reported which illustrate the performance of the new approximation.

Some useful equivalence properties of Hausman's test

Abstract This paper describes in general terms situations in which apparently different expressions for Hausmans test statistic are actually either asymptotically equivalent or numerically equal. It also describes, in the most general possible way, cases where quadratic forms based on linear combinations of the constrained and unconstrained estimators of all the unknown parameters of a model are asymptotically equivalent to the classical test statistics. The theoretical results presented in this paper are illustrated with an example.

Exploring differences in healthcare utilization of prisoners in the Canton of Vaud, Switzerland.

Prison healthcare is an important public health concern given the increasing healthcare needs of a growing and aging prison population, which accumulates vulnerability factors and suffers from higher disease prevalence than the general population. This study identifies the key factors associated with outpatient general practitioner (GP), nursing or psychiatric healthcare utilization (HCU) within prisons. Cross-sectional data systematically collected by the prison medical staff were obtained for a sample of 1664 adult prisoners of the Canton of Vaud, Switzerland, for the year 2011. They contain detailed information on demographics (predisposing factors), diagnosed chronic somatic and psychiatric disorders (needs factors), as well as prison stay characteristics (contextual factors). For GP, nurse and psychiatric care, two-part regressions are used to model separately the probability and the volume of HCU. Predisposing factors are generally not associated with the probability to use healthcare services after controlling for needs factors. However, female inmates use higher volumes of care, and the volume of GP consultations increases with age. Chronic somatic and psychiatric conditions are the most important predictors of the probability of HCU, but associations with volumes differ in their magnitude and significance across disease groups. Infectious, musculoskeletal, nervous and circulatory diseases actively mobilize GP and nursing staff. Schizophrenia, illicit drug and pharmaceuticals abuse are strongly positively associated with psychiatric and nurse HCU. The occupancy rate displays positive associations among contextual factors. Prison healthcare systems face increasingly complex organizational, budgetary and ethical challenges. This study provides relevant insights into the HCU patterns of a marginalized and understudied population.

A random linear functional approach to efficiency bounds

Abstract This paper suggests a method for obtaining efficiency bounds in models containing either only infinite-dimensional parameters or both finite- and infinite-dimensional parameters (semiparametric models). The method is based on a theory of random linear functionals applied to the gradient of the log-likelihood functional and is illustrated by computing the lower bound for Coxs regression model.

Does Poor Childhood Health Explain Increased Health Care Utilisation and Payments in Middle and Old Age

Headlines: The long-lasting health care consequences of childhood conditions Data Association between childhood health and health care utilisation in adulthood Exploring mechanisms responsible for the association Does the association vary across Europe? Conclusion and policy relevance

The Effect of Nonmedical Factors on Variations in the Performance of Colonoscopy Among Different Health Care Settings

Background:Previous published studies have shown significant variations in colonoscopy performance, even when medical factors are taken into account. This study aimed to examine the role of nonmedical factors (ie, embodied in health care system design) as possible contributors to variations in colonoscopy performance. Methods:Patient data from a multicenter observational study conducted between 2000 and 2002 in 21 centers in 11 western countries were used. Variability was captured through 2 performance outcomes (diagnostic yield and colonoscopy withdrawal time), jointly studied as dependent variables, using a multilevel 2-equation system. Results:Results showed that open-access systems and high-volume colonoscopy centers were independently associated with a higher likelihood of detecting significant lesions and longer withdrawal durations. Fee for service (FFS) payment was associated with shorter withdrawal durations, and so had an indirect negative impact on the diagnostic yield. Teaching centers exhibited lower detection rates and longer withdrawal times. Conclusions:Our results suggest that gatekeeping colonoscopy is likely to miss patients with significant lesions and that developing specialized colonoscopy units is important to improve performance. Results also suggest that FFS may result in a lower quality of care in colonoscopy practice and highlight the fact that longer withdrawal times do not necessarily indicate higher quality in teaching centers.

The determinants of individual health care expenditures in prison: evidence from Switzerland

BackgroundPrison health systems are subject to increasing pressures given the specific health needs of a growing and aging prison population. Identifying the drivers of medical spending among incarcerated individuals is therefore key for health care governance in prisons. This study assesses the determinants of individual health care expenditures within the prisons of the canton of Vaud, a large region of Switzerland.MethodsWe use a unique dataset linking demographic and prison stay characteristics as well as objective measures of morbidity to detailed medical invoice data. We adopt a multivariate regression approach to model total, somatic and psychiatric outpatient health care expenditures.ResultsWe find that chronic infectious, musculoskeletal and skin diseases are strong predictors of total and somatic costs. Schizophrenia, neurotic and personality disorders as well as the abuse of illicit drugs and pharmaceuticals drive total and psychiatric costs. Furthermore, cumulating psychiatric and somatic comorbidities has an incremental effect on costs.ConclusionBy identifying the characteristics associated with health care expenditures in prison, this study constitutes a key step towards a more efficient use of medical resources in prison.

Old Age, Health and Long-term Care

This chapter reviews some important issues concerning ageing, health and long term care. It emphasises policy questions, major progress in understandings, remaining gaps in knowledge and main challenges. Also, it discusses the current state of play of European research infrastructures and networks, and what is required with regard to research infrastructures, methodological innovations, data and networks – as well as the consequences for research policy.