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[Methodolocical issues of naturalistic observational studies on the economic evaluation of neuroleptic treatment for schizophrenic disease].

Methodological problems of prospective natural trials are discussed. The application of adequate methods is demonstrated by analysing the effects of antipsychotic medical treatment on the probability and the costs of inpatient episodes of 307 patients with schizophrenia for 2.5 years. Selection bias is controlled by the propensity score method. Effects of medical treatment on the incidence of inpatient episodes are analysed by means of a random-effect logit model. Effects of medical treatment on the costs of inpatient episodes are analysed by means of a random-effect Tobit model. Results of the study show that antipsychotic medical treatment reduces the probability and the costs of inpatient treatment irrespective of the type of neuroleptic drugs. The hypothesis of a higher effectivity of atypical neuroleptics in comparison to conventional antipsychotics regarding the reduction of the incidence and the costs of inpatient treatment was not supported. Beyond the effects of medical treatment the study results indicate that improving social support and competence for coping with life events as well as providing community mental health services may reduce the risk and the costs of inpatient episodes.

Adolescent↗

[Efficiency of general practice in Switzerland].

BACKGROUND: In their capacity as gatekeepers, affect the entire cost of treatment of patients including cost for medication and inpatient care. Thus, it is of special interest to examine the production process of general practitioners. AIM: To study efficiency differences between general medical practices, taking into account a possible Managed Care participation by the physician. METHODS: A stochastic frontier analysis based on billing data of 1,500 Swiss physicians from 1997 - 1999 is applied to measure the relative efficiency of general practitioners. The number of consultations serves as output and the charged services as inputs of production. RESULTS: Most productive physicians are members of primary physicians' networks, in which the gate-keeping function of general practitioners is of central importance. For the "production" of one consultation they use 15 percent less resources than an average physician in a conventional medical practice. DISCUSSION AND CONCLUSION: In principle, assessment of efficiency of primary care physicians is possible. Differences in efficiency between physicians can be explained by characteristics of the individual medical practice. Disadvantages of the approach exist in the neglect of the patients' severity of illness and in having indirect measures of quality of medical care available.

Algorithms↗

Severity variations within DRGs: measurement of hospital effects by use of data on significant secondary diagnoses and procedures.

The Diagnosis Related Group classification has provided an excellent basis for enhancing the equity of resource allocation between public acute hospitals. However, it underestimates the higher levels of severity and consequent costliness of referral hospitals. This paper describes a practical way of measuring within-DRG variations in severity, which can be used to increase the precision of casemix-based funding. It involves the regression of length of stay against the numbers of significant diagnoses and procedures, and bence the prediction of additional justified costs. An example is given of its application to data from South Australian public hospitals.

Diagnosis-Related Groups↗

The differences between claim-based health risk adjustment models and cost prediction models.

There has been a significant increase in interest in using risk assessment tools with administrative claims data for provider profiling, provider payment, underwriting and disease/case management. The tools can be classified into two types: risk adjustment models and cost prediction models. The differences between the two models have not been well recognized. This paper explains the differences in terms of the objectives, the applications, and the accuracy of evaluations.

Insurance Claim Review↗

Accuracy of prediction models in the context of disease management.

There has been a significantly increased interest in the adoption of prediction modeling by many disease and case management programs to risk stratify members in order to optimize the utilization of available clinical resources. Before adopting any prediction model, it is critical to understand how to evaluate the model's accuracy. This paper explains the basic concepts of prediction accuracy, the relevant parameters, their drawbacks, and their interpretations. It also introduces a new accuracy parameter termed "cost concentration," which indicates the model accuracy more explicitly in the context of disease management.

Disease Management↗

Facility-level outcome performance measures for nursing homes.

Risk-adjusted nursing home performance scores were developed for four health outcomes and five quality indicators from resident-level longitudinal case-mix reimbursement data for Medicaid residents of more than 500 nursing homes in Massachusetts. Facility performance was measured by comparing actual resident outcomes with expected outcomes derived from quarterly predictions of resident-level econometric models over a 3-year period (1991-1994). Performance measures were tightly distributed among facilities in the state. The intercorrelations among the nine outcome performance measures were relatively low and not uniformly positive. Performance measures were not highly associated with various structural facility attributes. For most outcomes, longitudinal analyses revealed only modest correlations between a facility's performance score from one time period to the next. Relatively few facilities exhibited consistent superior or inferior performance over time. The findings have implications toward the practical use of facility outcome performance measures for quality assurance and reimbursement purposes in the near future.

Activities of Daily Living↗

Process-based costing.

Understanding how quality improvement affects costs is important. Unfortunately, low-cost, reliable ways of measuring direct costs are scarce. This article builds on the principles of process improvement to develop a costing strategy that meets both criteria. Process-based costing has 4 steps: developing a flowchart, estimating resource use, valuing resources, and calculating direct costs. To illustrate the technique, this article uses it to cost the care planning process in 3 long-term care facilities. We conclude that process-based costing is easy to implement; generates reliable, valid data; and allows nursing managers to assess the costs of new or modified processes.

Cost Allocation↗

Hours at work and employment status among HIV-infected patients.

OBJECTIVE: To study differences in employment and work hours among three groups of HIV-infected and non-infected individuals. METHODS: Data on 1263 patients seen in five different sites in California were drawn from the AIDS Time-Oriented Health Outcome Study. Three groups of patients were examined: AIDS patients, HIV-positives without diagnosed AIDS, and HIV-negatives. The HIV-negative patients were used as a comparison group in comparing hours worked by all patients, whether they worked or not; the probability of working, regardless of the number of hours; and work hours only for those patients who worked. RESULTS: Adjustment for covariates in a 2-equation econometric model reduced the difference in employment rates between the AIDS patients and the other two groups, suggesting that characteristics other than AIDS status account, in part, for their low employment rates. After adjustment, we did not find any statistically significant differences in employment probabilities or work hours between the HIV-positive patients without diagnosed AIDS and the comparison group. However, AIDS patients reported approximately 14 work hours fewer (P < 0.0001) and lower probabilities of employment (P < 0.0001) than the HIV-negative comparison group among all patients with and without jobs. Moreover, among those with jobs, patients with AIDS reported approximately 3 work hours fewer per week (P = 0.0385). No statistically significant differences in work hours were found between HIV-positives without diagnosed AIDS and comparison patients. CONCLUSION: AIDS patients were less likely to be employed than either of the other groups, but crude, unadjusted unemployment rates exaggerate the effect of AIDS. For those employed, AIDS patients work only 3 h less per week than either of the other groups.

Adult↗

Time trends in peptic ulcer disease and in gastritis and duodenitis. Mortality, utilization, and disability in the United States.

This study compared the results of two analytic methods testing the effects of histamine H2 receptor antagonists on acid-related conditions. We examined the rates of peptic ulcer disease-related and of gastritis- and duodenitis-related mortality, hospitalizations, surgery, physician visits, work-loss, and disability retirements in the United States from 1970 to 1986. First, we performed a nonparametric epidemiologic analysis. For mortality, hospitalizations, and surgeries, age-specific rates continued their historic decline; there was an additional large one-time decline of operations in 1978. Trends were stronger for peptic ulcer than for gastritis and duodenitis. From pooled annual data, rates of physician visits and physician referral declined for peptic ulcer and for gastritis and duodenitis in the post-1977 period (p = 0.0001). Work-loss and other restrictions on normal daily activities also declined for persons with peptic ulcer and with gastritis and duodenitis (p = 0.0001). Second, we fit a parametric model by maximum likelihood to test specific population effects of H2 blockers. The model indicated that people > or = 65 years old had increasing peptic ulcer mortality rates after 1977 (p < 0.001), while people < 65 years old had a deceleration in rates of decline (p < 0.01). Hospitalization rates for peptic ulcer and for gastritis and duodenitis increased in the elderly after 1977 (p < 0.01) and decreased among those < 65 years old. Both age groups experienced similar declining trends of operations for peptic ulcer; these were not significantly different when pre- and post-1977 periods were compared. The rate of disability retirement declined sharply for workers > or = 50 years old (p < 0.01) and for those < 50 years of age (p < 0.001). The inconclusive results of the parametric analysis, plus only partial congruence between parametric and nonparametric analyses, emphasize the difficulty of relating diverse effects over time to a single, new, more effective treatment.

Activities of Daily Living↗

Measuring hospital competition.

This paper appraises the use of the Herfindahl market share index as an exogenous competition variable in empirical studies of the hospital sector. An analysis of cross-sectional Florida data shows that this index itself is significantly influenced by the demand and supply factors commonly included in econometric models of hospital performance. The analysis then illustrates that biased inferences about the effects of market competition on the costs of hospital care may result unless the values of the Herfindahl Index are treated endogenously in hospital cost models.

Costs and Cost Analysis↗

Case-mix groups for VA hospital-based home care.

The purpose of this study is to group hospital-based home care (HBHC) patients homogeneously by their characteristics with respect to cost of care to develop alternative case mix methods for management and reimbursement (allocation) purposes. Six Veterans Affairs (VA) HBHC programs in Fiscal Year (FY) 1986 that maximized patient, program, and regional variation were selected, all of which agreed to participate. All HBHC patients active in each program on October 1, 1987, in addition to all new admissions through September 30, 1988 (FY88), comprised the sample of 874 unique patients. Statistical methods include the use of classification and regression trees (CART software: Statistical Software; Lafayette, CA), analysis of variance, and multiple linear regression techniques. The resulting algorithm is a three-factor model that explains 20% of the cost variance (R2 = 20%, with a cross validation R2 of 12%). Similar classifications such as the RUG-II, which is utilized for VA nursing home and intermediate care, the VA outpatient resource allocation model, and the RUG-HHC, utilized in some states for reimbursing home health care in the private sector, explained less of the cost variance and, therefore, are less adequate for VA home care resource allocation.

Aftercare↗

Methodological issues in linking costs and health outcomes in research on differing care delivery systems.

OBJECTIVES: This article discusses, from an economist's point of view, issues in designing and conducting research including cost and outcomes variables among differing care delivery systems. METHODS: Issues were identified, and selected research purporting to link cost and outcomes with variations in care delivery systems was reviewed. RESULTS: Current literature on nursing care delivery systems and costs in hospitals, ambulatory care, and nursing homes is focused mainly on group-specific costs linked to patient-specific outcomes. It suffers further from focusing primarily on single-discipline components of care, omitting the contributions of other providers beyond nursing personnel. CONCLUSIONS: Multidisciplinary teams, including economists who can speak clinical language, are recommended.

Ambulatory Care↗

Quality improvement as an investment.

Health care organizations are experiencing increasing internal and external pressures to improve the quality of care that they provide. However, there is not a framework that can be used to help understand the value of quality improvement projects and to prioritize competing projects. By understanding the current processes, costs and outcomes of care, enumerating the costs and benefits of change, anticipating the timing of the costs and benefits, and performing a financial analysis, quality improvement efforts can be evaluated as investments. Only by understanding and adapting to the financial environments in which health care organizations operate can continuous quality improvement in health care succeed.

Cost-Benefit Analysis↗

Critical care medicine as a distinct product line with substantial financial profitability: the role of business planning.

OBJECTIVE: As academic health centers face increasing financial pressures, they have adopted a more businesslike approach to planning, particularly for discrete "product" or clinical service lines. Since critical care typically has been viewed as a service provided by a hospital, and not a product line, business plans have not historically been developed to expand and promote critical care. The major focus when examining the finances of critical care has been cost reduction, not business development. We hypothesized that a critical care business plan can be developed and analyzed like other more typical product lines and that such a critical care product line can be profitable for an institution. DESIGN: In-depth analysis of critical care including business planning for critical care services. SETTING: Regional academic health center in southern New Jersey. SUBJECTS: None. INTERVENTIONS: As part of an overall business planning process directed by the Board of Trustees, the critical care product line was identified by isolating revenue, expenses, and profitability associated with critical care patients. MEASUREMENTS AND MAIN RESULTS: We were able to identify the major sources ("value chain") of critical care patients: the emergency room, patients who are admitted for other problems but spend time in a critical care unit, and patients transferred to our intensive care units from other hospitals. The greatest opportunity to expand the product line comes from increasing the referrals from other hospitals. A methodology was developed to identify the revenue and expenses associated with critical care, based on the analysis of past experience. With this model, we were able to demonstrate a positive contribution margin of dollar 7 million per year related to patients transferred to the institution primarily for critical care services. This can be seen as the profit related to the product line segment of critical care. There was an additional positive contribution margin of dollar 5.8 million attributed to the critical care portion of the hospital stay of patients admitted primarily through other product lines or the emergency room. This can be seen as the profit related to the "hospital service" segment of critical care. This represented a total contribution margin of dollar 12.8 million, approximately 24% of the institution's entire contribution margin. This information was subsequently used to develop strategic plans to promote this product line. CONCLUSIONS: We were able to define the critical care product line, and we were able to demonstrate profitability through an analysis of revenue and expenses related to critical care services. Our experience suggests that the concept of critical care as a product line, in addition to a hospital service, may lead to a useful analysis of this new discipline. This plan provided a rational foundation for development of the operating and capital budgets for the health system.

Academic Medical Centers↗

Adaptation and survivors in a random Boolean network.

We introduce the competitive agent with imitation strategy in a random Boolean network, in which the agent plays a competitive game that rewards those in minority. After a long time interval, the worst performer changes its strategy to the one of the best and the process is repeated. The network, initially in a chaotic state, evolves to an intermittent state and finally reaches a frozen state. Time series of survived species (whose strategies are imitated by other agents) in the system depend on the connectivity of each agent. In a system with various connectivity groups, the low connectivity groups win the minority game over the high connectivity groups. We also compared the result with mutation strategy system.

Adaptation, Psychological↗

Finite-size effect in the Eguíluz and Zimmermann model of herd formation and information transmission.

The Eguíluz and Zimmermann model of information transmission and herd formation in a financial market is studied analytically. Starting from a formal description on the rate of change of the system from one partition of agents in the system to another, a mean-field theory is systematically developed. The validity of the mean-field theory is carefully studied against fluctuations. When the number of agents N is sufficiently large and the probability of making a transaction a<<1/N ln N, finite-size effect is found to be significant. In this case, the system has a large probability of becoming a single cluster containing all the agents. For small clusters of agents, the cluster size distribution still obeys a power law but with a much reduced magnitude. The exponent is found to be modified to the value of -3 by the fluctuation effects from the value of -5/2 in the mean-field theory.

Cluster Analysis↗