Biomedical subjects

A Gafni

Publications and source records attributed to A Gafni.

At least 55 records · Page 3Linked to original sources

PubMed1999

Are health states "timeless"? The case of the standard gamble method.

The standard gamble method, as currently recommended for use in health care program evaluation, provides an individual's preference score or "utility weight" for living in a given health state for the rest of the individual's life. Many researchers interpret this value as a time-independent or "timeless" one and order health states on a scale of zero (death) to one (full health), regardless of the time spent in the health state. This article examines whether preference scores for a severe pain health state are "timeless," or in other words whether the utility independence assumption is satisfied. Our study results suggest that for the majority of respondents, the preference scores are not independent of time.

Aged↗

PubMed1999

The quick response initiative in the emergency department: who benefits?

OBJECTIVES: This collaborative project between two community hospitals, a Metropolitan Home Care Program and the University, was designed to quantify the applicability (who is eligible for) and acceptability (who will likely comply with) Home Care services, provided through a Quick Response Program (QRP) initiative as compared to usual hospital care services, to patients, families and physicians. METHODS: During a 6 week period of sampling (5 days per week, 8 hours per day) in two Emergency Departments (ED) in moderately sized community hospitals in a major metropolitan city, all patients triaged to the urgent category were assessed for eligibility for QRP services by on-site Home Care Coordinators using specific criteria. Patients meeting the criteria initially were reviewed by the ED physician for approval for QRP services and then randomized to experimental and control conditions. Patients not meeting the eligibility criteria were managed by the usual ED services procedures. Demographic and clinical data were obtained on all urgent category patients at presentation to the ED. Additionally, the nature and cost of all health care services used by the ED patients during the ED event and 10 days follow up, were obtained through hospital and Home Care record abstraction and compared among the different sample groups. RESULTS: The QRP Initiative was applicable to 2% of the total ED patient population and 5% of the urgent category of patients triaged in the ED. It was acceptable to 97% of this eligible group. One hundred and fifty-five patients who initially qualified for QRP were excluded from eligibility at a subsequent assessment. Ninety of these patients were admitted to hospital and 65 were discharged home. In the total "exclusion" group, 37 refused Home Care services including the QRP. HEALTH CARE PRACTICE IMPLICATIONS: The sampling results raise important questions about broader system issues concerning the role of the hospital and community in providing health care services and the social value or utility that guides the allocation of health care funds. What level of applicability and acceptability would justify priority services for certain target groups. In the future, policy makers will need to be able to show that it is in the best interest of patients and society to prioritize mixtures of services to certain target groups.

Adult↗

PubMed1999

Systematic validation of disease models for pharmacoeconomic evaluations. Swiss HIV Cohort Study.

Pharmacoeconomic evaluations are often based on computer models which simulate the course of disease with and without medical interventions. The purpose of this study is to propose and illustrate a rigorous approach for validating such disease models. For illustrative purposes, we applied this approach to a computer-based model we developed to mimic the history of HIV-infected subjects at the greatest risk for Mycobacterium avium complex (MAC) infection in Switzerland. The drugs included as a prophylactic intervention against MAC infection were azithromycin and clarithromycin. We used a homogenous Markov chain to describe the progression of an HIV-infected patient through six MAC-free states, one MAC state, and death. Probability estimates were extracted from the Swiss HIV Cohort Study database (1993-95) and randomized controlled trials. The model was validated testing for (1) technical validity (2) predictive validity (3) face validity and (4) modelling process validity. Sensitivity analysis and independent model implementation in DATA (PPS) and self-written Fortran 90 code (BAC) assured technical validity. Agreement between modelled and observed MAC incidence confirmed predictive validity. Modelled MAC prophylaxis at different starting conditions affirmed face validity. Published articles by other authors supported modelling process validity. The proposed validation procedure is a useful approach to improve the validity of the model.

AIDS-Related Opportunistic Infections↗

PubMed1999

Economic evaluations of community-based care: lessons from twelve studies in Ontario.

A series of 12 studies (five historic cohort and seven randomized trials) examined clients in community settings in Southern Ontario suffering from a variety of chronic physical and mental health conditions. These studies are appraised using a framework for evaluating possible outcomes of economic evaluation. In the 12 studies, sample composition and size varied. Each study was designed to quantify the well-being outcomes and expenditures associated with different community-based approaches to care provided in the context of a system of national health insurance. As a collective, these studies represent increasing methodological rigour. Multiple-perspective client well-being outcome measures were used. In two studies, caregiver burden also was analysed. A common approach to quantification and evaluation of expenditures for service consumption was used in all 12 studies. The nature of community-based health services (health vs. disease care orientation) was found to have direct and measurable impact on total expenditures for health service utilization and client well-being outcomes. In most cases, a recurring pattern of equal or better client outcomes, yet lower expenditures for use of community based health services, was associated with well-integrated health oriented services. Integrated services aimed at factors which determine health are superior when compared to individual, fragmented, disease oriented, and focused approaches to care. The main lessons from the 12 studies are that it is as or more effective and as or less expensive to offer complete, proactive, community health services to persons living with chronic circumstance than to provide focused, on-demand, piecemeal services. Complete services would have a psychosocial and mental health focus included with the physical care approach. Furthermore, people with coexisting risk factors (age, living arrangements, mental distress and problem-solving ability) are the ones who most benefit at lower expense from health oriented, proactive interventions.

Cohort Studies↗

PubMed1999

Cost-effectiveness of azithromycin for preventing Mycobacterium avium complex infection in HIV-positive patients in the era of highly active antiretroviral therapy. The Swiss HIV Cohort Study.

We conducted a cost-effectiveness analysis to determine the clinical and economic consequences of Mycobacterium avium complex (MAC) prophylaxis in HIV-infected patients in the era of highly active antiretroviral therapy (HAART) in a health care system with access unrestricted by financial barriers. The analysis was performed from a health care perspective and compared azithromycin (1200 mg/week) with no prophylaxis over a period of 10 years based on data from the Swiss HIV Cohort Study (SHCS) and randomized controlled trials. The main outcome measures were: expected survival; average health care costs; and cost-effectiveness in 1997 Swiss francs ( pound1 corresponds to about 2.3 CHF) per life-year saved. In patients with an initial CD4 count <50 cells/mm(3) and no AIDS, azithromycin increased expected survival by 4 months. In patients with AIDS, HAART durability had a major impact on expected survival and costs. Incremental survival increased from 2 to 4 months if we assumed a 10 year, instead of a 3 year, HAART effect. The cost-effectiveness of azithromycin relative to no prophylaxis in patients without AIDS was between 47,000 CHF (3-year HAART effect) and 60,000 CHF (10-year HAART effect) per life-year saved. The cost-effectiveness ratio increased to 118,000 CHF per life-year saved in patients with symptomatic AIDS. In conclusion, in the era of HAART, MAC prophylaxis with azithromycin increases expected survival and reduces health care costs substantially. Starting MAC prophylaxis in patients without AIDS is more effective and cost-effective than in patients with AIDS.

AIDS-Related Opportunistic Infections↗

PubMed1999

How to use the results of an economic evaluation.

BACKGROUND: Given the high costs of delivering care to critically ill patients, practitioners and policymakers are beginning to scrutinize the costs and outcomes associated with intensive care. Health economics is a discipline concerned with determining the best way of using resources to maximize the health of the community. This involves addressing questions such as which procedure, test, therapy, or program should be provided, and to whom, given available resources. PURPOSE: The purpose of this article is to review general economic principles that will help intensivists to better interpret published economic evaluations. DATA SOURCES: Selected articles from the health economics and critical care literature. RESULTS: In this article, we use an economic evaluation that examines sedation strategies in critically ill patients. We discuss how learning to critically appraise an economic evaluation is only part of the task for end users. Determining whether and how to apply the results of economic evaluations to local settings presents bigger challenges and remains largely a matter of judgment. CONCLUSIONS: Economic evaluations use analytic techniques to systematically consider all possible costs and consequences of clinical actions. Although they should never form the sole basis for clinical decisions for individual patients, economic evaluations offer potentially useful information at different levels of decision-making.

Cost-Benefit Analysis↗

PubMed1999

Demographic predictors of resource utilization for bleeding peptic ulcer disease: the Ontario GI Bleed Study.

Peptic ulcer disease (PUD) and its complications impose a substantial burden on health care resources. To help identify subpopulations in which preventative measures might achieve maximal cost savings, the authors studied the variation in resource utilization and cost for management of bleeding PUD among demographic subgroups. Resource utilization profiles and direct medical cost estimates were generated for consecutive admissions for bleeding PUD at four hospitals in southern Ontario via chart review and adaptation of an administrative cost database. Multiple linear regression models were developed to identify independent demographic predictors of direct medical case cost and hospital length of stay (LOS). Among 158 admissions, the average LOS and case costs were 5.73 days and $2,953 (Canadian) respectively. Age, comorbid illness, nonsteroidal anti-inflammatory drug use, and the absence of prior PUD or upper gastrointestinal hemorrhage were associated with higher cost in univariate analysis, whereas increasing age and comorbidity predicted LOS. Only age and absence of prior PUD persisted as independent predictors of direct medical cost and LOS in a stepwise multiple linear regression. Costs for managing bleeding PUD vary substantially among demographic subgroups. More careful stratification of treatment costs is needed when economic models of interventions to prevent or to treat PUD are applied to specific subpopulations.

Adult↗

PubMed1999

Community care for people with chronic conditions: an analysis of nine studies of health and social service utilization in Ontario.

A series of studies conducted in the same region found that programmatic, community-based health and social service interventions have a positive impact on client well-being. These proactive interventions, designed to address the full range of health and social needs, were usually provided at the same--or even lower--costs as uncoordinated, illness-focused care. The results of this series suggest that across-the-board health care reduction, at least in a system of national health insurance, will produce poorer results, at higher cost, for people with chronic conditions living in the community. Policy planners need more research that concentrates on comparisons of outcomes between and within different models of health and social service delivery. The studies should be designed to help them determine who benefits from different service configurations carried out within a range of policy environments at various costs.

Canada↗

PubMed1999

Prediction of resource utilization and case cost for acute nonvariceal upper gastrointestinal hemorrhage at a Canadian community hospital.

OBJECTIVE: Upper gastrointestinal hemorrhage (UGIH) is common, and thus imposes a substantial burden on health care resources. We describe resource utilization and cost for management of acute nonvariceal UGIH, and studied their variation among population subgroups. METHODS: Resource utilization and direct medical case costs were extracted for consecutive admissions for nonvariceal UGIH at a large community hospital in southern Ontario through chart review and adaptation of an administrative case cost database. Univariate and multiple regression models were then developed to identify independent demographic predictors of case cost and length of stay. RESULTS: Among 116 eligible admissions the average length of stay and case cost were 4.26 days and Can$2690, respectively (Can$1 = US$0.70). Both cost and length of stay demonstrated significant univariate relationships with age, comorbid illness, prior peptic ulcer disease (PUD), and prior UGIH. Age and prior PUD persisted as independent predictors in multiple regression models. An inverse transformation of total case cost allowed these variables to explain 26% of the total variance. CONCLUSIONS: Resource utilization for management of acute nonvariceal UGIH at a Canadian community hospital varies substantially among population subgroups, but correlates independently with age and prior ulcer history. Careful attention must be paid to practice environments and demographic profiles before economic models of strategies to prevent or treat UGIH are applied to specific subpopulations.

Acute Disease↗

PubMed1999

Willingness to pay for periodontal therapy: development and testing of an instrument.

OBJECTIVES: The objective of this study was to develop and test the feasibility and validity of a willingness to pay (WTP) tool in a dental setting. METHODS: A questionnaire measured individuals' preferences among alternative treatments for periodontal disease and the maximum they would be willing to pay for their treatment of choice in terms of dental insurance premiums. The questionnaire provides detailed information, in probabilistic terms, of the risks and benefits of treatment choices for moderate to advanced adult periodontitis. It was pilot tested on 23 periodontal patients and 18 dental school faculty and staff. RESULTS: The majority (92.6%) felt the questionnaire was an accurate representation of treatments and outcomes, establishing face and content validity. In terms of construct validity, four hypotheses were tested: (1) manipulation of the outcomes of the preferred treatment led to a predictable shift in preferences for 38 subjects (92.7%); (2) although periodontal patients were not more likely to choose periodontal surgery than nonpatients (P = .14), those with a history of surgery were more likely to choose surgery again (P = .06); (3) WTP was positively related to income level (P = .05); and (4) subjects were willing to pay more for coverage for themselves than for others. Periodontal surgery was the preferred treatment for moderate to advanced periodontal disease, and was more strongly preferred than other choices (i.e., a higher WTP) for all income groups. The intraclass correlation coefficient for treatment preferences was 0.95 (P < .001) and the kappa for WTP was 0.78 (P < .001). CONCLUSION: This pilot study supports some of the criteria concerning validity of the WTP questionnaire to measure preferences for alternative periodontal therapies. Further testing on larger samples is required to confirm these results.

Adult↗

PubMed1999

Mastectomy or lumpectomy? Helping women make informed choices.

PURPOSE: To develop an instrument to help clinicians inform their patients about surgical treatment options for the treatment of breast cancer and to evaluate the impact of the instrument on the clinical encounter. METHODS: We developed an instrument, called the Decision Board, to present information regarding the benefits and risks of breast-conserving therapy (lumpectomy plus radiation therapy) and mastectomy to women with early-stage breast cancer to enable them to express a preference for the type of surgery. Seven surgeons from different communities in Ontario administered the instrument to women with newly diagnosed clinical stage I or II breast cancer over an 18-month period. Patients and surgeons were interviewed regarding acceptability of the instrument. The rates of breast-conserving surgery performed by surgeons before and after the introduction of the instrument were compared. RESULTS: The Decision Board was administered to 175 patients; 98% reported that the Decision Board was easy to understand, and 81% indicated that it helped them make a decision. The average score on a true/false test of comprehension was 11.8 of 14 (84%) (range, 6 to 14). Surgeons found the Decision Board to be helpful in presenting information to patients in 91% of consultations. The rate of breast-conserving surgery decreased when the Decision Board was introduced (88% v 73%, P =.001) CONCLUSION: The Decision Board is a simple method to improve communication and facilitate shared decision making. It was well accepted by patients and surgeons and easily applied in the community.

Adult↗

PubMed1999

Hospital selection for unit cost estimates in multicentre economic evaluations. Does the choice of hospitals make a difference?

OBJECTIVE: The objectives of this study were (i) to develop a conceptual framework for selecting hospitals for unit cost estimates in national and international multicentre trials and (ii) to test the impact of alternative hospital selection on the cost results. DESIGN AND SETTING: Within the conceptual framework, the following considerations which can be used when selecting a sample of hospitals for unit cost estimates in multicentre trials were identified: the number of hospitals; the sampling method; and the desired level of geographical subanalysis. Results from a recently completed international multicentre trial were used to explore changes in cost results obtained by using alternative methods of selecting and stratifying hospitals for unit cost estimates. PATIENTS AND PARTICIPANTS: The study included 5041 women from 72 hospitals in 6 countries with prelabour rupture of the membranes at term. INTERVENTIONS: The women were randomly assigned to induction of labour with intravenous oxytocin, induction of labour with prostaglandin E2 gel, or expectant management for up to 4 days with labour induced if complications developed. MAIN OUTCOME MEASURES AND RESULTS: Across each of the 4 management strategies of the study, the method of selecting and stratifying hospitals resulted in a 30 to 55% difference between the lowest and highest median unit cost estimates. In some cases, the relative ranking of the least to most expensive strategy varied across methods of hospital selection. The statistical comparisons across strategies found that the method used had a substantial impact on the conclusions of the economic evaluation. CONCLUSIONS: Unit cost information should be collected from as many hospitals as possible. Multivariate hospital cost studies are needed to identify important cost drivers that will assist with hospital selection in the future.

Costs and Cost Analysis↗

PubMed1999

Willingness to pay and the valuation of programmes for the prevention and control of influenza.

In this paper, we consider the role of willingness to pay (WTP) as a method for measuring the impact of healthcare programmes on population well-being. Alternative methods of outcome valuation, such as quality-adjusted life-years (QALYs), measure values through individuals' willingness to trade off a particular commodity, future life. Moreover, the method of valuation fails to incorporate several dimensions of benefit relevant to measuring well-being that are particularly important in programmes aimed at the prevention and control of influenza. In contrast, WTP provides a broad method of valuation based on individuals' willingness to trade off a much wider range of commodities. In addition, WTP incorporates externalities and uncertainty within individual valuations. We show that the main limitations of the WTP approach are not avoided by adoption of the QALY approach.

Attitude to Health↗

PubMed1999

Understanding economic evaluations: a review of the knee arthroplasty literature.

The study reviewed the literature to appraise the quality, quantity, and type of economic evaluation as it pertains to the knee arthroplasty literature. A computerized bibliographic search of MEDLINE from 1966-1996 was conducted, revealing a total of 43,178 articles dealing with cost analysis, of which 1611 were orthopedic. Of the economic orthopedic studies, only 63 dealt with the topic of knee arthroplasty. These studies were retrieved, of which only 40 papers met the inclusion criteria. These 40 studies were evaluated for methodological soundness based on established economic principles. None of the 40 studies met the established criteria to form a comprehensive economic evaluation. These results indicate that the orthopedic literature is lacking in economically sound evaluations, and guidelines are offered to aid orthopedists in appraising and improving the quality of economic studies.

Arthroplasty, Replacement, Knee↗

PubMed1999

Preference based measurements in dentistry: a review of the literature and recommendations for research.

Clinical outcomes are used routinely in dental clinical practice to determine whether or not a patient has exhibited improvement following treatment. While these measures can be useful in comparing therapies in disease specific terms, they do not incorporate outcomes which may be of interest to patients. Preference based outcome measurements, on the other hand, take into account an individual's life style, overall well being and economic resources. There is a number of preference based measures available from the medical field, many of which have been adapted for use in a dental setting. This paper outlines the strengths and weaknesses of these preference based measures, using examples from the dental literature when available. Particular emphasis is placed on an economic tool known as contingent valuation or 'willingness to pay' as a potential technique in the measurement of dental preferences.

Decision Making↗

PubMed1998

Surviving social assistance: 12-month prevalence of depression in sole-support parents receiving social assistance.

BACKGROUND: Although it is generally recognized that poverty and depression can coexist among single parents receiving social assistance, there is insufficient research on this topic. The goals of this study therefore were to investigate the prevalence, correlates and health care expenditures associated with depression among sole-support parents receiving social assistance. METHODS: Sole-support parents who had applied for social assistance in 2 regions of southwestern Ontario were included in the study. Depression was diagnosed with the 1994 University of Michigan Composite International Diagnostic Interview short forms. RESULTS: The 12-month prevalence rate of depressive disorder among the parents interviewed was 45.4% (345/760). A total of 247 (32.5%) had major depressive disorder alone, 19 (2.5%) had dysthymia, and 79 (10.4%) had both major depressive disorder and dysthymia ("double depression"). Those with major depressive disorder, particularly double depression, had significantly higher rates of coexisting psychiatric disorder than those without depressive disorders. Parents with depression reported higher rates of developmental delay and behaviour problems in their children than parents without depression. Expenditures for health care services were higher for parents with depression and for their children than for parents without depressive disorder and their children. INTERPRETATION: Single parents receiving social assistance have high rates of depression. Such parents with depression also have higher rates of other psychiatric disorders and higher expenditures for health care services, and their children have higher rates of developmental delay and behaviour problems.

Adaptation, Psychological↗

PubMed1998

Health care contingent valuation studies: a review and classification of the literature.

PURPOSE: The contingent valuation method (CVM) is a survey-based approach for eliciting consumer's monetary valuations for programme benefits for use in cost-benefit analysis (CBA). We used the conceptual framework of O'Brien and Gafni (1996) to classify and critically appraise health care CVM studies. METHODS: Search of computerized health care and economic citation databases (e.g. MEDLINE, ECONLIT) and manual search for papers published between 1984 1996 reporting primary data valuing health programme benefits in monetary units by CVM using willingness-to-pay (WTP) or accept (WTA). We classified studies using both empirical (i.e. who was surveyed and how) and conceptual criteria (i.e. which measure of consumer utility was measured and why). RESULTS: 48 CVM studies were retrieved; the majority (42) undertook money valuation in the context of cost benefit analysis (CBA), with the remainder being pricing/demand studies. Among the 42 CBA studies, the consumer utility being measured (i.e. compensating (CV) vs. equivalent variation (EV) was explicitly stated in only three (7%) studies). WTP was measured in 95% of studies and WTA in 5%. By cross-tabulation, 42 (91%) studies were designed as WTP/CV, two (4%) were WTP/EV, two (4%) were WTA/CV and no studies used WTA/EV. Most studies were administered by mail (52%) with 38% being in-person interviews. Value elicitation techniques included open-ended questions (38%), payment cards (19%) discrete choice questions (26%) or bidding games (29%). Some form of construct validation tests, particularly associations between WTP and income, were done in 21 studies (50%). CONCLUSIONS: (i) The number of health care CVM studies is growing rapidly and the majority are done in the context of CBA; (ii) there is wide variation among health care CVM studies in terms of the types of questions being posed and the elicitation formats being used; (iii) classification and appraisal of the literature is difficult because reporting of methods and their relationship with the conceptual framework of CBA is poor; (iii) the applicability to health care of the CVM guidelines issued by the National Oceanic and Atmospheric Administration (NOAA) panel for environmental economics is unclear.

Attitude to Health↗

PubMed1998

The physician-patient encounter: the physician as a perfect agent for the patient versus the informed treatment decision-making model.

Assuming a goal of arriving at a treatment decision which is based on the physician's knowledge and the patient's preferences, we discuss the feasibility of implementing two treatment decision-making models: (1) the physician as a perfect agent for the patient, and (2) the informed treatment decision-making models. Both models fall under the rubric of agency models, however, the requirements from the physician and the patient are different. An important distinction between the two models is that in the former the patient delegates authority to her doctor to make medical decisions and thus the challenge is to encourage the physician to find out the patient's preferences. In the latter, the patient retains the authority to make medical decisions and the physician role is that of information transfer. The challenge here is to encourage the physician to transfer the knowledge in a clear and nonbiased way. We argue that the choice of model depends among other things on the ease of implementation (e.g., is it simpler to transfer patient's preferences to doctors or to transfer technical knowledge to patients?). Also the choice of treatment decision-making model is likely to have an impact on the type of incentives or regulations (i.e., contracts) needed to promote the chosen model. We show that in theory both models result in the same outcome. We argue that the approach of transferring information to the patient is easier (but not easy) and, hence, more feasible than transferring each patient's preferences to the physician in each medical encounter. We also argue that because better "technology" exists to transfer medical information to patients and time costs are involved in both tasks (i.e. transferring preferences or information), it is more feasible to design contracts to motivate physicians to transfer information to patients than to design contracts to motivate physicians to find out their patients' utility functions. We illustrate our arguments using a clinical example of the choice of adjuvant chemotherapy versus no adjuvant chemotherapy for women with early stage breast cancer. We also discuss issues relating to the current realities of clinical practice and their potential implications for the way that economists model physician-patient clinical encounters.

Breast Neoplasms↗