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Biomedical subjects

A Gafni

Publications and source records attributed to A Gafni.

At least 73 records · Page 4Linked to original sources
PubMed1998

Valuing outcomes in health care: a comparison of willingness to pay and quality-adjusted life-years.

Quality-adjusted life-years (QALYs) and willingness to pay (WTP) are two preference-based measures of health-related outcomes. In this article, we compare these two measures in eliciting individuals' preferences for health outcomes associated with shingles. To collect the necessary preference data, we administered computer-interactive interviews to a sample of 65- to 70-year-olds. We found no significant correlation between QALYs and WTP across individuals. We discuss our findings and argue that our results raise questions about whether QALYs and WTP are equivalent preference-based measures of health outcomes.

Aged↗
PubMed1998

Frequency and methodologic rigor of quality-of-life assessments in the critical care literature.

OBJECTIVES: To present a framework for describing/measuring quality of life (QOL) and health-related quality of life (HRQL), and to assess the frequency and methodologic rigor of QOL studies in the adult critical care literature. DATA SOURCES: Computerized bibliographic search of published research, manual search of key intensive care unit (ICU) journals, and citation review of relevant articles. STUDY SELECTION: We manually searched Critical Care Medicine, American Journal of Respiratory and Critical Care Medicine, and Intensive Care Medicine for the period January 1992 to July 1995 to assess the frequency of published QOL studies. Combined with a computerized bibliographic search, we found 64 studies that met our criteria that reported on patient-related outcomes (other than mortality) after hospital discharge. DATA EXTRACTION: We abstracted data on the nature of each study, the instruments used to measure QOL, and the methodologic rigor of the QOL assessments. We evaluated each study using criteria we developed to assess the validity of HRQL measurements. MEASUREMENTS AND MAIN RESULTS: In our manual search, we found 1,073 articles relevant to the practice of adult critical care. Of these, 19 (1.7%)/1073 included QOL measurements. Combined with our comprehensive search strategy, we found 64 papers that evaluated QOL in ICU patients. These papers dealt primarily with issues of: prognosis (32 [50%]), resource allocation (23 [36%]), and clinical prediction (9 [14%]). We found no randomized trials that included post-ICU QOL as an outcome. With respect to the validity of the HRQL assessments, 63/64 (98%) studies evaluated aspects of patients' lives that we considered important. Thirty-three (52%) studies were limited in scope to specific aspects of HRQL, and 31 (48%) studies covered broad areas of HRQL. In these 64 studies, there were 108 different instruments used. The reliability and validity of the instruments used were reported in 7 (6%) and 15 (14%) cases, respectively. For 81 (75%) instruments, the investigators either explained the results or used informative, qualitative descriptors whose interpretation was self-evident. Overall, three (5%) of the included studies met all four methodologic criteria to assess the validity of HRQL assessments. CONCLUSIONS: QOL assessments occur infrequently in the ICU literature and are of limited methodologic quality. More studies using valid and reliable instruments are necessary to document the long-term QOL of critically ill patients, especially those at risk of a "poor" outcome.

Adult↗
PubMed1998

Assessing the value of a new pharmaceutical. A feasibility study of contingent valuation in managed care.

OBJECTIVES: The authors assessed the feasibility and construct validity of the contingent valuation method for measuring the monetary value to healthy enrollees in a health maintenance organization of a new drug, filgrastim, as prophylaxis against febrile neutropenia after chemotherapy treatment for cancer. METHODS: A random sample of 220 enrollees from a closed-panel staff-model health maintenance organization who did not have cancer were interviewed. Chemotherapy, febrile neutropenia and filgrastim were described by video and decision board. Questions were asked in two different scenarios: (1) User-based: Assuming they were at the point of consumption and about to receive chemotherapy, what is the maximum they would be willing to pay to receive filgrastim? and (2) Insurance-based: Given they were at risk of cancer in the future, what is the maximum they would be willing to pay in additional monthly insurance premiums to add filgrastim to the plan? In a second insurance scenario where respondents were told that filgrastim was covered, what is the minimum reduction in premium that persons were willing to accept to relinquish coverage of the drug? A 2 x 2 factorial design was used to contrast two bidding algorithms to test for starting point bias and two 5-yearly prior risks of cancer, 1/200 versus 1/100. Main effects were tested by ANCOVA controlling for age, sex, health, and income. RESULTS: Demographics of experimental cells were similar. No evidence was found of significant starting point bias. For user-based questions, as expected, willingness-to-pay increases with febrile neutropenia risk reduction, but at a declining marginal rate. Despite careful presentation of information to respondents, willingness-to-pay for insurance was higher in the lower prior risk group. Consistent with previous contingent valuation studies, the authors of the present study found evidence that willingness-to-accept exceeds willingness-to-pay for coverage of the same benefit. CONCLUSIONS: An insurance-based contingent valuation study is feasible in a health maintenance organization. Construct validation evidence was encouraging, with the exception of the test for prior risk of cancer; however, this was a between-person contrast and may have been confounded by other factors.

Adult↗
PubMed1998

Is it 'worthwhile' to continue treating patients with a prolonged stay (>14 days) in the ICU? An economic evaluation.

OBJECTIVE: To compare the cost and consequences of a policy of continuing to care for patients with a prolonged stay in the ICU with a proposed policy of withdrawing support. DESIGN: Economic evaluation using data derived from a prospective cohort study. SETTING: Adult medical/surgical ICU in a tertiary care hospital. PATIENTS: Consecutive patients admitted to the ICU. INTERVENTION: None. MAIN OUTCOME MEASURES: We performed a cost-accounting analysis on each patient in the ICU and followed up patients until 12 months after admission to ICU and assessed components of quality of life in survivors. RESULTS: During the study period, 690 patients were admitted to the ICU. Only 61 (9%) patients remained in the ICU for > 14 days. For this group, the mean length of stay in the ICU was 24.5 (+/-11.7) days and duration in hospital was 57.9 (+/-56.9) days. At 12 months, 27 (44%) were alive. Overall, the mean quality of life score at 12 months did not differ between patients with a short or prolonged stay in the ICU. The average ICU cost per day per patient was $1,565 (Canadian) resulting in a total cost for the whole cohort of Can $1,917,382. Over the same time period, 58 patients had life support withdrawn. On average, patients survived another day in the ICU, 2 more days in hospital, and all patients ultimately died. When treatment was discontinued, the costs of treating this cohort was Can $156,465. The incremental cost-effectiveness ratio is Can $65,219 per life saved or Can $4,350 per life-year saved. CONCLUSIONS: A considerable proportion of patients with a prolonged length of stay in the ICU survive their critical illness. Furthermore, their long-term quality of life seems reasonable. Our data suggest that continuing treatment for patients with a prolonged ICU stay may represent an efficient use of hospital resources and should be considered in the context of local budgets.

Adult↗
PubMed1998

Willingness to pay. What's in a name?

Despite renewed enthusiasm for the use of willingness to pay (WTP) in healthcare applications, there are still a lot of objections, resentment and scepticism regarding the desirability and feasibility of this technique. Objections can be classified into different categories: e.g. theoretical, feasibility of measurement, misunderstanding of economic concepts and emotional. In this commentary, I have tried to explain the nature of the 'emotional' objections to the use of WTP. I argue that such objections are not helpful and distract attention from the proper scientific debates about the important topics of theoretical foundation for economic evaluations and feasibility of measurement of individuals' WTP. I believe that some of the emotional objections to WTP stem from perceptions about the relationship between the WTP measure and actual payment for health services. Hence, I discuss the use of the WTP methodology in 2 distinct contexts--cost-benefit analysis (CBA) and market research. Understanding the difference between these 2 most common areas of use will help alleviate objections based on emotions, allow us to use the technique where there seems to be no objections to its use (i.e. market research) and concentrate on the scientific debate where objections exist (i.e. the case of CBA).

Canada↗
PubMed1998

Comparison of the time-resolved absorption and phosphorescence from the tryptophan triplet state in proteins in solution.

Measurement of the room temperature Trp triplet state lifetime in proteins by time-resolved phosphorescence can provide valuable information on the structure and dynamics of proteins in solution. Our time-resolved absorption measurements on the long-lived states resulting from electronic excitation of the chromophore demonstrate the presence of more complex behavior than revealed by time-resolved phosphorescence. To provide additional insight into this behavior, a comparative study of time-resolved transient absorption and time-resolved phosphorescence of proteins in solution was carried out. The results show that the time evolution of the long-lived states observed through transient absorption often differs considerably from that observed in time-resolved phosphorescence. In some proteins, the presence of competing reactions complicates the interpretation of the transient absorption measurements (which may affect the phosphorescence yield). A more complete characterization of these processes will likely prove useful in the study of protein structure and dynamics in solution.

Alkaline Phosphatase↗
PubMed1998

Prospective care of elderly patients in family practice. Is screening effective?

OBJECTIVE: To evaluate cost and benefits of screening for and treating health and lifestyle risks among community-dwelling elderly. DESIGN: Randomized controlled trial. SETTING: Primary care. PARTICIPANTS: An opportunistic and prompted sample of 619 rostered elderly patients presenting for treatment who screened positive. INTERVENTIONS: One third (209) of experimental subjects had screening questionnaires placed in their charts with concerns highlighted for referrals. Two control groups received usual care. MAIN OUTCOME MEASURES: Yearly assessments of health service use and multidimensional functional capacity. RESULTS: Overall, screening and treatment of functionally active, elderly, middle-class people had no significant beneficial effect. Almost half of the experimental sample was ineligible because of treatment noncompliance. Generally ineligible subjects were older and more severely impaired. Subjects 75 years and older with risk factors showed improvement in daily living activities, and those living alone were found to have improved mental health and social functions (11% and 22%, respectively). CONCLUSIONS: Screening and treatment was ineffective in improving total functional capacity of all seniors 65 years and older. Elderly people 75 years and older, however, who were living alone or lonely did benefit from screening and treatment showing an improvement in daily activities, mental health scores, and social functions. This finding has implications for selective preventive health care spending for the elderly. A 2-year follow-up period could be too brief to detect long-term effects of early intervention with younger, middle-class seniors, especially those who are already functionally active.

Activities of Daily Living↗
PubMed1998

Health years equivalents as a measurement of preferences for dental interventions.

OBJECTIVE: To test the feasibility and importance of measuring preferences among treatment choices using Healthy Years Equivalents (HYE). DESIGN: Development of scenarios for alternative approaches to caries treatment. Completion of category rating and standard gamble questions elicited in personal interviews. SETTING: The provision of dental care to children in a public-funded dental health clinic. PARTICIPANTS: Random sample of the adult population of Hamilton, Ontario. MAIN OUTCOME MEASURES: The percentage of the sample unable to complete the interviews, time taken to perform interviews, ease of understanding of interviews, correlation between rank ordering and HYE scores. RESULTS: Ninety-six per cent of the sample were able to complete the HYE exercise. Inconsistencies between HYE scores and rank orders implying preference reversal occurred in 6% of those completing HYE scores for the two scenarios. The additional time taken by the HYE was of the order of 17 minutes but increased with the age of the subject. Where problems occurred, they were related to the method of measurement or the sensitivity of the chosen scale as opposed to additional requirements of the HYE. There was some evidence that HYEs and QALYs produced different scores even in the context of chronic constant health states. CONCLUSIONS: HYEs are a feasible and important practical method of measuring preferences among interventions. Alternative utility-based approaches, such as willingness to pay, may be required to detect differences in modest improvements in temporary health states.

Adult↗
PubMed1997

Induction of labour versus expectant management for prelabour rupture of the membranes at term: an economic evaluation. TERMPROM Study Group. Term Prelabour Rupture of the Membranes.

BACKGROUND: As the interval between rupture of the fetal membranes at term and delivery increases, so may the risk of fetal and maternal infection. Recently the TERMPROM (Term Prelabor Rupture of the Membranes) Study Group reported the results of a randomized controlled trial comparing 4 management strategies: induction with oxytocin (IwO), induction with prostaglandin (IwP), and expectant management and induction with either oxytocin (EM-O) or prostaglandin (EM-P) if complications developed. The study found no statistically significant differences in neonatal infection and cesarean section rates between any of the 4 groups. OBJECTIVE: To conduct an economic evaluation comparing the cost of (a) IwO and EM-O, (b) IwP and EM-P and (c) IwO and IwP. DESIGN: An economic analysis, conducted alongside the clinical trial, using a third-party payer perspective. Analysis included all treatment costs incurred for both the mother and the baby. Information on health care utilization and outcomes was collected for all study participants. Three countries (Canada, the United Kingdom and Australia), corresponding to the largest study recruitment, were chosen for calculation of unit costs. For each country, the base, low and high estimates of unit cost for each service item were generated. Intention-to-treat analysis. Extensive statistical and sensitivity analyses were performed. RESULTS: The median cost of IwO per patient was significantly lower statistically than that of EM-O and IwP. This result held in all 3 countries compared -$114 and -$46 in Canada, -113 Pounds and -63 Pounds in the UK, and -A$30 and -A$49 in Australia) and after an extensive sensitivity analysis. There was no statistically significant difference in median cost per patient between IwP and EM-P. CONCLUSION: Although the clinical results of the TERMPROM study did not find IwO to be preferable to the other treatment alternatives, the economic evaluation found it to be less costly. However, these cost differences, even though statistically significant, are not likely to be important in many countries. When this is the case, the authors recommend that women be offered a choice between management strategies.

Australia↗
PubMed1997

The supportive care needs of newly diagnosed cancer patients attending a regional cancer center.

BACKGROUND: The objective of this study was to examine the physical and emotional health status, self-perceived problems, and needs of newly diagnosed cancer patients to determine and plan supportive care strategies. METHODS: A cross-sectional survey of newly diagnosed cancer patients attending a regional cancer center during a 6-month period was performed. Patients with breast, colorectal, head and neck, lung, and prostate carcinoma as well as nonmelanoma of the skin were selected randomly. Patients were interviewed prior to their first appointment at the clinic. Physical health status was assessed using the Symptom Distress Scale, psychologic health status was assessed with the General Health Questionnaire (GHQ), day-to-day functioning with the Rapid Disability Scale, and social support with the modified Sarason's Social Support Scale. Perceived needs were assessed in a number of ways, including identification of patients' specific social concerns and informational needs, and by asking them to list their current problems or concerns. RESULTS: Of 156 eligible patients, 134 completed the interview. One hundred and twenty-nine patients (96%) reported current symptoms that included fatigue (66%), worried outlook (61%), difficulty sleeping (48%), and pain (42%). Forty-four patients (33%) were identified as psychologically distressed with a GHQ score of > or = 6. One hundred and fourteen patients (85%) had informational needs, 89 (66%) indicated > or = 1 social concerns, and 55 (41%) reported a need for assistance with day-to-day living. CONCLUSIONS: Patients with newly diagnosed cancer commonly report symptoms related to fatigue, pain, and psychologic distress. Other frequently reported issues relate to the need for information and social concerns regarding the patients' ability to take care of their home and maintain family and other relationships. Awareness of these issues is important for planning supportive care interventions for newly diagnosed cancer patients.

Aged↗
PubMed1997

Needle exchange programs: an economic evaluation of a local experience.

OBJECTIVE: To determine whether providing a needle exchange program to prevent HIV transmission among injection drug users would cost less than the health care consequences of not having such a program. DESIGN: Incidence outcome model to estimate the number of cases of HIV infection that this program would prevent over 5 years, assuming that the HIV incidence rate would be 2% with the program and 4% without it, and that an estimated 275 injection drug users would use the service over this time. SETTING: Hamilton, Ont. OUTCOME MEASURES: Estimated number of cases of HIV infection expected to be prevented with and without the program over 5 years; estimated lifetime health care costs of treating an AIDS patient. The indirect costs of AIDS to society (e.g., lost productivity and informal caregiving) were not included. Projected costs were adjusted (discounted) to reflect their present value. In a sensitivity analysis, 3 parameters were varied: the estimate of the HIV transmission rate if no needle exchange program were provided, the number of injection drug users participating in the program, and the discount rate. RESULTS: With very conservative estimates, it was predicted that the Hamilton needle exchange program will prevent 24 cases of HIV infection over 5 years, thereby providing cost savings of $1.3 million after the program costs are taken into account. This translates into a ratio of cost savings to costs of 4:1. The sensitivity analysis confirmed that these findings are robust. CONCLUSION: Needle exchange programs are an efficient use of financial resources.

Canada↗
PubMed1997

Treatment of proximal vein thrombosis with subcutaneous low-molecular-weight heparin vs intravenous heparin. An economic perspective.

BACKGROUND: Subcutaneous low-molecular-weight heparin is at least as effective and safe as classic intravenous heparin therapy for the treatment of proximal vein thrombosis. Anticoagulant monitoring is not required with low-molecular-weight heparin. OBJECTIVE: To perform an economic evaluation of these therapeutic approaches by comparing cost and effectiveness. PATIENTS AND METHODS: A randomized trial in 432 patients with proximal vein thrombosis that compared intravenous heparin and low-molecular-weight heparin with objective documentation of clinical outcomes provided the opportunity to perform an analysis of cost-effectiveness to rank these alternative therapies in terms of both their cost and effectiveness. The economic viewpoint of this analysis was that of a third-party payer (ie, a ministry of health in Canada or an insurance company in the United States). RESULTS: In the intravenous heparin-treated group, the cost incurred for 100 patients was $414,655 (Canadian dollars) or $375,836 (US dollars), with a frequency of objectively documented venous thromboembolism of 6.9%. In the low-molecular-weight heparin-treated group, the cost incurred for 100 patients was $399,403 (Canadian dollars) or $335,687 (US dollars), with a frequency of objectively documented venous thromboembolism of 2.8%, thus providing a cost saving of $15,252 (Canadian dollars) or $40,149 (US dollars). Multiple sensitivity analyses were performed, and these procedures did not alter the findings of the study. CONCLUSIONS: The findings indicate that low-molecular-weight heparin therapy is at least as effective and safe but less costly than intravenous heparin treatment. The potential for outpatient therapy in up to 37% of patients who are receiving low-molecular-weight heparin would substantially augment the cost saving.

Anticoagulants↗
PubMed1997

Subcutaneous low-molecular-weight heparin vs warfarin for prophylaxis of deep vein thrombosis after hip or knee implantation. An economic perspective.

BACKGROUND: Postoperative venous thrombosis and pulmonary embolism present a major clinical threat to patients undergoing total hip or knee arthroplasty. We performed an economic evaluation of warfarin sodium and subcutaneous low-molecular-weight heparin sodium prophylaxis comparing cost and effectiveness. METHODS: A consecutive series of 1436 patients who underwent hip or knee arthroplasty comparing these 2 regimens in a randomized trial with objective documentation of outcomes provided the opportunity to perform economic evaluations for Canada and the United States. RESULTS: Deep vein thrombosis was documented in 231 (37.4%) of 617 patients given warfarin and in 185 (31.4%) of 590 patients given low-molecular-weight heparin (P = .03). In Canada, warfarin and low-molecular-weight heparin (tinzaparin sodium) incurred costs per 100 patients of $11,598 and $9,197, respectively, providing a cost savings of $2,401 for the low-molecular-weight heparin group. The drug cost of low-molecular-weight heparin (tinzaparin) was $6 per day and for warfarin was $0.32 per day. Sensitivity analysis showed that low-molecular-weight heparin is more costly if drug costs are increased by 1.5-fold (ie, the cost of tinzaparin is increased from $6 per day to $8.82 per day or more). In the United States, the analysis was also not definitive; low-molecular-weight heparin was more costly than warfarin at drug costs of $15 and $2.01 per day, respectively. CONCLUSIONS: Our findings indicate that the decision to use low-molecular-weight heparin or warfarin prophylaxis in patients undergoing major joint replacement surgery is a finely tuned trade-off. Prophylaxis with low-molecular-weight heparin is equally or more effective than the more complex prophylaxis with warfarin. Major bleeding is uncommon but less frequent with warfarin use. The most significant parameters that influence the comparative cost-effectiveness are the cost of the drug, the cost of international normalized ratio monitoring, and the costs associated with major bleeding. The analysis also demonstrates that the results are health care system dependent (Canada vs US). In Canada, low-molecular-weight heparin (tinzaparin) is less costly because it avoids the need for international normalized ratio monitoring. In the United States, the drug cost for low-molecular-weight heparin will likely be the principal determinant of relative cost-effectiveness.

Adult↗
PubMed1997

Alternatives to the QALY measure for economic evaluations.

Economic analyses (i.e., analyses that are concerned primarily with questions of resource allocation) are becoming more common in health care in general and care of cancer patients in particular. The most commonly used measure for the valuation of outcome in such analyses is the QALY (quality-adjusted life-years), which combines qualitative (i.e., quality of life) and quantitative (i.e., survival) aspects of the outcome into one dimension. Using economics (i.e., the discipline) as the mode of thinking to help solve problems of resource allocation in health, this paper describes a framework to evaluate the appropriateness of use of a measure of outcome in the context of an economic evaluation. This framework will be used to critically appraise the use of the QALY measure and of two alternative measures, HYE (healthy years equivalent) and WTP (willingness to pay), in economic evaluations of health care interventions. The paper also describes a practical tool that can be used to measure individuals' WTP in the context of public decision making. This tool involves modifying the decision board, a tool develop (originally in the cancer area) to help clinicians present information to patients. The intent is to show that the use of a theoretically superior measure of outcome need not always be empirically restrictive.

Algorithms↗
PubMed1997

Time-resolved room temperature tryptophan phosphorescence in proteins.

The application of luminescence, primarily fluorescence, to the study of protein structure and dynamics has been extensively exploited to facilitate the understanding of complex biological problems. The interest in the application of phosphorescence, however, shows that new and complementary information can be had by careful optical studies of the phosphorescence lifetime. As in the early days of fluorescence spectroscopy in proteins, a complete and rigorous interpretation of the room temperature phosphorescence remains to be developed; nevertheless, it is clear that time-resolved phosphorescence yields new information on proteins in solution, for example, the detection of subtle conformational changes during protein folding, which is outside the sensitivity of earlier techniques. In addition, the great sensitivity of the phosphorescence lifetime to structural changes associated with rigidity and of nearby quenchers suggests that detailed structural information can be obtained when this approach is combined with the power of site-directed mutagenesis or other more biophysical techniques such as energy transfer to attached acceptors. We have presented basic aspects of time-resolved room temperature phosphorescence spectroscopy and demonstrated some useful features of the spectroscopic signals as well as the general approach to data analysis. However, it should be understood that extensions of this approach will easily allow faster and improved time resolution with greater sensitivity to highly quenched phosphorescing states. In addition, many extensions of this approach that are common to fluorescence spectroscopy have yet to be developed. For example, combining time-resolved phosphorescence with anaerobic stopped-flow techniques and more rapid data acquisition electronics will enable studies of conformational dynamics with considerably shortened dead times. Other possibilities include extending the preliminary studies of in vivo-based spectroscopy, such as to microscopy. In conclusion, time-resolved phosphorescence presents a new dimension to biophysical methodologies for the study of proteins, and it is likely that this area will continue to grow in capability as the fundamental understanding improves.

Animals↗
PubMed1997

Shared decision-making in the medical encounter: what does it mean? (or it takes at least two to tango).

Shared decision-making is increasingly advocated as an ideal model of treatment decision-making in the medical encounter. To date, the concept has been rather poorly and loosely defined. This paper attempts to provide greater conceptual clarity about shared treatment decision-making, identify some key characteristics of this model, and discuss measurement issues. The particular decision-making context that we focus on is potentially life threatening illnesses, where there are important decisions to be made at key points in the disease process, and several treatment options exist with different possible outcomes and substantial uncertainty. We suggest as key characteristics of shared decision-making (1) that at least two participants-physician and patient be involved; (2) that both parties share information; (3) that both parties take steps to build a consensus about the preferred treatment; and (4) that an agreement is reached on the treatment to implement. Some challenges to measuring shared decision-making are discussed as well as potential benefits of a shared decision-making model for both physicians and patients.

Decision Making↗