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Biomedical subjects

A Gafni

Publications and source records attributed to A Gafni.

At least 91 records · Page 5Linked to original sources
PubMed1997

Age, adjustment, and costs: a study of chronic illnesses.

Much concern has been expressed about increasing health costs associated with an aging population. In relation to chronic conditions, this study demonstrates that cost seems to be a function of adjustment to the chronic condition rather than of age in and of itself. We know from previous work that people with poor psychosocial adjustment cost considerably more than do people who are either moderately or well adjusted and this study shows that older, poorly adjusted persons are no more costly than their younger counterparts.

Activities of Daily Living↗
PubMed1997

Immediate surgery versus waiting list policy in revision total hip arthroplasty. An economic evaluation.

An economic evaluation was carried out using a decision tree that models the costs and consequences of surgery at the point of consultation versus a waiting list policy for candidates in need of revision hip arthroplasty. The theoretical scenarios looked at a 2-year period wherein the immediate surgery patients incurred costs for 2 years after surgery, whereas the waiting list patients incurred costs for 1 year before and 1 year after surgery. Outcome probabilities were defined and applied to each treatment group, as derived from the literature and expert opinion. Expenditures were derived from the literature, based on conservative estimates of predicted pre- and postsurgical behavior for each scenario. This analysis indicates the potential for both substantial savings in resources and improved patient outcome for immediate surgery over waiting lists. These savings would begin at the inception of the immediate surgery protocol. Sensitivity analysis indicates that the conclusion is valid over a wide range of expenditures and probabilities.

Cost Savings↗
PubMed1997

The stable, inactive but reactivatable, unfolding intermediate of rat muscle sarcoplasmic reticulum Ca(2+)-ATPase differs from the age-modified form of this protein.

Ca(2+)-ATPase from rat skeletal-muscle sarcoplasmic-reticulum has been reported to be less stable in old animals. These changes were suggested to be due to age-related modifications in the membrane. In the present study, the guanidinium-chloride (GuHCl)-induced inactivation, and reactivation by dilution of the denaturant, of this enzyme have been investigated. The cooperativity of the inactivation-transition was found to increase when the membrane was dissolved in the non-ionic detergent polyoxyethylene 10 laurylether. There is an inactive unfolding intermediate in equilibrium with the native state at low concentrations of GuHCl. This intermediate can be reactivated, even after as long a time as 19 h. The stability of this intermediate is only slightly affected by detergent solubilization of the enzyme. Hence, the membrane probably only plays a minor role in stabilizing the intermediate.

Aging↗
PubMed1997

The efficacy and effectiveness of process consultation in improving staff morale and absenteeism.

OBJECTIVES: The purpose of this randomized controlled trial was to test the efficacy and effectiveness of process consultation consisting of a series of nurse manager-consultant problem-solving meetings for leadership development that would lead to their staff's improved morale, quality of care, and reduced absenteeism. METHODS: Thirteen consenting clinical inpatient units were stratified for four variables known to affect outcome and were then randomly assigned to treatment and control conditions. The nurse managers from the seven experimental units were paired with outside nurse consultants from the McMaster University School of Nursing (Hamilton, Ontario, Canada) in a cooperative form of retraining in problem-solving through process consultation. Morale was determined through measures of perceptions of the work environment, an attitude scale concerning work (alienation), a personality measure (hardiness), and one of each scale for work satisfaction and for sources of satisfaction and dissatisfaction. Demographic data and information regarding family life responsibilities were collected as well. Assessment of quality of care was determined by the frequency and type of incident reports and by patients' perception of their satisfaction. A ratio of absence hours to total paid hours of work was used to compare experimental and control units' absenteeism rates. RESULTS: Experimental subjects reported a statistically significant improvement in the characteristics of their work setting and in the quality of working relationships. The consultation process facilitated a perceived change in the organizational context of the experimental hospital units with less centralization of authority and more clarity about expectation. These organizational changes were accompanied by improved working relationships and less alienation from work. There was no statistically significant difference in absenteeism. However, a subanalysis of the units by "dose" of the intervention identified those who benefited from the effects of the consultation. Subjects whose nurse managers participated more actively in the consultation process accounted for the changes in working relationships and perceived organizational changes. The "low-dose" experimental subjects were more like the control subjects, with the exception of absenteeism, for which they had higher rates. CONCLUSIONS: The findings of this study suggest that process consultation can alter the staff's perceptions of the characteristics of the work setting, can reverse negative attitudes (alienation), and can create a more positive and supportive working environment (improved working relationship). However, the results suggest the need to target this type of intervention to managers who have the personal resources to engage in self-evaluation and personal development and thus to participate in the consultative process.

Absenteeism↗
PubMed1997

Economic and policy implications of adopting paclitaxel as first-line therapy for advanced ovarian cancer: an Ontario perspective.

PURPOSE: To determine the potential economic and policy implications that result from incorporating paclitaxel into first-line therapy for stage 3 and 4 ovarian cancer patients in the province of Ontario, Canada. METHODS: A cost-effectiveness analysis was conducted to compare cisplatin/cyclophosphamide (CC), a standard therapy, with cisplatin/paclitaxel (CT). Based on survival curves from a clinical trial, mean costs and survival were calculated. Sensitivity analyses were conducted based on altering the duration of paclitaxel infusion, discount rates, and efficacy of paclitaxel. RESULTS: The mean survival duration is prolonged from 2.06 years with the standard therapy to 2.44 years with the paclitaxel combination. The paclitaxel therapy is more expensive, with a mean cost of $17,469 (Canadian) per patient treated with CT compared with $5,228 per patient with CC. The incremental cost-effectiveness ratio is $32,213 per year gained. Sensitivity analyses show that the conclusions remain unchanged. The use of CT as first-line treatment for advanced ovarian cancer patients in Ontario requires an additional $9 million per year over and above the present costs to treat this patient population. CONCLUSION: Although paclitaxel-based therapy prolongs survival, it comes at an increased cost. It may not be possible to fund paclitaxel treatment using resources presently allocated to first-line chemotherapy for advanced ovarian cancer. The policy implications for absorbing the cost of paclitaxel in the context of a publicly funded health care system are discussed.

Antineoplastic Agents, Phytogenic↗
PubMed1997

Willingness to pay in the context of an economic evaluation of healthcare programs: theory and practice.

Cost-benefit analysis (CBA) is defined in the methodology literature as a form of economic evaluation in which both costs and consequences are measured in monetary terms. In recent years we have witnessed renewed enthusiasm for CBA and the use of willingness to pay (WTP) as a method of measuring benefits from healthcare providers. Using the economics perspective, this paper assesses the usefulness of the WTP measure in a context of CBA analysis for economic evaluation of healthcare interventions. Starting from the welfarist approach as the foundation of the analysis, this paper evaluates the benefit and cost of using WTP as a measure of outcome compared mainly with the most commonly used measure of outcome (i.e., quality-adjusted life years) as well as a newly suggested measure of outcome (i.e., healthy-years equivalents). This paper studies this issue from both theoretical and practical aspects. The analysis starts with the premise that we want to use the discipline of economics as the mode of thinking and evaluate the methods suggested using economic criteria. A framework that includes five indicators (or criteria) to help identify the measures of outcome that are proper for use in the context of an economic evaluation are described. Following this framework, the paper argues that from a theoretic perspective the WTP approach is the best available measure, despite its limitations. This paper also describes a new instrument that can be used to measure individuals' WTP as well as a recent experience assessing the feasibility of using such an instrument in the context of evaluating a new pharmaceutical agent in a managed care setting. The conclusion of this study is that this technique holds promise as a method that can generate monetary values for program benefits for future use in CBA.

Cost-Benefit Analysis↗
PubMed1996

A review and economic evaluation of bronchodilator delivery methods in hospitalized patients.

BACKGROUND: Bronchodilator delivery by metered dose inhaler (MDI) to treat airflow obstruction is considered to be less expensive and as effective as nebulized therapy. OBJECTIVES: To document the utilization of bronchodilator delivery methods in a tertiary care Canadian university teaching hospital and to perform an economic evaluation. METHODS: A prospective 6-week audit of 4 preselected hospital wards (respiratory, thoracic surgery, general surgery, and a general internal medicine clinical teaching unit) and a cost-minimization economic evaluation were performed. Bronchodilator (salbutamol and ipratropium bromide) doses, frequency, and delivery methods, either MDI or wet nebulizer (WN), were recorded for 95 patients treated with aerosolized bronchodilators. Direct costs for medications and hourly wages including benefits and equipment were obtained. Time and motion studies identified time allocated to MDI and WN delivery. We used sensitivity analyses to test assumptions that could significantly affect treatment costs, especially assumptions about medications, labor, and spacer devices. Costs are expressed in Canadian dollars (Can$1 = US$0.75). RESULTS: Sixty-seven patients (70.5%) were treated with WN, 6 (6.3%) with MDI, and 22 (23.2%) with both WN and MDI. Self-administration of salbutamol by MDI was the least expensive: $1.27 for 200-microgram doses and $1.73 for 400-microgram doses compared with $2.62 for a 2.5-mg dose delivered by WN. The difference in cost between equivalent treatments (400-microgram MDI vs 2.5-mg WN) is only $0.89. Sensitivity analyses showed that MDI was the least expensive therapy when self-administration was possible and for all levels of supervision if more than 4 minutes was needed to administer a WN treatment. CONCLUSIONS: Bronchodilator delivery by WN is commonly prescribed for hospitalized patients despite evidence for equivalency of effect using MDI and in the absence of substitution protocols. Previous studies have estimated a far greater cost differential based on unrealistic labor estimates. We found that supervision of patients using MDIs minimized the differential cost between WN and MDI therapy and that cost savings are maximal in patients who can self-administer MDI therapy. Methodologically sound economic evaluations can better identify true cost savings and variables that need further study.

Adolescent↗
PubMed1996

Long time-scale probing of the protein globular core using hydrogen-exchange and room temperature phosphorescence.

Preliminary room temperature phosphorescence measurements of the highly buried Trp109 in E. coli alkaline phosphatase have been used to report on the kinetics of protein hydrogen-deuterium exchange. Upon dilution in D2O the phosphorescence lifetime increases (at 20 degrees C) in a biphasic manner with an immediate change (< 30 seconds) followed by a slow change occurring on an extremely long timescale (days). The immediate D2O-induced lifetime increase is similar to that observed upon dilution into glycerol, a known protein hydrating agent. On the other hand, the slow D2O-induced first order growth in Trp109 lifetime is due to exchange at highly protected protein groups. As the phosphorescence lifetime of Trp109 is dependent on local rigidity, this increase in lifetime reflects changes in alkaline phosphatase structure. This first use of room temperature phosphorescence to monitor proton exchange shows promise as a sensitive and selective probe of protein core dynamics.

Alkaline Phosphatase↗
PubMed1996

In vitro renaturation of bovine beta-lactoglobulin A leads to a biologically active but incompletely refolded state.

When bovine beta-lactoglobulin (beta-LG) was refolded after extensive denaturation in 4.8 M guanidine hydrochloride (GuHCl), the functional activity of the protein, retinol binding, as measured by the enhancement of this ligand's fluorescence, was completely recovered. In contrast, the room-temperature tryptophan phosphorescence lifetime of the refolded protein, a local measure of the residue environment, was approximately 10 ms, significantly shorter than the phosphorescence lifetime of the untreated native protein (approximately 20 ms). The lability of the freshly refolded protein, as monitored by following the time course of its unfolding when incubated in 2.5 M GuHCl through the change in fluorescence intensity at 385 nm, was also determined and found to be increased significantly relative to untreated native protein. In contrast to the long term postactivation conformational changes detected previously in Escherichia coli alkaline phosphatase (Subramaniam V, Bergenhem NCH, Gafni A, Steel DG, 1995, Biochemistry 34:1133-1136), we found no changes in either the lability or phosphorescence decays of beta-LG during a period of 24 h. Our results are in agreement with the report by Hattori et al. (1993, J Biol Chem 268:22414-22419), using conformation-specific monoclonal antibodies to recognize native-like structure, that long-term changes occur in the protein conformation, compared with the native structure, on refolding.

Animals↗
PubMed1996

Patients' preferences for therapy in advanced epithelial ovarian cancer: development, testing, and application of a bedside decision instrument.

The objective of this study was to determine a patient's preference for treatment in the poor prognostic situation of advanced epithelial ovarian cancer. A standardized method of information transfer was developed and pretested for feasibility, acceptability, comprehension, interobserver reliability, and validity. The Decision Board (DB) describes to the patient who has completed surgery for suboptimally debulked ovarian cancer two treatment options, their potential side effects, and possible outcomes. The psychometric properties of the DB were determined in 37 volunteers without cancer and 11 women following first-line chemotherapy for ovarian cancer. The Board was then administered to 12 patients with stage IIIc and IV ovarian cancer at the point of deciding future chemotherapy. The feasibility of presenting poor prognostic information, patient comprehension in an emotionally charged situation, and her treatment choice were determined. Observation of patient-physician interviews revealed that survival information is not usually discussed on the initial consultation. Using the DB, it was feasible to provide survival information to 98% of the healthy women. Comprehension was high, with 96% of the questions being correctly answered. Interobserver reliability was high (kappa = 1.00). The construct that hypothesized that understanding information is a determinant of choice was verified, as 95.2% of women had predictable shifts in expressed preference. The strength of preference in healthy women was statistically significantly higher for Plan B (paclitaxel-cisplatin) than for Plan A (cisplatin-cyclophosphamide) (P < 0.001). The method of presenting survival information (median survival versus percentage survival at 3.5 years) influenced choice (P < 0.04). At the point of decision making, 33% of patients with advanced ovarian cancer chose Plan A and 67% chose Plan B. All volunteers and patients stated that they wanted to be fully informed of the choices of therapy for their disease and to be involved in treatment decisions. The DB is a reliable and valid method for sharing information about advanced ovarian cancer with patients. At the point of deciding first-line chemotherapy in this poor prognostic situation, patients still value survival more highly than the quality of life during chemotherapy.

Adult↗
PubMed1996

Time preference, the discounted utility model and health.

The constant rate discounted utility model is commonly used to represent intertemporal preferences in health care program evaluations. This paper examines the appropriateness of this model, and argues that the model fails both normatively and descriptively as a representation of individual intertemporal preferences for health outcomes. Variable rate discounted utility models are more flexible, but still require restrictive assumptions and may lead to dynamically inconsistent behaviour. The paper concludes by considering two ways of incorporating individual intertemporal preferences in health care program evaluations that allow for complementarity of health outcomes in different time periods.

Decision Support Techniques↗
PubMed1996

Detection of a pH-dependent conformational change in azurin by time-resolved phosphorescence.

Azurin, a blue copper protein from the bacterial species Pseudomonas aeruginosa, contains a single tryptophan residue. Previous fluorescence measurements indicate that this residue is highly constrained and unusually inaccessible to water. In the apoprotein this residue also possesses a long-lived room-temperature phosphorescence (RTP), the nonexponential decay of which can be resolved into two major components associated with lifetimes of 417 and 592 ms, which likely originate from at least two conformations of the protein. The relative weights of these two decay components change with pH in good correlation with a change in protonation of His-35, which has been studied in Cu(II) azurin. Interestingly, the structural changes characterized in earlier work have little effect on the fluorescence decay and appear to occur away from the tryptophan residue. However, in the present work, the two RTP lifetimes suggest conformations with different structural rigidities in the vicinity of the tryptophan residue. The active conformation that predominates below a pH of 5.6 has the shorter lifetime and is less rigid. Phosphorescence decays of several metal derivatives of azurin were also measured and revealed strong similarities to that of apoazurin, indicating that the structural constraints upon the metal-binding site are imposed predominately by the protein.

Apoproteins↗
PubMed1996

Improved differentiation between luminescence decay components by use of time-resolved optical activity measurements and selective lifetime modulation.

The analysis of luminescence decay experiments from proteins is typically modeled as a combination of independent first-order decay functions. However, Poisson noise in the photon counting experiment limits the ability of this approach to resolve decay components from separate lumiphores with similar lifetimes. To provide further differentiation, we incorporate time-resolved circular polarization of luminescence, an additional independent observable, into the analysis. In the simplest case, for example, each lumiphore's chirality is assumed to be time independent and is determined by the position of the lumiphore with respect to the surrounding chiral environment within the protein. In this paper, we describe the analysis of simultaneously recorded time-resolved luminescence and circularly polarized luminescence data to obtain improved temporal resolution. When combined with selective dynamic luminescence quenching, in a model system comprising a mixture of Tb/transferrin and Tb/conalbumin, we demonstrate resolution between two decay components with a lifetime difference of 7% and a difference in emission anisotropy of 5 X 10(-2). Evidence for the improved discrimination is further demonstrated by the increase in curvature of the chi 2 surface that results from the additional information.

Animals↗
PubMed1996

A randomised trial of two information packages distributed to new cancer patients before their initial appointment at a regional cancer centre.

The purpose of this study was to evaluate the extent to which a new patient information package (NPIP) or a mini version of the same package (mini-NPIP) reduces emotional distress and meets the informational needs of patients arriving at a tertiary cancer centre for the first time. A comprehensive package, NPIP, consisting of procedural information regarding cancer centre location, description of the health care team, treatment services, research, educational activities, accommodation and community services provided at the centre; and a condensed version of the same package, mini-NPIP, were developed. Consecutive patients with newly diagnosed breast, gynaecological, lung and prostate cancer, referred to the centre for the first time were prerandomised to receive NPIP, mini-NPIP or no information package. Patients randomised to NPIP or mini-NPIP were mailed the information package at least one week before their first appointment. On arrival at the centre, patients were administered the Brief Symptom Inventory (BSI) which measures psychological distress, and interviewed regarding preferences for information and acceptability of the information packages. Of 465 randomised patients, 161 were excluded post-randomisation and 304 completed the entire interview: 100 were randomised to the NPIP, 102 to the mini-NPIP and 102 to the control group. Emotional distress as measured by the BSI was similar for all groups (P = 0.98). Most patients preferred to receive the information (98%), receive it before the first appointment (84%) and by mail (79%). These preferences were more evident for those given the information packages. The majority of patients found the information packages easy to understand (88%) and useful (89%), and no differences were detected between packages. The cost of production and dissemination of NPIP was more than double the cost for mini-NPIP: $ 8.93 vs $ 3.98 (Canadian dollars) per patient. For patients presenting to a cancer centre for the first time, packages of procedural information do not appear to reduce psychological distress, but are preferred by patients. Given the cost of producing NPIP, mini-NPIP is the preferred approach.

Feasibility Studies↗
PubMed1996

Gender differences in psychosocial adjustment to chronic pain and expenditures for health care services used.

Gender differences in reports of chronic pain, in coping responses to the consequences of painful conditions, and in the use of health care services have recently received considerable attention. This report examines the gender effects of referral practices to a chronic pain specialty clinic and the nature of the relationship between health care needs and use of health care services. This historical cohort analytic survey of 571 patients referred to the pain clinic assessed them by gender for selected referral variables through a chart review, and randomly sampled (n = 222) these patients' current adjustment and health service use through mailed questionnaires or telephone interview. The questionnaire consisted of psychosocial scales (PAIS-SR; Social Support); cognitions, including the Meaning of Illness Questionnaire (MIQ); and a health service utilization inventory designed to assess direct, out-of-pocket, indirect, and cash transfer expenditures. Selected referral demographic characteristics were similar between the gender groups at referral with the exception of three factors: distance from clinic, referring physician, and having a disability pension. At follow-up, the adjustment groups were similar to their gender counterparts on all sociodemographic and clinical variables including a high prevalence of poor psychosocial adjustment. Women's adjustment was accounted for by cognitive variables, whereas men's adjustment was by social variables. There were differential expenditures for health service use by gender with similar health care needs. Women used specific health care services more than men, which was explained in part by psychological need and meaning. Men's use of services, on the other hand, was explained in part by meaning alone. The importance of gender, differences in the role that social support and meaning variables play in predicting psychosocial adjustment to chronic pain is elaborated in this study. The interaction effects between health care need and gender to explain variations in use of health care services indicates that users of services varied in ways that suggest a bias or barrier of their own or of service providers to access services.

Adaptation, Psychological↗
PubMed1996

Economic evaluations in the critical care literature: do they help us improve the efficiency of our unit?

OBJECTIVE: To determine the extent to which economic evaluations published in the critical care literature provide information that can help us to improve the efficiency of our unit. DATA SOURCES: We searched computerized bibliographic databases and manually searched key critical care journals to retrieve all economic evaluations. STUDY SELECTION: We included economic evaluations that dealt with clinical problems relevant to the practice of adult critical care and that compared competing healthcare interventions. DATA ABSTRACTION: Included articles were further evaluated using criteria for minimal methodologic soundness, adopted from the literature, and criteria that we developed to assess the generalizability of results to our clinical setting. DATA SYNTHESIS: We screened 4,167 papers manually and > 450 abstracts and titles in our computer search. One hundred fifty-one papers were retrieved for further evaluation; 29 papers met our inclusion criteria. Of these 29 papers, only 14 (48%) adequately described competing healthcare interventions, 17 (59%) provided sufficient evidence of clinical efficacy, six (21%) identified, measured, and valuated costs appropriately, and three (10%) performed a sensitivity analysis. None of the papers met all four of these criteria for a minimum level of methodologic soundness. Four (14%) of 29 studies which adequately dealt with issues of cost and efficacy were evaluated using our generalizability criteria. Different costing methods precluded the application of the results of three of the four studies to our intensive care unit. CONCLUSIONS: In the critical care literature, very little useful economic information exists to help decision-makers maximize efficiency in their own setting.

Adult↗
PubMed1996

Economic implications of IGT intervention: the case of a "phantom alternative'?

Diabetes is a major chronic disease (or group of diseases). It is associated with a variety of risk factors which promote its occurrence. It is also associated as a risk factor for structural and function damage (complications) in various body systems, especially the cardiovascular, renal, eye and neurological systems. Undoubtedly, diabetes is a disease of major public health importance, both in terms of its impact on the well-being of the population and its economic burden. It is thus natural to look into interventions aimed at reducing the long-term sequelae of the disease or more specifically looking into primary prevention strategies (i.e., interventions prior to the onset of the disease) and their economic implications. The purpose of this paper is to asses whether it is possible to perform economic evaluation of primary prevention strategy(ies) in subject with IGT or whether such a strategy represents, at present, a 'Phantom Alternative'. Unfortunately, the evidence about the effectiveness of primary prevention type interventions are weak at best. It is not surprising that no one has suggested a comprehensive strategy (i.e., who is doing what, to whom, where and how often) for an intervention for subjects with impaired glucose tolerance (IGT). The absence of good evidence about the effectiveness of different IGT interventions preclude a valid economic analysis. 'What-it' or 'modelling' type studies are likely to result in the typical answer-'it depends'. It is recommended, therefore, that an economic evaluation should be performed in conjunction with a clinical trial to determine the effectiveness of different IGT interventions.

Canada↗