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A Laupacis

Publications and source records attributed to A Laupacis.

At least 127 records · Page 7Linked to original sources
PubMed1993

Disease-specific questionnaire for patients with a renal transplant.

A disease-specific questionnaire to assess the quality of life of renal transplant recipients was developed. A list of items of potential relevance to these patients was created and 50 transplant recipients rated the importance of each item. A combination of factor analysis and clinical judgment was then used to create the final questionnaire which consists of 25 questions in 5 dimensions (physical symptoms, fatigue, uncertainty/fear, appearance and emotions). The physical symptoms dimension is patient specific. All questions are scored on a 7-point Likert scale. The reproducibility of the questionnaire when it was administered to stable transplant recipients was high (intraclass correlation coefficients between 0.82 and 0.91 for the 5 dimensions). The scores of all dimensions except appearance improved 6 months after transplantation, when compared to pretransplantation scores. Patients who had a well-functioning graft (creatinine < 250 mmol/l) had higher scores than those with poorly functioning grafts. This questionnaire is easy to administer and is valid, reproducible in stable patients and responsive to change.

Adult↗
PubMed1993

The effect of elective total hip replacement on health-related quality of life.

The effect of total hip replacement on the health-related quality of life of patients who have osteoarthrosis was examined as part of a randomized, controlled trial comparing femoral head prostheses that were inserted with or without cement. One hundred and eighty-eight patients were followed for three months: 179 of them, for six months; 156, for one year; and ninety, for two years. The health-related quality of life was assessed with use of the Harris hip score, the Merle d'Aubigné hip score, the Sickness Impact Profile, the Western Ontario and McMaster University (WOMAC) Osteoarthritis Index, the McMaster--Toronto Arthritis (MACTAR) Patient Preference Disability Questionnaire, and the time trade-off technique as a measure of utility. Patients also took the six-minute-walk test. The mean age of the patients in the study was sixty-four years (range, forty to seventy-five years); ninety-seven patients (53 per cent) were men and ninety-four (50 per cent) had a prosthesis inserted with cement. Only three of 188 patients refused to return for quality-of-life assessments. There was significant improvement in all health-related quality-of-life measures and in the six-minute-walk test after the operation (p < 0.01 for all items, except for the work dimension of the Sickness Impact Profile at three months [p = 0.07]). Most of the improvement had occurred by three months postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

How attractive does a new technology have to be to warrant adoption and utilization? Tentative guidelines for using clinical and economic evaluations.

Because economic evaluations of health care services are being published with increasing frequency it is important to (a) evaluate them rigorously and (b) compare the net benefit of the application of one technology with that of others. Four "levels of evidence" that rate economic evaluations on the basis of their methodologic rigour are proposed. They are based on the quality of the methods used to estimate clinical effectiveness, quality of life and costs. With the use of the magnitude of the incremental net benefit of a technology, therapies can also be classified into five "grades of recommendation." A grade A technology is both more effective and cheaper than the existing one, whereas a grade E technology is less or equally effective and more costly. Those of grades B through D are more effective and more costly. A grade B technology costs less than $20,000 per quality-adjusted life-year (QALY), a grade C one $20,000 to $100,000/QALY and a grade D one more than $100,000/QALY. Many issues other than cost effectiveness, such as ethical and political considerations, affect the implementation of a new technology. However, it is hoped that these guidelines will provide a framework with which to interpret economic evaluations and to identify additional information that will be useful in making sound decisions on the adoption and utilization of health care services.

Canada↗
PubMed1992

The impact of recombinant human erythropoietin on medical care costs for hemodialysis patients in Canada.

Recombinant human erythropoietin (r-HuEPO) is an established and effective therapy for anemia related to end stage renal disease. In addition to its clinical effects, it has been associated with significant improvements in quality of life for anemic hemodialysis patients. The therapy's impact on overall medical care expenditures for these patients remains uncertain, however. In this study, we examine the costs of r-HuEPO as well as potential offsetting reductions in other medical care costs that might result from the therapy. We used data from a randomized clinical trial, a longitudinal study of hemodialysis patients and the clinical literature to estimate the impact of r-HuEPO on transfusion requirements, transfusion-related illness, hospitalization and transplant success for these patients. We estimate that for patients that otherwise would be transfused, the therapy would reduce blood requirements by nearly 10 units per patient annually and hospital use by 8 days per year. In addition, increased transplant success due to r-HuEPO might result in 150 fewer patient months of dialysis treatments each year. Comparing the dollar value of these reductions with the cost of therapy yields a base case net increase in medical care expenditures of $3425 per patient year. Under varying assumptions, the estimates range from a net cost of $8320 to a net saving of $1775 per patient year.

Anemia↗
PubMed1992

A disease-specific questionnaire for assessing quality of life in patients on hemodialysis.

A disease-specific questionnaire was developed for patients receiving chronic hemodialysis by interviewing patients to determine which aspects of their quality of life were adversely affected by their disease. The final questionnaire contained 26 questions in five dimensions (physical symptoms, fatigue, depression, relationships with others, frustration). The questionnaire demonstrated construct validity when compared with the Sickness Impact Profile, time trade-off technique and an exercise stress test. It was reproducible in stable, placebo-treated patients (correlation coefficient 0.85-0.98 for the 5 dimensions). It was more responsive than other measures in detecting an improvement with erythropoietin therapy in a randomized, placebo-controlled trial. This questionnaire should be useful for the assessment of the effect of various interventions upon the quality of life of hemodialysis patients.

Anemia↗
PubMed1992

Erythropoietin for anaemia in haemodialysis patients: results of a maintenance study (the Canadian Erythropoietin Study Group).

Most published studies of recombinant human erythropoietin (rHuEpo) have been of limited duration and in small patient populations. The present study examines the long-term effects of rHuEpo in 98 haemodialysis patients treated for up to 18 months. All patients had completed a 6 month placebo-controlled study of rHuEpo. Patients previously on placebo (group 1; n = 31) received rHuEpo at an initial dose of 50 U/kg thrice weekly with subsequent dose adjustments to maintain haemoglobin (Hb) in the range 105-120 g/l. Patients previously on rHuEpo (group 2; n = 67) continued on their usual dose with adjustments made to maintain Hb at 105-120 g/l. Haematological parameters were measured every 2 weeks. Quality of life, assessed by a disease-specific kidney disease questionnaire (KDQ), was measured every 6 months. Mean Hb in group 1 increased from 74.2 +/- 11.4 g/l at baseline to 112.9 +/- 12.6 g/l after 12 months of rHuEpo therapy. After 12 weeks of rHuEpo therapy Hb in groups 1 and 2 was indistinguishable. Hb remained constant in both groups throughout the period of follow-up. Mean rHuEpo dose requirements were similar in both groups. At the end of the study the mean intravenous rHuEpo dose in group 1 patients was 176.6 +/- 154.4 and in group 2 patients was 210.0 +/- 144.0 U/kg per week. Access failure was increased during rHuEpo therapy in patients with synthetic grafts (46% versus 7% failures compared to fistulae; P less than 0.001). Group 1 patients receiving rHuEpo had a significant increase in diastolic but not systolic blood pressure despite a 32% increase in overall antihypertensive prescriptions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

How should results from completed studies influence ongoing clinical trials? The CAFA Study experience.

Seven randomized studies during the past 5 years have evaluated or are evaluating the efficacy of warfarin or aspirin or both in decreasing the risk of embolic events in patients with nonrheumatic atrial fibrillation. By March 1990, two of the studies had been published, both of which showed a statistically significant decrease in embolic events in patients treated with warfarin and a low rate of major bleeding events. The investigators associated with the other ongoing studies were forced to consider how these results should affect the decision to recruit and continue follow-up of patients in their own studies. The Steering Committee of the Canadian Atrial Fibrillation Anticoagulation (CAFA) study thought the newly published results from other studies were valid, clinically important, and generalizable. The committee considered the following options for the CAFA study: continue patient recruitment as planned, provide the data available in CAFA to its External Safety and Efficacy Monitoring Committee for analysis to determine whether the CAFA data already showed a benefit of warfarin, stop patient recruitment but continue to follow patients in the group to which they were assigned, stop the trial immediately and perform a final analysis, and attempt to perform a meta-analysis of all data available from all trials. The Steering Committee of CAFA decided that the evidence of benefit with warfarin, from the two published studies, was sufficiently compelling as to stop recruitment into CAFA without any preliminary examination of the CAFA data.

Aspirin↗
PubMed1991

Use of acetylsalicylic acid by physicians and in the community.

OBJECTIVE: To determine physicians' attitudes toward prescribing acetylsalicylic acid (ASA), physicians' own use of ASA and the prevalence of ASA use in the community following the trials of ASA for primary prevention of coronary heart disease. DESIGN: Random sample surveys of physicians and the general public by mail and telephone respectively and a mail survey of a selected panel of expert cardiologists and neurologists. SETTING: London, Ont., and surrounding Middlesex County. PARTICIPANTS: A total of 210 physicians (77% of eligible subjects), including family practitioners and most types of specialists, with an active medical licence and 666 English-speaking people (75% of eligible subjects) aged 18 years or more living in a household with active, listed telephone service. MAIN OUTCOME MEASURE: Long-term ASA use (at least 80 mg on alternate days for 4 or more consecutive weeks) for the treatment of atherosclerosis. MAIN RESULTS: Sampled physicians and experts agreed that long-term ASA therapy was indicated in patients with unstable angina, a transient ischemic episode or recent myocardial infarction but not for primary prevention in healthy middle-aged men and women at low risk for ischemic vascular disease. Both groups were uncertain about the role of ASA in primary prevention in asymptomatic people with risk factors for atherosclerosis. Nine (16%) of the 55 male physicians aged 50 years or more took ASA routinely for primary prevention. In the community survey almost all those who used ASA routinely were 50 years or older. The proportions of men and women in this age group who used ASA routinely for any reason were 19% (95% confidence limits [CLs] 11 and 28) and 14% (95% CLs 8 and 19) respectively; the proportions of men and women who used ASA routinely and apparently for primary prevention were 8% and 1% respectively. A total of 43% (95% CLs 30 and 57) of those with apparent ischemic vascular disease took ASA routinely. Medically unsupervised long-term ASA use for primary or secondary prevention of ischemic vascular disease was uncommon (reported by 2% of those who used the drug routinely). CONCLUSIONS: Physicians generally agree on a role for long-term ASA therapy in the secondary prevention of ischemic vascular disease. However, the prevalence of long-term ASA use in people with overt atherosclerosis in the community may be less than optimal. The role of the drug in the primary prevention of ischemic vascular disease is less accepted. Long-term ASA use in the community for primary prevention is uncommon but detectable.

Adolescent↗
PubMed1991

Canadian Atrial Fibrillation Anticoagulation (CAFA) Study.

The Canadian Atrial Fibrillation Anticoagulation Study was a randomized double-blind placebo-controlled trial to assess the potential of warfarin to reduce systemic thromboembolism and its inherent risk of hemorrhage. As a result of the publication of two other "positive" studies of similar design and objective, this study was stopped early before completion of its planned recruitment of 630 patients. There were 187 patients randomized to warfarin and 191 to placebo. Permanent discontinuation of study medication occurred in 26% of warfarin-treated and 23% of placebo-treated patients. The target range of the international normalized ratio was 2 to 3. For the warfarin-treated patients, the international normalized ratio was in the target range 43.7% of the study days, above it 16.6% of the study days and below it 39.6% of the study days. Fatal or major bleeding occurred at annual rates of 2.5% in warfarin-treated and 0.5% in placebo-treated patients. Minor bleeding occurred in 16% of patients receiving warfarin and 9% receiving placebo. The primary outcome event cluster was nonlacunar stroke, noncentral nervous systemic embolism and fatal or intracranial hemorrhage. Events were included in the primary analysis of efficacy if they occurred within 28 days of permanent discontinuation of the study medication. The annual rates of the primary outcome event cluster were 3.5% in warfarin-treated and 5.2% in placebo-treated patients, with a relative risk reduction of 37% (95% confidence limits, -63.5%, 75.5%, p = 0.17).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

The use of generic and specific quality-of-life measures in hemodialysis patients treated with erythropoietin. The Canadian Erythropoietin Study Group.

The effect of recombinant human erythropoietin (EPO) on the quality of life and exercise capacity of 118 hemodialysis patients was assessed in a randomized, double-masked placebo-controlled trial. Patients were randomized into three groups: 1) placebo, 2) EPO to achieve a hemoglobin of 95-110 g/L and 3) EPO to achieve a hemoglobin of 115-130 g/L. Patients were followed for six months. Quality of life was assessed using a disease-specific measure [the Kidney Disease Questionnaire (KDQ)] and two generic measures [Sickness Impact Profile (SIP) and the Time Trade OFF (TTO)]. The KDQ contains five dimensions. Functional capacity was assessed with a Six-Minute Walk test (SMW) and an Exercise Stress Test (EST). The mean hemoglobin at six months was 74, 102, and 117 gm/l in groups one, two and three, respectively. There was a marked improvement in quality of life with EPO therapy, but no difference between groups 2 and 3. The outcome measure that was the most responsive to change was the KDQ (P less than .001 for the fatigue and physical symptoms dimensions). The aggregate global (P less than .02) and physical (P = .005) scores of the SIP improved with EPO therapy, the psychosocial score did not. There was no improvement in the TTO. There was an improvement in the EST (P = .02) but not in the SMW. The reproducibility of the outcome measures in placebo-treated patients varied between 0.80 and 0.98 (intra-class correlation coefficient). The correlation among the outcome measures at six months was statistically significant in most cases, as was the correlation of change scores between baseline and six months.

Adult↗
PubMed1991

A randomized double-blind study of recombinant human erythropoietin in anaemic hemodialysis patients. Canadian Erythropoietin Study Group.

This study suggests that both the quality of life and exercise capacity of anaemic hemodialysis patients is improved with EPO therapy. This was seen most convincingly in the dimensions of fatigue and physical symptoms. There was no difference in improvement in quality of life or exercise capacity between patients with a mean hemoglobin level of 102 g/L and those with a mean hemoglobin level of 117 g/L. There was an increase in diastolic blood pressure in the EPO-treated patients, especially those randomized to the high EPO group.

Adult↗
PubMed1990

Therapeutic priorities of Canadian internists.

We surveyed 175 members of the Canadian Society of Internal Medicine to determine how they would rank seven commonly used treatments as to their clinical usefulness. A total of 70% of the respondents judged that the treatment of severe hypertension was the most beneficial. Coronary artery bypass surgery and treatment with acetylsalicylic acid for transient ischemic attacks were ranked next most useful. Cholestyramine therapy for hypercholesterolemia, the treatment of mild hypertension, isoniazid therapy for inactive tuberculosis and carotid endarterectomy in patients with mild stroke formed the final cluster. Except for treatment of severe hypertension there was a wide variation in the physicians' enthusiasm for the various treatments. Possible explanations for this variation include physicians' lack of awareness of the results of clinical trials, the wide range of risk reductions found in various trials of the same therapy, an unwillingness by physicians to generalize from clinical trials to individual patients, individual physicians' placement of different values on the morbidity associated with various diseases, and the fact that physicians may rarely explicitly compare the usefulness of therapies. In general, the number of patients needed to be treated to save one life better reflected the physicians' judgements than did the relative risk reduction.

Attitude of Health Personnel↗
PubMed1990

The cost-effectiveness of routine post myocardial infarction exercise stress testing.

The cost-effectiveness of the strategy of a routine pre-discharge exercise test (followed by coronary angiography and coronary artery bypass surgery if indicated) in patients with an uncomplicated myocardial infarction was compared with a policy of no routine exercise testing. Using data from the literature, a decision tree was developed to estimate the number of lives saved by the routine exercise test strategy (12 lives saved per 1000 tests), as well as the number of angiograms and coronary artery bypass procedures that would be performed. It was assumed that surgery decreases one year mortality by 25%. The resources consumed by bypass surgery were obtained from a chart review and the costs were estimated using a method of fully allocated costing. Both direct and indirect costs were included. The average cost of coronary artery bypass surgery was $14,958 (1985 Canadian dollars). The cost of routine exercise testing was $255,726 per life saved. With sensitivity analyses this varied from $139,487 (coronary bypass surgery 50% effective) to $1,022,904 (bypass surgery 7.5% effective). A routine post myocardial infarction stress test is an example of how a relatively inexpensive technology, by leading to other expensive clinical actions, can consume a significant amount of resources.

Angiography↗