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Biomedical subjects

Andreas Laupacis

Publications and source records attributed to Andreas Laupacis.

At least 73 records · Page 4Linked to original sources
PubMed2003

A survey of the decision-making needs of Canadians faced with complex health decisions.

OBJECTIVE: To describe the decision-making needs of Canadians when faced with 'complex' health decisions characterized by balancing advantages against disadvantages. Although a national report emphasized that public confidence in the health-care system depends on support for personal knowledge and decision-making, there has been no systematic investigation of the Canadian population's decision-making needs. DESIGN: Cross-sectional telephone survey using random digit dialling. PARTICIPANTS: National sample of 635 adults over 18 years of age, living in Canada. RESULTS: Forty-two percentage of eligible contacts participated. Sixty-five percent of contacts reported making 'complex' health decisions, commonly about medical or surgical treatments or birth control, and more commonly by women and by married/separated individuals. Most respondents took an active role in their decisions, often sharing the process with their partner or family. Being younger was associated with a more independent role. Physicians were more often involved in the decisions of respondents with less education. Fifty-nine percent of respondents experienced decisional conflict; more conflict was seen with those who were female and feeling uninformed about options, pressured to select one particular option, and unready or unskilled in decision-making. Less decisional conflict was seen in those who reported birth control decisions and in those who were 70 years and older. Participants used several strategies when deliberating about choices including: information gathering, clarifying their values, and seeking support and information from others. Personal counselling and printed information materials were commonly preferred methods of learning about options. 'Essential' criteria for judging satisfactory decision-making included: having sufficient knowledge about the options, outcomes, and probabilities; being clear about values; selecting and implementing a choice that agrees with personal values; and expressing satisfaction with the choice. CONCLUSIONS: Canadians, particularly women, face difficult decisions and need support and information from credible sources.

Adolescent↗
PubMed2003

The value of positron emission tomography in the clinical evaluation of dementia.

Positron emission tomography (PET) has been promoted as a means of improving the diagnosis of Alzheimer's disease (AD), but the evidence to support its incremental value is unclear. To assess the evidence regarding the use of PET in the clinical evaluation of AD, a systematic review of the English-language literature indexed in MEDLINE (1975-January 2001), the Cochrane Library (issue 4, 2000), and health technology assessment (HTA) reports was conducted. Articles identified by this review process were graded for methodological and reporting quality using a standardized grading scheme. Sixteen original articles and seven HTA reports were identified. In general, the articles addressed: using PET to differentiate AD from normal aging or non-Alzheimer's dementias, PET imaging compared with single positron emission computed tomography imaging, using PET to predict the progression of dementia, and agreement and reliability in the interpretation of PET images. Serious problems with study design and methodology in all articles were identified. Previous HTA reports have generally recommended that PET not be used in the clinical evaluation of dementia. In conclusion, there is little evidence to support the addition of PET to the routine clinical evaluation of patients with suspected or established dementia. Suggestions for future research in this area are offered.

Aged↗
PubMed2003

Warfarin therapy and risk of hip fracture among elderly patients.

STUDY OBJECTIVE: To ascertain the relationship between warfarin therapy and subsequent hip fracture in a large elderly population. DESIGN: Retrospective, population-based cohort study. SETTING: Population-based health care administrative databases for Ontario, Canada. PATIENTS: Elderly patients receiving warfarin (52,701 patients), thyroid replacement therapy (40,555), an oral corticosteroid (43,915), or a proton pump inhibitor (60,383). The proton pump inhibitor group served as controls. MEASUREMENTS AND MAIN RESULTS: The association between warfarin therapy and subsequent hospitalization for hip fracture in elderly patients was examined by researching administrative data from January 1, 1994-March 31, 1999, for the elderly population of Ontario. Relative to patients receiving proton pump inhibitors, patients receiving warfarin (adjusted risk ratio [aRR] 0.94, 95% confidence interval [CI] 0.81-1.09) or thyroid replacement therapy (aRR 1.02, 95% Cl 0.89-1.18) incurred similar risks of hip fracture. As expected, patients receiving oral corticosteroids incurred an increased risk (aRR 1.44, 95% CI 1.21-1.70) relative to patients receiving proton pump inhibitors. CONCLUSION: Warfarin was not associated with increased risk of hip fracture.

Adrenal Cortex Hormones↗
PubMed2002

Oral anticoagulants vs aspirin in nonvalvular atrial fibrillation: an individual patient meta-analysis.

CONTEXT: Patients with nonvalvular atrial fibrillation (AF) have an increased risk of stroke and other vascular events. OBJECTIVE: To compare the risk of vascular and bleeding events in patients with nonvalvular AF treated with vitamin K -inhibiting oral anticoagulants or acetylsalicylic acid (aspirin). DESIGN: Pooled analysis of patient-level data from 6 published, randomized clinical trials. PATIENTS: A total of 4052 patients with AF randomly assigned to receive therapeutic doses of oral anticoagulant or aspirin with or without low-dose oral anticoagulants. MAIN OUTCOME MEASURES: Ischemic and hemorrhagic stroke, other cardiovascular events, all-cause death, and major bleeding events. Person-year incidence rates were calculated to provide crude comparisons. Relative efficacy was assessed using proportional hazards modeling stratified by study. The variation of the oral anticoagulant's relative effect by pertinent patient factors was explored with interaction terms. All analyses were conducted using the intention-to-treat principle. RESULTS: Patients receiving oral anticoagulant and aspirin were balanced for important prognostic factors. There was no significant heterogeneity between trials in the relative efficacy of oral anticoagulant vs aspirin for any outcome. Patients receiving oral anticoagulant were significantly less likely to experience any stroke (2.4 vs 4.5 events per 100 patient-years; hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.43-0.71), ischemic stroke (HR, 0.48; 95% CI, 0.37-0.63), or cardiovascular events (HR, 0.71; 95% CI, 0.59-0.85) but were more likely to experience major bleeding (2.2 vs 1.3 events per 100 patient-years; HR, 1.71; 95% CI, 1.21-2.41). The reduction in ischemic stroke risk was similar in patients with paroxysmal AF (1.5 vs 4.7 events per 100 patient-years; HR, 0.32; 95% CI, 0.16-0.61; P<.001). Treating 1000 patients with AF for 1 year with oral anticoagulant rather than aspirin would prevent 23 ischemic strokes while causing 9 additional major bleeds. Overall all-cause survival did not differ but appeared to improve for oral anticoagulant patients 3 years after therapy was started. CONCLUSIONS: Compared with aspirin, oral anticoagulant significantly decreases the risk of all strokes, ischemic strokes, and cardiovascular events for patients with nonvalvular chronic or paroxysmal AF but modestly increases the absolute risk of major bleeding. The balance of benefits and risks varies by patient subgroup.

Administration, Oral↗
PubMed2002

The Cochrane Collaboration - how is it progressing?

During the last seven years, the Cochrane Collaboration has rapidly developed into an important international organization, producing high quality systematic reviews of randomized trials. Challenges, which it will likely meet, include maintaining the quality of the reviews, ensuring that reviews are done of the most common therapies for important diseases, securing stable funding, and making the format of the reviews more accessible for the average clinician.

Evidence-Based Medicine↗
PubMed2002

Observational study of upper gastrointestinal haemorrhage in elderly patients given selective cyclo-oxygenase-2 inhibitors or conventional non-steroidal anti-inflammatory drugs.

OBJECTIVE: To compare rates of upper gastrointestinal haemorrhage among elderly patients given selective cyclo-oxygenase-2 (COX 2) inhibitors and non-selective non-steroidal anti-inflammatory drugs (NSAIDs). DESIGN: Observational cohort study. SETTING: Administrative data from Ontario, Canada, used from 17 April 2000 to 31 March 2001 to identify population based, NSAID-naive cohorts of patients. PATIENTS: Subjects aged > or =66 years who started taking non-selective NSAIDs (n=5391), diclofenac plus misoprostol (n=5087), rofecoxib (n=14 583), or celecoxib (n=18 908) and a randomly selected control cohort not exposed to NSAIDs (n=100 000). MAIN OUTCOME MEASURES: Rate ratios of hospital admission for upper gastrointestinal haemorrhage in each drug cohort with adjustment for potential confounders. RESULTS: Relative to controls, the multivariate model revealed an increased short term risk of upper gastrointestinal haemorrhage for users of non-selective NSAIDs (adjusted rate ratio 4.0 (95% confidence intervals 2.3 to 6.9)), diclofenac plus misoprostol (3.0 (1.7 to 5.6)), and rofecoxib (1.9 (1.3 to 2.8)) but not celecoxib (1.0 (0.7 to 1.6)). Relative to celecoxib, significantly higher risks of upper gastrointestinal haemorrhage were observed for non-selective NSAIDs (4.4 (2.3 to 8.5)), diclofenac plus misoprostol (3.2 (1.6 to 6.5)), and rofecoxib (1.9 (1.2 to 2.8)). Relative to rofecoxib, non-selective NSAID users were at significantly higher risk of upper gastrointestinal haemorrhage (1.9 (1.0 to 3.5)). CONCLUSIONS: This population based observational study found a lower short term risk of upper gastrointestinal haemorrhage for selective COX-2 inhibitors compared with non-selective NSAIDs.

Aged↗
PubMed2002

Balancing the risks of stroke and upper gastrointestinal tract bleeding in older patients with atrial fibrillation.

OBJECTIVE: To determine how factors that increase the risk of major upper gastrointestinal (GI) tract hemorrhage (recent upper GI tract bleeding or concurrent use of nonsteroidal anti-inflammatory drugs) influence the choice of antithrombotic therapy in older patients (those > or = 65 years) with atrial fibrillation. METHODS: For older patients with atrial fibrillation and no other contraindications to antithrombotic therapy, a Markov decision-analytic model was used to determine the preferred treatment strategy (no antithrombotic therapy, long-term aspirin use, or long-term warfarin sodium use) based on their risk of major upper GI tract hemorrhage. Input data were obtained by a systematic review of MEDLINE. Outcomes were expressed as quality-adjusted life-years (QALYs). RESULTS: For 65-year-old patients with average risks of stroke and upper GI tract bleeding, warfarin therapy was associated with 12.1 QALYs per patient; aspirin therapy, 10.8 QALYs; and no antithrombotic therapy, 10.1 QALYs. For persons with significantly higher risks of upper GI tract bleeding and/or lower risks of stroke, warfarin was no longer clearly the optimal antithrombotic therapy (eg, for 80-year-old persons with a baseline risk of stroke of 4.3% per year who were concurrently taking a conventional nonsteroidal anti-inflammatory drug: warfarin, 7.44 QALYs; aspirin, 7.39 QALYs; and no treatment, 7.21 QALYs). CONCLUSIONS: For older patients with atrial fibrillation and factors that place them at a higher than average risk of upper GI tract bleeding, the optimal choice of antithrombotic therapy to prevent stroke can vary according to the magnitude of this risk. Based on the risks of stroke and upper GI tract bleeding, clinicians can use the treatment recommendations of this study to provide rational stroke prevention therapy for older patients with atrial fibrillation.

Aged↗
PubMed2002

The effect of qualitative vs. quantitative presentation of probability estimates on patient decision-making: a randomized trial.

BACKGROUND: Given the greater uncertainty surrounding probability estimates associated with qualitative (use of words or phrases) descriptions, the use of quantitative (numerical) information to communicate the risks and benefits of therapies is recommended but the impact of its use in decision aids is unexplored. OBJECTIVE: Using stroke prevention in atrial fibrillation as an example, to compare the impact of quantitative vs. qualitative descriptions of probability risk estimates in decision aids on the clinical decision-making process. DESIGN: Randomized trial with a 2 x 2 factorial design. SUBJECTS: A total of 198 volunteers aged 60-80 years. SETTING: Outpatient clinics of a university-affiliated, tertiary-care teaching hospital. METHODS: Participants were asked to imagine that they had atrial fibrillation, and using a decision aid, were then randomized to two ways of receiving pertinent risk information regarding the probability of stroke and major bleeding when taking warfarin, aspirin or no therapy: (1) quantitatively, in which the 2-year probabilities of stroke and major haemorrhage were presented both numerically and graphically with 100 faces (e.g. 8 of 100), and (2) qualitatively in which these probabilities were presented with the use of verbal phrases (e.g. very low, moderate). OUTCOME MEASURES: Primary: decisional conflict. Secondary: participants' choices, knowledge and expectations of outcomes using qualitative and quantitative scales. RESULTS: Participants reviewing quantitative risk information scored better on the informed subscale of the decisional conflict scale (P < 0.05) and, as expected, were better able to estimate numerically their chance of stroke and bleeding when taking warfarin, aspirin or no medication. For the low risk arm, there were no significant differences in treatment choices for the qualitative and quantitative groups. For the moderate risk arm, treatment choices between the two groups were significantly different (P = 0.01), with those in the quantitative group more likely to make an actual choice and to choose therapies at the extremes of effectiveness (warfarin and no treatment). There were no significant differences between the quantitative and qualitative groups in their ability to rank-order their stroke risk when taking warfarin, aspirin and no treatment, overall knowledge about atrial fibrillation and its treatment, and other dimensions of decisional conflict (all P-values >0.05). CONCLUSIONS: For participants without the disease in question, this study found that providing sufficient quantitative risk information makes them feel more informed, which sometimes affects their treatment choices. Further studies are necessary to confirm these findings for patients making actual clinical decisions.

Aged↗
PubMed2002

Effect of discharge summary availability during post-discharge visits on hospital readmission.

OBJECTIVE: To determine if the delivery of hospital discharge summaries to follow-up physicians decreases the risk of hospital readmission. SUBJECTS: Eight hundred eighty-eight patients discharged from a single hospital following treatment for an acute medical illness. SETTING: Teaching hospital in a universal health-care system. DESIGN: We determined the date that each patient's discharge summary was printed and the physicians to whom it was sent. Summary receipt was confirmed by survey and phoning each physician's office. Each patient's hospital chart was reviewed to determine their acute and chronic medical conditions as well as their course in hospital. Using population-based administrative databases, all post-hospitalization visits were identified. For each of these visits, we determined whether the summary was available. MAIN OUTCOME MEASURES: Time to nonelective hospital readmission during 3 months following discharge. RESULTS: The discharge summary was available for only 568 of 4,639 outpatient visits (12.2%). Overall, 240 (27.0%) of patients were urgently readmitted to hospital. After adjusting for significant patient and hospitalization factors, we found a trend toward a decreased risk of readmission for patients who were seen in follow-up by a physician who had received a summary (relative risk 0.74, 95% confidence interval 0.50 to 1.11). CONCLUSIONS: The risk of rehospitalization may decrease when patients are assessed following discharge by physicians who have received the discharge summary. Further research is required to determine if better continuity of patient information improves patient outcomes.

Access to Information↗
PubMed2002

Determination of the clinical importance of study results.

Formal statistical methods for analyzing clinical trial data are widely accepted by the medical community. Unfortunately, the interpretation and reporting of trial results from the perspective of clinical importance has not received similar emphasis. This imbalance promotes the historical tendency to consider clinical trial results that are statistically significant as also clinically important, and conversely, those with statistically insignificant results as being clinically unimportant. In this paper, we review the present state of knowledge in the determination of the clinical importance of study results. This work also provides a simple, systematic method for determining the clinical importance of study results. It uses the relationship between the point estimate of the treatment effect (with its associated confidence interval) and the estimate of the smallest treatment effect that would lead to a change in a patient's management. The possible benefits of this approach include enabling clinicians to more easily interpret the results of clinical trials from a clinical perspective, and promoting a more rational approach to the design of prospective clinical trials.

Data Interpretation, Statistical↗
PubMed2002

Drug policy: making effective drugs available without bankrupting the healthcare system.

To the extent possible, drug policy should be based upon good quality evidence. This must extend beyond the traditional focus on efficacy and safety in carefully selected patients, to evidence about real-world effectiveness, cost-effectiveness and safety of drugs. This paper will consider methods of improving the quality of the evidence currently available, and the implications of requiring that evidence. Historically, there has been a direct link between research evidence and policy at the level of licensing - drugs are only made available after they have been shown to be safe and efficacious in well-designed and independently assessed research studies. We propose that this reliance on evidence be logically extended to cover the formulary inclusion and post-marketing surveillance aspects of modern prescription drug policy. More specifically we propose that the decision to initially list a drug on a benefit formulary be based on evidence from relevant head-to-head comparisons and well-designed cost-effectiveness analyses. This evidence would be produced by industry in cooperation with independent peer-reviewed funding agencies. Drugs could only be added to a formulary if they met specific predetermined criteria, and drugs could be removed as superior alternatives became available. The provincial governments are monopsony buyers of medicines, and they wield the power to determine public payer "market access'for medicines. This power (within and across provinces) could be used more effectively to negotiate price in the context of reimbursement. The effect of different methods of influencing prescribing (e.g., 'limited access?) upon drug utilization and patient outcomes should be rigorously assessed, including the randomization of groups of patients or communities to different strategies. We also propose that all drugs on the formulary would be subject to a well-designed post-marketing surveillance program. This program would build on the existing passive reporting of adverse events by adding a proactive system that would systematically describe the use and impact of drugs. The notion of drug safety would be extended to include not only adverse events, but also inappropriate use of drugs that results inpatients receiving drugs that do not benefit them. Inappropriate use wastes resources and can put patients and populations at risk.

Adverse Drug Reaction Reporting Systems↗
PubMed2002

Comparison of total hip arthroplasty performed with and without cement : a randomized trial.

BACKGROUND: This study was designed to compare the fixation of a Mallory-Head total hip prosthesis with and without cement. METHODS: Two hundred and fifty patients with osteoarthritis of the hip were randomized to receive a Mallory-Head total hip prosthesis designed for insertion with cement or the same prosthesis designed for insertion without cement. Neither the patient nor the outcomes assessor was aware of the type of prosthesis. Outcomes were assessed with respect to mortality, revision arthroplasty, health-related quality of life (evaluated with the Harris hip score, Merle d'Aubign and Postel hip score, McMaster-Toronto Arthritis Patient Preference Disability Questionnaire (MACTAR), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and the time trade-off technique), and the six-minute-walk test. Patients were seen at three, six, and twelve months and yearly thereafter. RESULTS: The prosthesis was inserted with cement in 124 patients and without cement in 126 patients. The mean age of the patients was sixty-four years, 48% were female, and the mean duration of follow-up was 6.3 years. There were thirteen revisions in the group that had fixation with cement and six in the group that had fixation without cement (p = 0.11), and more femoral components were revised in the group that had fixation with cement (twelve versus one; p = 0.002). All health-related quality-of-life measures improved postoperatively in both groups. CONCLUSIONS: In this randomized trial, the group that had the cemented Mallory-Head hip prostheses required more revisions of the femoral component than did the group with the cementless Mallory-Head prostheses, which was perhaps related to the titanium-alloy femoral stem. Our findings are specific to the implants evaluated in this study.

Aged↗
PubMed2002

Factors influencing the adoption of blood alternatives to minimize allogeneic transfusion: the perspective of eight Ontario hospitals.

OBJECTIVE: To identify and describe the factors influencing the use and nonuse of blood-sparing methods such as preoperative autologous donation, acute normovolemic hemodilution, and the use of cell salvage devices, hemostatic agents and erythropoietin. DESIGN: An interview survey. SETTING: Eight Ontario hospitals. METHOD: Interviews were conducted with chiefs of surgery, orthopedics, cardiac surgery and anesthesia, and with heads of transfusion medicine and pharmacy. Hospitals were selected using the qualitative sampling strategy of maximum variation based on their use of the methods (as reported in a previous mail survey). RESULTS: Use of blood-sparing methods was influenced by diverse factors often operating simultaneously. These included the following: characteristics of the method (e.g., evidence of its effectiveness, ease of use, cost); perceptions and experiences of the potential adopters (experience with the method, perception of the current safety of allogeneic blood, perceived convenience or inconvenience of using the method); aspects of the practice setting (inability to move resources between hospital departments, presence of a local clinical champion); and the external environment (patient and public expectations, funding of the blood system, blood shortages). INTERPRETATION: More rational and evidence-based use of blood-sparing methods could be promoted by the adoption of an interdisciplinary, comprehensive, coordinated approach tailored to each patient's needs.

Blood Transfusion↗
PubMed2002

Dissemination of discharge summaries. Not reaching follow-up physicians.

OBJECTIVE: To discover how often hospital discharge summaries were available to physicians seeing patients for follow-up visits after hospitalization. DESIGN: Cohort study. SETTING: Teaching hospital in Ottawa, Ont. PARTICIPANTS: We studied 792 patients discharged from an internal medicine service after treatment for acute illness. We determined when and by which physician each patient was seen during the first 6 months after discharge. We also determined the date each patient's discharge summary was printed and the physicians to whom it was sent. We confirmed that summaries were received by means of a survey or by telephoning physicians' offices. Patients were observed for 6 months or until they were readmitted to hospital. MAIN OUTCOME MEASURES: Proportion of follow-up visits to physicians for which discharge summaries were available. RESULTS: During the observation period, patients made 6619 visits (median six per patient, interquartile range [IQR] 2 to 9) to 914 different physicians (median three per patient, IQR 2 to 4). Discharge summaries were available for only 996 (15%) visits. Summaries were available for only 65 initial visits (8.2%); no summaries were available for any visit for 542 (68.4%) patients. Summaries were most commonly unavailable because they were not generated in time for follow-up visits (20.0%) or were not sent to follow-up physicians (50.8%). CONCLUSION: At our institution, discharge summaries often did not get to physicians seeing patients after discharge from hospital.

Aged↗