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Peter Tugwell

Publications and source records attributed to Peter Tugwell.

71 records · Page 4Linked to original sources
PubMed2002

A comparison of the quality of Cochrane reviews and systematic reviews published in paper-based journals.

This study set out to compare Cochrane reviews and reviews published in paper-based journals. Two assessment tools were used to collect the data, a 23-item checklist developed by Sacks and a nine-item scale developed by Oxman. Cochrane reviews were found to be better at reporting some items and paper-based review at reporting others. The overall quality was found to be low. This represents a serious situation because clinicians, health policy makers, and consumers are often told that systematic reviews represent "the best available evidence." In the period since this study, the Cochrane Collaboration has taken steps to improve the quality of its reviews through, for example, more thorough prepublication refereeing, developments in the training and support offered to reviewers, and improvements in the system for postpublication peer review. In addition, the use of evidence-based criteria (i.e., the QUOROM statement) for reporting systematic reviews may help further to improve their quality.

Evidence-Based Medicine↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. II. Meta-analysis of alendronate for the treatment of postmenopausal women.

OBJECTIVE: To review the effect of alendronate on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE, EMBASE, Current Contents, and the Cochrane Controlled trials registry from 1980 to 1999, and we examined citations of relevant articles and proceedings of international meetings. STUDY SELECTION: We included 11 trials that randomized women to alendronate or placebo and measured bone density for at least 1 yr. DATA EXTRACTION: For each trial, three independent reviewers assessed the methodological quality and abstracted data. DATA SYNTHESIS: The pooled relative risk (RR) for vertebral fractures in patients given 5 mg or more of alendronate was 0.52 [95% confidence interval (CI), 0.43-0.65]. The RR of nonvertebral fractures in patients given 10 mg or more of alendronate was 0.51 (95% CI 0.38-0.69), an appreciably greater effect than for the 5 mg dose. We found a similar reduction in RR across nonvertebral fracture types; in particular, RR reductions for fractures traditionally thought to be "osteoporotic," such as hip and forearm, were very similar to RR reductions for "nonosteoporotic" fractures. Individual studies showed similar results, reflected in the P values of the test of heterogeneity (P = 0.99 for vertebral and 0.88 for nonvertebral fractures). Alendronate produced positive effects on the percentage change in bone density, which increased with both dose and time. After 3 yr of treatment with 10 mg of alendronate or more, the pooled estimate of the difference in percentage change between alendronate and placebo was 7.48% (95% CI 6.12-8.85) for the lumbar spine (2-3 yr), 5.60% (95% CI 4.80-6.39) for the hip (3-4 yr), 2.08% (95% CI 1.53-2.63) for the forearm (2-4 yr), and 2.73% (95% CI 2.27-3.20) for the total body (3 yr). Heterogeneity of the treatment effect of alendronate was not consistently explained by any of our a priori hypotheses; in particular, the effect was very similar in prevention and treatment studies. The pooled RR for discontinuing medication due to adverse effects for 5 mg or greater of alendronate was 1.15 (95% CI 0.93-1.42). The pooled RR for discontinuing medication due to gastro-intestinal (GI) side effects for 5 mg or greater was 1.03 (0.81-1.30, P = 0.83), and the pooled RR for GI adverse effects with continuation of medication was 1.03 (0.98 to 1.07) P = 0.23. CONCLUSIONS: Alendronate increases bone density in both early postmenopausal women and those with established osteoporosis while reducing the rate of vertebral fracture over 2-3 yr of treatment. Reductions in nonvertebral fractures are evident among postmenopausal women without prevalent fractures and have bone mineral density (BMD) levels below the World Health Organization threshold for osteoporosis. The impact on fractures appears consistent across all fracture types, casting doubt on traditional distinctions between osteoporotic and nonosteoporotic fractures.

Alendronate↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. III. Meta-analysis of risedronate for the treatment of postmenopausal osteoporosis.

OBJECTIVE: To review the effect of risedronate on bone density and fractures in postmenopausal women. DATA SOURCES: We searched MEDLINE from 1966 to the end of 2000 and examined citations of relevant articles and the proceedings of international osteoporosis meetings. STUDY SELECTION: We included eight randomized, placebo-controlled trials of postmenopausal women receiving risedronate or placebo with a follow-up of at least one year and providing data on bone density or fracture rate. DATA EXTRACTION: For each trial, two independent reviewers assessed the methodological quality and abstracted data. DATA SYNTHESIS: The major methodological limitation of the trials was the loss to follow-up, which was over 20% in most trials and over 35% in the largest study. However, the magnitude of the treatment effect was unrelated to loss to follow-up, and in one of the largest trials, more high-risk patients were lost to follow-up in the control than in the treatment group. The pooled relative risk (RR) for vertebral fractures in women given 2.5 mg or more of risedronate was 0.64 [95% confidence interval (CI) 0.54, 0.77]. The pooled RR of nonvertebral fractures in patients given 2.5 mg or more of risedronate was 0.73 (95% CI 0.61, 0.87). Risedronate produced positive effects on the percentage change in bone density of the lumbar spine, combined forearm, and femoral neck that were generally larger with the 5-mg daily dose than with cyclical administration or the 2.5-mg dose. The pooled estimate of the difference in percentage change between 5 mg risedronate and placebo after the final year of treatment (1.5-3 yr) was 4.54% (95% CI 4.12, 4.97) for the lumbar spine, and 2.75% (95% CI 2.32, 3.17) at the femoral neck. CONCLUSIONS: Risedronate substantially reduces the risk of both vertebral and nonvertebral fractures. This fracture reduction is accompanied by an increase in bone density of the lumbar spine and femoral neck in both early postmenopausal women and those with established osteoporosis.

Etidronic Acid↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. IV. Meta-analysis of raloxifene for the prevention and treatment of postmenopausal osteoporosis.

OBJECTIVE: To review the effect of raloxifene on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE from 1966 to 2000 and examined citations of relevant articles and the proceedings of international osteoporosis meetings. STUDY SELECTION: We included seven trials that randomized women to raloxifene or placebo, with both groups receiving similar calcium and vitamin D supplementation, and measured bone density for at least one year. DATA EXTRACTION: For each trial, three independent reviewers abstracted the data and assessed the methodological quality using a validated tool. DATA SYNTHESIS: Data from one large dominating trial suggest a reduction in vertebral fractures with a relative risk (RR) of 0.60 [95% confidence interval (CI) 0.50-0.70, P < 0.01]. The RR of nonvertebral fractures in patients given 60 mg or more of raloxifene in the larger study was 0.92 (95% CI 0.79-1.07, P = 0.27). Raloxifene resulted in positive effects on the percentage change in bone density, which increased over time and was independent of dose. At the final year, point estimates and 95% CIs for the differences in percent change in bone density (95% CI) between raloxifene and placebo groups were 1.33 (95% CI 0.37-2.30) for total body, 2.51 (95% CI 2.21-2.82) for lumbar spine, 2.05 (95% CI 0.71-3.39) for combined forearm, and 2.11 (95% CI 1.68-2.53) for combined hip (P < 0.01 at all four sites). Results were similar across studies, and formal tests of heterogeneity did not approach conventional statistical significance. Raloxifene slightly increased rates of withdrawal from therapy as a result of adverse effects (RR 1.15, 95% CI 1.00-1.33, P = 0.05). The pooled RR was significant for hot flashes 1.46 (95% CI 1.23-1.74, P < 0.01) and nonsignificant for leg cramps 1.64 (95% CI 0.84-3.20, P = 0.15). CONCLUSION: Raloxifene increases bone density, and the effect increases over 2 yr. The data suggest a positive impact of raloxifene on vertebral fractures. There was little effect of raloxifene on nonvertebral fractures.

Female↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. V. Meta-analysis of the efficacy of hormone replacement therapy in treating and preventing osteoporosis in postmenopausal women.

OBJECTIVE: To review the effect of hormone replacement therapy (HRT) on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE and EMBASE from 1966 to 1999, the Cochrane Controlled Register, citations of relevant articles, and proceedings of international meetings for eligible randomized controlled trials. We contacted osteoporosis investigators to identify additional studies, and primary authors for unpublished data. STUDY SELECTION: We included 57 studies that randomized postmenopausal women to HRT or a control (placebo or calcium/vitamin D) and were of at least 1 yr in duration. Seven of these studies reported fractures. DATA ABSTRACTION: For each study, three independent reviewers assessed the methodological quality and abstracted the data. DATA SYNTHESIS: HRT showed a trend toward reduced incidence of vertebral fractures [relative risk (RR) 0.66, 95% confidence interval (CI) 0.41-1.07; 5 trials] and nonvertebral fractures (RR 0.87, 95% CI 0.71-1.08; 6 trials). HRT had a consistent effect on bone mineral density (BMD) at all sites. The difference between HRT and control in the percent change in bone density at 2 yr was 6.76 (5.83, 7.89; 21 trials) at the lumbar spine and 4.53 (3.68, 5.36; 14 trials) and 4.12 (3.45, 4.80; 9 trials) at the forearm and femoral neck, respectively. CONCLUSIONS: HRT has a consistent, favorable and large effect on bone density at all sites. The data show a nonsignificant trend toward a reduced incidence in vertebral and nonvertebral fractures.

Estrogen Replacement Therapy↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. VI. Meta-analysis of calcitonin for the treatment of postmenopausal osteoporosis.

OBJECTIVE: To review the effect of calcitonin on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE and EMBASE from 1966 to 2000 and examined citations of relevant articles and the proceedings of international osteoporosis meetings. We contacted osteoporosis investigators to identify additional studies and primary authors for unpublished data. STUDY SELECTION: We included 30 studies that randomized women to calcitonin or an alternative (placebo or calcium and/or vitamin D) and measured bone density or fracture incidence for at least 1 yr. DATA EXTRACTION: For each trial, three independent reviewers assessed the methodological quality and abstracted data. DATA SYNTHESIS: Calcitonin reduced the incidence of vertebral fractures, with a pooled relative risk (RR) of 0.46 [95% confidence interval (CI) 0.25-0.87, P = 0.02, n = 1404, 4 trials]. However, the RR from the one relatively large randomized controlled trial (RCT) was 0.79 (95% CI 0.62-1.00, P = 0.05, n = 1108). For nonvertebral fractures, the pooled RR was 0.52 (95% CI 0.22-1.23, P = 0.14, n = 1481, 3 trials). Once again, the single large trial showed a less impressive effect than the smaller trials (RR 0.80, 95% CI 0.59-1.09, P = 0.16, n = 1245). For bone density of the lumbar spine, the pooled weekly dose of 250 to 2800 IU per week resulted in significant increase in the weighted mean difference (WMD) of 3.74 (2.04-5.43, P < 0.01, n = 2260, 24 trials). The combined forearm showed a similar effect, with a WMD of 3.02 (95% CI 0.98-5.07, P < 0.01, n = 468, 9 trials). At the femoral neck, the pooled weighted mean difference showed a nonsignificant trend toward benefit, WMD 3.80 (95% CI -0.32-7.91, P = 0.07, 9 trials, n = 513). Methodologically weaker studies tended to show greater effects on bone density, and the lumbar spine results suggested the possibility of publication bias. CONCLUSIONS: Calcitonin likely increases bone density in postmenopausal women predominantly at the lumbar spine and forearm for weekly doses of greater than 250 IU, although the true effect may be smaller than the pooled estimate would suggest. Calcitonin likely reduces the risk of vertebral fracture; its effect on nonvertebral fracture remains uncertain.

Calcitonin↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. VII. Meta-analysis of calcium supplementation for the prevention of postmenopausal osteoporosis.

OBJECTIVE: To summarize controlled trials examining the effect of calcium on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE and EMBASE up to 1998 and the Cochrane Controlled Register up to 2000, and we examined citations of relevant articles and proceedings of international meetings. We contacted osteoporosis investigators to identify additional studies, and primary authors for unpublished data. STUDY SELECTION: We included 15 trials (1806 patients) that randomized postmenopausal women to calcium supplementation or usual calcium intake in the diet and reported bone mineral density of the total body, vertebral spine, hip, or forearm, or recorded the number of fractures, and followed patients for at least 1 yr. DATA EXTRACTION: For each trial, three independent reviewers assessed the methodological quality and extracted data. DATA SYNTHESIS: We found calcium to be more effective than placebo in reducing rates of bone loss after two or more years of treatment. The pooled difference in percentage change from baseline was 2.05% [95% confidence interval (CI) 0.24-3.86] for total body bone density, 1.66% (95% CI 0.92-2.39) for the lumbar spine, 1.64% (95% CI 0.70-2.57) for the hip, and 1.91% (95% CI 0.33-3.50) for the distal radius. The relative risk (RR) of fractures of the vertebrae was 0.77, with a wide CI (95% CI 0.54-1.09); the RR for nonvertebral fractures was 0.86 (95% CI 0.43-1.72). CONCLUSIONS: Calcium supplementation alone has a small positive effect on bone density. The data show a trend toward reduction in vertebral fractures, but do not meaningfully address the possible effect of calcium on reducing the incidence of nonvertebral fractures.

Calcium↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. VIII: Meta-analysis of the efficacy of vitamin D treatment in preventing osteoporosis in postmenopausal women.

OBJECTIVE: To review the effect of vitamin D on bone density and fractures in postmenopausal women. DATA SOURCE: We searched MEDLINE and EMBASE from 1966 to 1999 and examined citations of relevant articles and proceedings of international meetings. We contacted osteoporosis investigators and primary authors to identify additional studies and to obtain unpublished data. STUDY SELECTION: We included 25 trials that randomized women to standard or hydroxylated vitamin D with or without calcium supplementation or a control and measured bone density or fracture incidence for at least 1 yr. DATA EXTRACTION: For each trial, three independent reviewers assessed the methodological quality and abstracted data. DATA SYNTHESIS: Vitamin D reduced the incidence of vertebral fractures [relative risk (RR) 0.63, 95% confidence interval (CI) 0.45-0.88, P < 0.01) and showed a trend toward reduced incidence of nonvertebral fractures (RR 0.77, 95% CI 0.57-1.04, P = 0.09). Most patients in the trials that evaluated vertebral fractures received hydroxylated vitamin D, and most patients in the trials that evaluated nonvertebral fractures received standard vitamin D. Hydroxylated vitamin D had a consistently larger impact on bone density than did standard vitamin D. For instance, total body differences in percentage change between hydroxylated vitamin D and control were 2.06 (0.72, 3.40) and 0.40 (-0.25, 1.06) for standard vitamin D. At the lumbar spine and forearm sites, hydroxylated vitamin D doses above 50 microg yield larger effects than lower doses. Vitamin D resulted in an increased risk of discontinuing medication in comparison to control as a result of either symptomatic adverse effects or abnormal laboratory results (RR 1.37, 95% CI 1.01-1.88), an effect that was similar in trials of standard and hydroxylated vitamin D. CONCLUSIONS: Vitamin D decreases vertebral fractures and may decrease nonvertebral fractures. The available data are uninformative regarding the relative effects of standard and hydroxylated vitamin D.

Female↗
PubMed2002

Meta-analyses of therapies for postmenopausal osteoporosis. IX: Summary of meta-analyses of therapies for postmenopausal osteoporosis.

This section summarizes the results of the seven systematic reviews of osteoporosis therapies published in this series [calcium, vitamin D, hormone replacement therapy (HRT), alendronate, risedronate, raloxifene, and calcitonin] and systematic reviews of etidronate and fluoride we have published elsewhere. We highlight the methodological strengths and weaknesses of the individual studies, and summarize the effects of treatments on the risk of vertebral and nonvertebral fractures and on bone density, including effects in different patient subgroups. We provide an estimate of the expected impact of antiosteoporosis interventions in prevention and treatment populations using the number needed to treat (NNT) as a reference. In addition to the evidence, judgements about the relative weight that one places on weaker and stronger evidence, attitudes toward uncertainty, circumstances of patients' and societal values or preferences will, and should, play an important role in decision-making regarding anti-osteoporosis therapy.

Bone Density↗
PubMed2002

Pharmacoeconomics of long-term treatment of rheumatoid arthritis.

Rheumatoid arthritis affects ~ 1% of the population. It is associated with pain, deformity, decreased quality of life and disability that in turn affects patients' ability to work. A variety of disease-modifying antirheumatic drugs are available to control the disease activity of rheumatoid arthritis. The goal of treatment is to improve patients' quality of life and prevent joint destruction. This paper reviews both the clinical aspects of frequently prescribed disease-modifying antirheumatic drugs and the available cost-effectiveness information. Clinical evidence supports the effectiveness of methotrexate, etanercept, infliximab, gold, hydroxychloroquine, leflunomide, sulfasalazine, penicillamine, cyclosporin, azathioprine and corticosteroids. The last four of these are associated with greater toxicity and are only used if less toxic drugs are ineffective. The lack of published economic evaluations of disease-modifying antirheumatic drugs highlights the need for such studies to allow efficacious and cost-effective drugs to be used to prevent the long-term complications of uncontrolled rheumatoid arthritis.

Animals↗
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

Economic comparison of leflunomide and methotrexate in patients with rheumatoid arthritis: an evaluation based on a 1-year randomised controlled trial.

OBJECTIVE: To compare disease-related medical care and productivity costs, and utilities, in 482 patients with rheumatoid arthritis randomised to receive leflunomide, methotrexate or placebo during a 12-month period. DESIGN AND SETTING: Prospective pharmacoeconomic analysis of a 1-year randomised double-blind trial set in North America. PERSPECTIVE: Societal and the Ontario Ministry of Health. METHODS: Information on healthcare resources, out-of-pocket expenses, loss of working time and time spent on chores, related to the disease or the medication, were collected at 4-week intervals and at study discontinuation. Rating scale and standard gamble (SG) utilities (0 = worse; 100 = best) were collected at baseline and at 6 and 12 months or study exit. Medical care costs in Canadian dollars (Can dollars) were calculated using Ontario reimbursement schedules. US patients' expenses were converted to Can dollars using 1995 purchasing power parity. Lost wages were calculated by age and gender according to 1995 Canadian wage data. All costs were adjusted to 1999 Can dollars and arithmetic mean costs were compared using the nonparametric bootstrap. Analysis of covariance was performed to compare utilities between groups. RESULTS: Mean (standard deviation) rating scale values and SG utilities, respectively, for leflunomide, methotrexate and placebo were 67.7 (18.0), 64.8 (18.1) and 57.5 (9.2), and 80.2 (22.1), 83.2 (18.0) and 77.0 (20.5). Both leflunomide and methotrexate had higher rating scale values (p < 0.05) compared with placebo; SG utilities were significantly different between methotrexate and placebo (p < 0.05). Annualised total rheumatoid arthritisb- or drug-related costs for leflunomide, methotrexate and placebo, respectively, were Can dollars 1761, Can dollars 1280 and Can dollars 1324, and medical care costs were Can dollars 753, Can dollars 620 and Can dollars 167 (all costs exclude drug acquisition and monitoring costs). Annual drug acquisition/ routine monitoring costs were estimated, respectively, at Can dollars 3853/Can dollars 483 for leflunomide and Can dollars 258/Can dollars 599 for methotrexate. Differences between overall costs (excluding drug acquisition and monitoring costs) and medical care costs were not statistically significant. The costs of treating patients with leflunomide were significantly higher than for methotrexate when drug acquisition and monitoring costs were included (p < 0.0001). CONCLUSIONS: No statistically significant differences in utilities could be found between leflunomide or methotrexate. When drug monitoring and acquisition costs are excluded, leflunomide has an otherwise similar economic profile compared with methotrexate, the current gold standard. The acquisition cost of leflunomide is a driving factor in increasing the costs of therapy. These higher costs need to be assessed relative to the therapeutic value of leflunomide.

Adolescent↗
PubMed1999

The effects of an 'explicit' values clarification exercise in a woman's decision aid regarding postmenopausal hormone therapy.

OBJECTIVE: To evaluate the incremental effect of a graphic weigh-scale values clarification exercise to explicitly consider the personal importance of the benefits versus the risks in a woman's decision aid regarding postmenopausal hormone therapy. DESIGN: Randomized controlled trial. Intervention Decision aid including information on options, benefits and risks, and their probabilities either followed by: (1) a graphic weigh-scale values clarification exercise to explicitly consider the personal importance of each benefit and risk; or (2) a summary of the main benefits and risks to implicitly consider benefits versus the risks. SAMPLE: Two-hundred and one women aged 50-69 years from Ottawa, Canada, who had never used hormone therapy. OUTCOME: Perceived clarity of values, a sub-scale of the decisional conflict scale; congruence between personal values of benefits and risks (measured on 0-10 importance rating scale) and choices (accept, decline, unsure regarding preventive hormone therapy [HRT]) using discriminant function analysis. RESULTS: There were no statistically significant differences between interventions in perceived clarity of values and overall congruence between values and choices. Amongst those choosing HRT, there was a trend in those exposed to the graphic weigh-scale exercise to have better congruence between values and choices compared to implicit values clarification (P = 0.06). CONCLUSION: The use of the graphic weigh-scale exercise in a decision aid conveys no overall short-term benefit. Further study is needed to specifically determine effects in those changing the status quo and on the quality of patient-practitioner communication and persistence with decisions.

Journal Article↗