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Randomized controlled trial

About: Randomized controlled trial is a research topic. Over the lifetime, 119828 publications have been published within this topic receiving 4861808 citations. The topic is also known as: RCT & randomized control trial.


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Journal ArticleDOI
05 Mar 1997-JAMA
TL;DR: Until the results of large long-term clinical trials evaluating the effects of calcium channel blockers and ACE inhibitors on cardiovascular disease incidence are completed, the available scientific evidence provides strong support for the current national guidelines, which recommend diuretics and beta-blockers as firstline agents and low-dose therapy for all antihypertensive agents.
Abstract: Objective. —To review the scientific evidence concerning the safety and efficacy of various antihypertensive therapies used as first-line agents and evaluated in terms of major disease end points. Data Sources. —MEDLINE searches and previous meta-analyses for 1980 to 1995. Data Selection. —We selected long-term studies that assessed major disease end points as an outcome. For the meta-analysis, we chose placebo-controlled randomized trials. For randomized trials using surrogate end points such as blood pressure, we selected the largest studies that evaluated multiple drugs. Where clinical trial evidence was lacking, we relied on information from observational studies. Data Synthesis. —Diuretics and β-blockers have been evaluated in 18 long-term randomized trials. Compared with placebo, β-blocker therapy was effective in perventing stroke (relative risk [RR], 0.71; 95% confidence interval [CI], 0.59-0.86) and congestive heart failure (RR, 0.58; 95% CI, 0.40-0.84). The findings were similar for high-dose diuretic therapy (for stroke, RR, 0.49; 95% CI, 0.39-0.62; and for congestive heart failure, RR, 0.17; 95% Cl, 0.07-0.41). Low-dose diuretic therapy prevented not only stroke (RR, 0.66; 95% CI, 0.55-0.78) and congestive heart failure (RR, 0.58; 95% CI, 0.44-0.76) but also coronary disease (RR, 0.72; 95% CI, 0.61-0.85) and total mortality (RR, 0.90; 95% CI, 0.81-0.99). Although calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors reduce blood pressure in hypertensive patients, the clinical trial evidence in terms of health outcomes is meager. For several short-acting dihydropyridine calcium channel blockers, the available evidence suggests the possibility of harm. Whether the long-acting formulations and the nondihydropyridine calcium channel blockers are safe and prevent major cardiovascular events in patients with hypertension remains untested and therefore unknown. Conclusion. —Until the results of large long-term clinical trials evaluating the effects of calcium channel blockers and ACE inhibitors on cardiovascular disease incidence are completed, the available scientific evidence provides strong support for the current national guidelines, which recommend diuretics and β-blockers as firstline agents and low-dose therapy for all antihypertensive agents.

857 citations

Journal ArticleDOI
TL;DR: Evidence from this meta-analysis suggests that recent intervention programs for burnout in physicians were associated with small benefits that may be boosted by adoption of organization-directed approaches, providing support for the view that burnout is a problem of the whole health care organization, rather than individuals.
Abstract: Importance Burnout is prevalent in physicians and can have a negative influence on performance, career continuation, and patient care. Existing evidence does not allow clear recommendations for the management of burnout in physicians. Objective To evaluate the effectiveness of interventions to reduce burnout in physicians and whether different types of interventions (physician-directed or organization-directed interventions), physician characteristics (length of experience), and health care setting characteristics (primary or secondary care) were associated with improved effects. Data Sources MEDLINE, Embase, PsycINFO, CINAHL, and Cochrane Register of Controlled Trials were searched from inception to May 31, 2016. The reference lists of eligible studies and other relevant systematic reviews were hand searched. Study Selection Randomized clinical trials and controlled before-after studies of interventions targeting burnout in physicians. Data Extraction and Synthesis Two independent reviewers extracted data and assessed the risk of bias. The main meta-analysis was followed by a number of prespecified subgroup and sensitivity analyses. All analyses were performed using random-effects models and heterogeneity was quantified. Main Outcomes and Measures The core outcome was burnout scores focused on emotional exhaustion, reported as standardized mean differences and their 95% confidence intervals. Results Twenty independent comparisons from 19 studies were included in the meta-analysis (n = 1550 physicians; mean [SD] age, 40.3 [9.5] years; 49% male). Interventions were associated with small significant reductions in burnout (standardized mean difference [SMD] = −0.29; 95% CI, −0.42 to −0.16; equal to a drop of 3 points on the emotional exhaustion domain of the Maslach Burnout Inventory above change in the controls). Subgroup analyses suggested significantly improved effects for organization-directed interventions (SMD = −0.45; 95% CI, −0.62 to −0.28) compared with physician-directed interventions (SMD = −0.18; 95% CI, −0.32 to −0.03). Interventions delivered in experienced physicians and in primary care were associated with higher effects compared with interventions delivered in inexperienced physicians and in secondary care, but these differences were not significant. The results were not influenced by the risk of bias ratings. Conclusions and Relevance Evidence from this meta-analysis suggests that recent intervention programs for burnout in physicians were associated with small benefits that may be boosted by adoption of organization-directed approaches. This finding provides support for the view that burnout is a problem of the whole health care organization, rather than individuals.

855 citations

Journal ArticleDOI
TL;DR: There is still insufficient evidence to draw definitive conclusions about the efficacy of individual herbs and supplements for diabetes; however, they appear to be generally safe.
Abstract: OBJECTIVE —To conduct a systematic review of the published literature on the efficacy and safety of herbal therapies and vitamin/mineral supplements for glucose control in patients with diabetes. RESEARCH DESIGN AND METHODS —We conducted an electronic literature search of MEDLINE, OLDMEDLINE, Cochrane Library Database, and HealthSTAR, from database inception to May 2002, in addition to performing hand searches and consulting with experts in the field. Available clinical studies published in the English language that used human participants and examined glycemic control were included. Data were extracted in a standardized manner, and two independent investigators assessed methodological quality of randomized controlled trials using the Jadad scale. RESULTS —A total of 108 trials examining 36 herbs (single or in combination) and 9 vitamin/mineral supplements, involving 4,565 patients with diabetes or impaired glucose tolerance, met the inclusion criteria and were analyzed. There were 58 controlled clinical trials involving individuals with diabetes or impaired glucose tolerance (42 randomized and 16 nonrandomized trials). Most studies involved patients with type 2 diabetes. Heterogeneity and the small number of studies per supplement precluded formal meta-analyses. Of these 58 trials, the direction of the evidence for improved glucose control was positive in 76% (44 of 58). Very few adverse effects were reported. CONCLUSIONS —There is still insufficient evidence to draw definitive conclusions about the efficacy of individual herbs and supplements for diabetes; however, they appear to be generally safe. The available data suggest that several supplements may warrant further study. The best evidence for efficacy from adequately designed randomized controlled trials (RCTs) is available for Coccinia indica and American ginseng. Chromium has been the most widely studied supplement. Other supplements with positive preliminary results include Gymnema sylvestre , Aloe vera , vanadium, Momordica charantia , and nopal.

853 citations

Journal ArticleDOI
TL;DR: The first-line psychological treatment for PTSD should be trauma-focused (TFCBTor EMDR), and there was some evidence that TFCBT and EMDR were superior to stress management and other therapies, and that stress management was superior to other therapies.
Abstract: Background The relative efficacy of different psychological treatments for chronic post-traumatic stress disorder (PTSD) is unclear. Aims To determine the efficacy of specific psychological treatments for chronic PTSD. Method In a systematic review of randomised controlled trials, eligible studies were assessed against methodological quality criteria and data were extracted and analysed. Results Thirty-eight randomised controlled trials were included in the meta-analysis. Trauma-focused cognitive–behavioural therapy (TFCBT), eye movement desensitisation and reprocessing (EMDR), stress management and group cognitive–behavioural therapy improved PTSD symptoms more than waiting-list or usual care. There was inconclusive evidence regarding other therapies. There was no evidence of a difference in efficacy between TFCBT and EMDR but there was some evidence that TFCBT and EMDR were superior to stress management and other therapies, and that stress management was superior to other therapies. Conclusions The first-line psychological treatment for PTSD should be trauma-focused (TFCBT or EMDR).

853 citations

Journal ArticleDOI
TL;DR: It is concluded that this trial provides evidence of the short-term efficacy of methotrexate in rheumatoid arthritis, but the mechanism of action is unknown and longer trials will be required to determine the ultimate safety and effectiveness of this drug.
Abstract: Twenty-eight patients with refractory rheumatoid arthritis completed a randomized 24-week double-blind crossover trial comparing oral methotrexate (2.5 to 5 mg every 12 hours for three doses weekly) with placebo. The methotrexate group had significant reductions (P less than 0.01 as compared with the placebo group) in the number of tender or painful joints, the duration of morning stiffness, and disease activity according to physician and patient assessments at the 12-week crossover visit; reductions in the number of swollen joints (P less than 0.05) and 15-m walking time (P less than 0.03) also occurred. These variables, as well as the grip strength and erythrocyte sedimentation rate, showed significant (P less than 0.01) improvement at 24 weeks in the population crossed over to methotrexate. A significantly increased frequency (P less than 0.03) of the HLA-DR2 haplotype occurred in the eight patients with the most substantial response to methotrexate. Adverse reactions during methotrexate therapy included transaminase elevation (21 per cent), nausea (18 per cent), and diarrhea (12 per cent); one patient was withdrawn from the trial because of diarrhea. One patient died while receiving the placebo. Methotrexate did not affect measures of humoral or cellular immunity. We conclude that this trial provides evidence of the short-term efficacy of methotrexate in rheumatoid arthritis, but the mechanism of action is unknown. Longer trials will be required to determine the ultimate safety and effectiveness of this drug.

852 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
202317,032
202234,327
202112,220
202010,774
20199,017