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.

Intra-articular Hyaluronic Acid in Treatment of Knee Osteoarthritis: A Meta-analysis

Abstract: ContextIntra-articular hyaluronic acid is a US Food and Drug Administration–approved treatment for knee osteoarthritis (OA); however, its efficacy is controversial.ObjectiveTo evaluate whether intra-articular hyaluronic acid is efficacious in treating knee OA.Data SourcesWe searched for human clinical trials in MEDLINE (1966 through February 2003) and the Cochrane Controlled Trials Register, using the search terms (osteoarthritis, osteoarthrosis, or degenerative arthritis) and (hyaluronic acid, Hyalgan, Synvisc, Artzal, Suplasyn, BioHy, or Orthovisc). We also hand searched manuscript bibliographies that met inclusion criteria, selected rheumatic disease journals, and abstracts from scientific meetings.Study SelectionIncluded were published or unpublished, English and non-English, single- or double-blinded, randomized controlled trials comparing intra-articular hyaluronic acid with intra-articular placebo injection for the treatment of knee OA. Trials also were required to have extractable data on pain reported by 1 of the outcome measures recommended by the Osteoarthritis Research Society.Data ExtractionTwo reviewers independently performed data extraction using standardized data forms. For each trial, we calculated an effect size (small-effect sizes, 0.2-0.5; large-effect sizes, 1.0-1.8, equivalent to a total knee replacement). We used a random-effects model to pool study results, the Cochrane Q test to evaluate heterogeneity, and a funnel plot and the Egger test to evaluate publication bias.Data SynthesisThe overall dropout rate in the 22 selected trials was 12.4%. The pooled effect size for hyaluronic acid was 0.32 (95% confidence interval [CI], 0.17-0.47). There was significant heterogeneity among studies (P<.001). Two outlier trials, both evaluating the highest-molecular-weight hyaluronic acid, had effect sizes in excess of 1.5. However, the third trial of the same compound showed a nearly null effect. When the 3 trials of this compound were removed, heterogeneity was no longer significant (P = .58), and the pooled effect size for intra-articular hyaluronic acid decreased to 0.19 (95% CI, 0.10-0.27). There was evidence of publication bias with an asymmetric funnel plot, a positive Egger test, and identification of 2 unpublished trials whose pooled effect size was 0.07 (95% CI, − 0.15 to 0.28).ConclusionIntra-articular hyaluronic acid has a small effect when compared with an intra-articular placebo. The presence of publication bias suggests even this effect may be overestimated. Compared with lower-molecular-weight hyaluronic acid, the highest-molecular-weight hyaluronic acid may be more efficacious in treating knee OA, but heterogeneity of these studies limits definitive conclusions.

Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration

Abstract: Study design Single blind randomized study. Objectives To compare the effectiveness of lumbar instrumented fusion with cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Summary of background data To the authors' best knowledge, only one randomized study has evaluated the effectiveness of lumbar fusion. The Swedish Lumbar Spine Study reported that lumbar fusion was better than continuing physiotherapy and care by the family physician. Patients and methods Sixty-four patients aged 25-60 years with low back pain lasting longer than 1 year and evidence of disc degeneration at L4-L5 and/or L5-S1 at radiographic examination were randomized to either lumbar fusion with posterior transpedicular screws and postoperative physiotherapy, or cognitive intervention and exercises. The cognitive intervention consisted of a lecture to give the patient an understanding that ordinary physical activity would not harm the disc and a recommendation to use the back and bend it. This was reinforced by three daily physical exercise sessions for 3 weeks. The main outcome measure was the Oswestry Disability Index. Results At the 1-year follow-up visit, 97% of the patients, including 6 patients who had either not attended treatment or changed groups, were examined. The Oswestry Disability Index was significantly reduced from 41 to 26 after surgery, compared with 42 to 30 after cognitive intervention and exercises. The mean difference between groups was 2.3 (-6.7 to 11.4) (P = 0.33). Improvements inback pain, use of analgesics, emotional distress, life satisfaction, and return to work were not different. Fear-avoidance beliefs and fingertip-floor distance were reduced more after nonoperative treatment, and lower limb pain was reduced more after surgery. The success rate according to an independent observer was 70% after surgery and 76% after cognitive intervention and exercises. The early complication rate in the surgical group was 18%. Conclusion The main outcome measure showed equal improvement in patients with chronic low back pain and disc degeneration randomized to cognitive intervention and exercises, or lumbar fusion.

Bayesian Approaches to Randomized Trials

Abstract: Statistical issues in conducting randomized trials include the choice of a sample size, whether to stop a trial early and the appropriate analysis and interpretation of the trial results. At each of these stages, evidence external to the trial is useful, but generally such evidence is introduced in an unstructured and informal manner. We argue that a Bayesian approach allows a formal basis for using external evidence and in addition provides a rational way for dealing with issues such as the ethics of randomization, trials to show treatment equivalence, the monitoring of accumulating data and the prediction of the consequences of continuing a study

Effect of maintenance therapy with varenicline on smoking cessation: a randomized controlled trial.

Abstract: ContextThe majority of cigarette smokers who achieve abstinence relapse within the first year and require many attempts before achieving permanent abstinence. Evidence to support pharmacological treatment for relapse prevention is insufficient.ObjectiveTo determine whether smokers who quit after 12 weeks of treatment with varenicline, a selective α4β2 nicotinic acetylcholine receptor partial agonist, maintain greater continuous abstinence rates (defined as not a single “puff” of a cigarette) than placebo controls during an additional 12 weeks of treatment and until 52 weeks after treatment initiation.Design, Setting, and ParticipantsRandomized controlled trial conducted at multiple medical clinics in 7 countries with follow-up to 52 weeks after study baseline. Of 1927 cigarette smokers recruited between April 2003 and February 2004 and treated for 12 weeks with open-label varenicline titrated to 1 mg twice per day, 1236 (64.1%) did not smoke, use tobacco, or use nicotine replacement therapy during the last week of treatment and 62.8% (n = 1210) were randomized to additional treatment or placebo.InterventionParticipants were randomly assigned to receive either double-blind varenicline, 1 mg twice per day (n = 603), or placebo (n = 607) for an additional 12 weeks.Main Outcome MeasuresCarbon monoxide–confirmed continued abstinence during weeks 13 to 24 and weeks 13 to 52 of the study.ResultsThe carbon monoxide–confirmed continuous abstinence rate was significantly higher for the varenicline group than for the placebo group for weeks 13 to 24 (70.5% vs 49.6%; odds ratio [OR], 2.48; 95% confidence interval [CI], 1.95-3.16; P<.001) as well as for weeks 13 to 52 (43.6% vs 36.9%; OR, 1.34; 95% CI, 1.06-1.69; P = .02). Adverse events reported in the open-label period were mostly mild; no difference in adverse events between varenicline and placebo was observed during the double-blind period.ConclusionsSmokers who achieved abstinence for at least 7 days at the end of 12 weeks of open-label varenicline treatment and were randomized to receive an additional 12 weeks of varenicline treatment showed significantly greater continuous abstinence in weeks 13 to 24 compared with placebo. This advantage was maintained through the nontreatment follow-up to week 52. Varenicline may be an efficacious, safe, and well-tolerated agent for maintaining abstinence from smoking.Trial Registrationclinicaltrials.gov Identifier: NCT00143286

Ginkgo biloba for prevention of dementia: a randomized controlled trial.

Abstract: Context Ginkgo biloba is widely used for its potential effects on memory and cognition. To date, adequately powered clinical trials testing the effect of G biloba on dementia incidence are lacking. Objective To determine effectiveness of G biloba vs placebo in reducing the incidence of all-cause dementia and Alzheimer disease (AD) in elderly individuals with normal cognition and those with mild cognitive impairment (MCI). Design, Setting, and Participants Randomized, double-blind, placebo-controlled clinical trial conducted in 5 academic medical centers in the United States between 2000 and 2008 with a median follow-up of 6.1 years. Three thousand sixty-nine community volunteers aged 75 years or older with normal cognition (n = 2587) or MCI (n = 482) at study entry were assessed every 6 months for incident dementia. Intervention Twice-daily dose of 120-mg extract of G biloba (n = 1545) or placebo (n = 1524). Main Outcome Measures Incident dementia and AD determined by expert panel consensus. Results Five hundred twenty-three individuals developed dementia (246 receiving placebo and 277 receiving G biloba) with 92% of the dementia cases classified as possible or probable AD, or AD with evidence of vascular disease of the brain. Rates of dropout and loss to follow-up were low (6.3%), and the adverse effect profiles were similar for both groups. The overall dementia rate was 3.3 per 100 person-years in participants assigned to G biloba and 2.9 per 100 person-years in the placebo group. The hazard ratio (HR) for G biloba compared with placebo for all-cause dementia was 1.12 (95% confidence interval [CI], 0.94-1.33; P = .21) and for AD, 1.16 (95% CI, 0.97-1.39; P = .11). G biloba also had no effect on the rate of progression to dementia in participants with MCI (HR, 1.13; 95% CI, 0.85-1.50; P = .39). Conclusions In this study, G biloba at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or AD incidence in elderly individuals with normal cognition or those with MCI. Trial Registration clinicaltrials.gov Identifier: NCT00010803