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.

Intention-to-treat concept: A review.

Abstract: Randomized controlled trials often suffer from two major complications, ie, noncompliance and missing outcomes One potential solution to this problem is a statistical concept called intention-to-treat (ITT) analysis ITT analysis includes every subject who is randomized according to randomized treatment assignment It ignores noncompliance, protocol deviations, withdrawal, and anything that happens after randomization ITT analysis maintains prognostic balance generated from the original random treatment allocation In ITT analysis, estimate of treatment effect is generally conservative A better application of the ITT approach is possible if complete outcome data are available for all randomized subjects Per-protocol population is defined as a subset of the ITT population who completed the study without any major protocol violations

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Abstract: Objectives To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect. Design Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials. Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015. Eligibility criteria for study selection Randomised, double blind, placebo controlled trials of supplementation with vitamin D 3 or vitamin D 2 of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome. Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit. Systematic review registration PROSPERO CRD42014013953.

Collaborative management to achieve treatment guidelines : impact on depression in primary care

Abstract: Objective. —To compare the effectiveness of a multifaceted intervention in patients with depression in primary care with the effectiveness of "usual care" by the primary care physician. Design. —A randomized controlled trial among primary care patients with major depression or minor depression. Patients. —Over a 12-month period a total of 217 primary care patients who were recognized as depressed by their primary care physicians and were willing to take antidepressant medication were randomized, with 91 patients meeting criteria for major depression and 126 for minor depression. Interventions. —Intervention patients received increased intensity and frequency of visits over the first 4 to 6 weeks of treatment (visits 1 and 3 with a primary care physician, visits 2 and 4 with a psychiatrist) and continued surveillance of adherence to medication regimens during the continuation and maintenance phases of treatment. Patient education in these visits was supplemented by videotaped and written materials. Main Outcome Measures. —Primary outcome measures included short-term (30-day) and long-term (90-day) use of antidepressant medication at guideline dosage levels, satisfaction with overall care for depression and antidepressant medication, and reduction in depressive symptoms. Results. —In patients with major depression, the intervention group had greater adherence than the usual care controls to adequate dosage of antidepressant medication for 90 days or more (75.5% vs 50.0%;P Conclusion. —A multifaceted intervention consisting of collaborative management by the primary care physician and a consulting psychiatrist, intensive patient education, and surveillance of continued refills of antidepressant medication improved adherence to antidepressant regimens in patients with major and with minor depression. It improved satisfaction with care and resulted in more favorable depressive outcomes in patients with major, but not minor, depression. (JAMA. 1995;273:1026-1031)