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.

Surgical compared with nonoperative treatment for lumbar degenerative spondylolisthesis. four-year results in the Spine Patient Outcomes Research Trial (SPORT) randomized and observational cohorts.

Abstract: Background: The management of degenerative spondylolisthesis associated with spinal stenosis remains controversial. Surgery is widely used and has recently been shown to be more effective than nonoperative treatment when the results were followed over two years. Questions remain regarding the long-term effects of surgical treatment compared with those of nonoperative treatment. Methods: Surgical candidates from thirteen centers with symptoms of at least twelve weeks' duration as well as confirmatory imaging showing degenerative spondylolisthesis with spinal stenosis were offered enrollment in a randomized cohort or observational cohort. Treatment consisted of standard decompressive laminectomy (with or without fusion) or usual nonoperative care. Primary outcome measures were the Short Form-36 (SF-36) bodily pain and physical function scores and the modified Oswestry Disability Index at six weeks, three months, six months, and yearly up to four years. Results: In the randomized cohort (304 patients enrolled), 66% of those randomized to receive surgery received it by four years whereas 54% of those randomized to receive nonoperative care received surgery by four years. In the observational cohort (303 patients enrolled), 97% of those who chose surgery received it whereas 33% of those who chose nonoperative care eventually received surgery. The intent-to-treat analysis of the randomized cohort, which was limited by nonadherence to the assigned treatment, showed no significant differences in treatment outcomes between the operative and nonoperative groups at three or four years. An as-treated analysis combining the randomized and observational cohorts that adjusted for potential confounders demonstrated that the clinically relevant advantages of surgery that had been previously reported through two years were maintained at four years, with treatment effects of 15.3 (95% confidence interval, 11 to 19.7) for bodily pain, 18.9 (95% confidence interval, 14.8 to 23) for physical function, and −14.3 (95% confidence interval, −17.5 to −11.1) for the Oswestry Disability Index. Early advantages (at two years) of surgical treatment in terms of the secondary measures of bothersomeness of back and leg symptoms, overall satisfaction with current symptoms, and self-rated progress were also maintained at four years. Conclusions: Compared with patients who are treated nonoperatively, patients in whom degenerative spondylolisthesis and associated spinal stenosis are treated surgically maintain substantially greater pain relief and improvement in function for four years. Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

Statistical Power, Sample Size, and Their Reporting in Randomized Controlled Trials

Abstract: Objective. —To describe the pattern over time in the level of statistical power and the reporting of sample size calculations in published randomized controlled trials (RCTs) with negative results. Design. —Our study was a descriptive survey. Power to detect 25% and 50% relative differences was calculated for the subset of trials with negative results in which a simple two-group parallel design was used. Criteria were developed both to classify trial results as positive or negative and to identify the primary outcomes. Power calculations were based on results from the primary outcomes reported in the trials. Population. —We reviewed all 383 RCTs published inJAMA, Lancet, and theNew England Journal of Medicinein 1975, 1980, 1985, and 1990. Results. —Twenty-seven percent of the 383 RCTs (n=102) were classified as having negative results. The number of published RCTs more than doubled from 1975 to 1990, with the proportion of trials with negative results remaining fairly stable. Of the simple two-group parallel design trials having negative results with dichotomous or continuous primary outcomes (n=70), only 16% and 36% had sufficient statistical power (80%) to detect a 25% or 50% relative difference, respectively. These percentages did not consistently increase overtime. Overall, only 32% of the trials with negative results reported sample size calculations, but the percentage doing so has improved over time from 0% in 1975 to 43% in 1990. Only 20 of the 102 reports made any statement related to the clinical significance of the observed differences. Conclusions. —Most trials with negative results did not have large enough sample sizes to detect a 25% or a 50% relative difference. This result has not changed over time. Few trials discussed whether the observed differences were clinically important. There are important reasons to change this practice. The reporting of statistical power and sample size also needs to be improved. (JAMA. 1994;272:122-124)

The VA cooperative randomized study of surgery for coronary arterial occlusive disease II. Subgroup with significant left main lesions.

Abstract: From a large cooperative prospective randomized study, data relating to a subgroup of 113 patients with angina pectoris and a significant lesion of the left main coronary artery were analyzed. Of these patients, 53 had been randomly allocated to a medical treatment group and 60 to a surgical treatment group. The former group received conventional medical treatment, while the surgical treatment group received one or more aortocoronary saphenous vein bypass grafts. Important risk factors were approximately uniformly distributed between the two groups. Both are being followed up to 60 months (average follow-up, 30 months). To date, 12 of 60 surgical patients (20%) and 19 of 53 medical patients (36%) died (P less than 0.06). The operative (30-day) mortality declined from a rate of 25% for the first 2 years of the study to 7% for the last 3 years. Of patients randomized in the latter 3 years of the study, 12 of 41 medical patients (29%) and three of 42 surgical patients (7%) died (P less than 0.01). The average follow-up period in this group was 24 months. The proportion surviving 24 months was clearly larger in the surgically treated group (P less than 0.02). The difference in the proportion of patients surviving after surgery as compared with medical treatment was greatest in patients with additional significant disease involving the right coronary artery, with or without left ventricular dysfunction. Relief of angina as assessed by an "anginal score" was also better in surgical patients to a significant degree. Graft-patency rates correlated well with relief of angina, but objective studies including treadmill testing are not yet available.

Efficacy and Tolerability of Long-Acting Injectable Naltrexone for Alcohol Dependence: A Randomized Controlled Trial

Abstract: ContextAlcohol dependence is a common disorder associated with significant morbidity and mortality. Naltrexone, an opioid antagonist, has been shown to be effective for treatment of alcohol dependence. However, adherence to daily oral pharmacotherapy can be problematic, and clinical acceptance and utility of oral naltrexone have been limited.ObjectiveTo determine efficacy and tolerability of a long-acting intramuscular formulation of naltrexone for treatment of alcohol-dependent patients.Design, Setting, and ParticipantsA 6-month, randomized, double-blind, placebo-controlled trial conducted between February 2002 and September 2003 at 24 US public hospitals, private and Veterans Administration clinics, and tertiary care medical centers. Of the 899 individuals screened, 627 who were diagnosed as being actively drinking alcohol-dependent adults were randomized to receive treatment and 624 received at least 1 injection.InterventionAn intramuscular injection of 380 mg of long-acting naltrexone (n = 205) or 190 mg of long-acting naltrexone (n = 210) or a matching volume of placebo (n = 209) each administered monthly and combined with 12 sessions of low-intensity psychosocial intervention.Main Outcome MeasureThe event rate of heavy drinking days in the intent-to-treat population.ResultsCompared with placebo, 380 mg of long-acting naltrexone resulted in a 25% decrease in the event rate of heavy drinking days (P = .03) and 190 mg of naltrexone resulted in a 17% decrease (P = .07). Sex and pretreatment abstinence each showed significant interaction with the medication group on treatment outcome, with men and those with lead-in abstinence both exhibiting greater treatment effects. Discontinuation due to adverse events occurred in 14.1% in the 380-mg and 6.7% in the 190-mg group and 6.7% in the placebo group. Overall, rate and time to treatment discontinuation were similar among treatment groups.ConclusionsLong-acting naltrexone was well tolerated and resulted in reductions in heavy drinking among treatment-seeking alcohol-dependent patients during 6 months of therapy. These data indicate that long-acting naltrexone can be of benefit in the treatment of alcohol dependence.