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Results for “Randomized controlled trials”

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PubMed1995

Octreotide and heater probe thermocoagulation for arrest of peptic ulcer hemorrhage. A prospective, randomized, controlled trial.

We carried out a prospective, randomized, controlled trial over a 7-month period to assay the hemostatic effects of octreotide and heater probe thermocoagulation (HPT) in 54 patients with active peptic ulcer bleeding or nonbleeding visible vessels at the ulcer base. Nineteen patients received octreotide 100 micrograms bolus i.v. followed by 25 micrograms/h i.v. for 3 days. Twenty patients received HPT. Fifteen patients received ranitidine 100 mg i.v. every 12 h. The three groups were matched for sex, age, location of bleeders, endoscopic findings, shock, and initial hemoglobin. Ultimate hemostasis was obtained in 11 (58%) of the octreotide group, 18 (90%) of the heater probe group, and 8 (53%) of the control group (p < 0.05). Volume of blood transfused, number of patients receiving operation, hospital stay, and number of deaths were not statistically significant among the three groups. We conclude that HPT is more effective than octreotide in the arrest of peptic ulcer bleeding.

Aged↗

PubMed1990

Intravenous streptokinase in the management of a subset of patients with unstable angina: a randomized controlled trial.

We report the results of a randomized controlled trial of intravenous streptokinase in a subset of patients with unstable angina. Seventy-six patients were admitted with prolonged (more than 20 minutes) angina at rest of less than 3 weeks onset. Fifty-two patients continued to have more than 3 episodes of prolonged angina in 48 hours on medical therapy with metoprolol, isosorbide dinitrate, nifedipine and intravenous nitroglycerin. Forty-eight patients consented to enter the study and were randomized into two groups. The first group, of 24 patients, received 1.5 million units of streptokinase infusion and the second group, also of 24 patients, received a placebo. Pain relief within 48 hours was achieved in 19/24 (79.1%) patients after streptokinase infusion as compared to 9/24 (37.5%) of the controls (P less than 0.05). Approximately 90% (17/19) of patients responding to streptokinase therapy were relieved of chest pain within the first six hours as against none in the controls. The incidence of acute myocardial infarction within six months was 12.5% (3/24) in those receiving streptokinase and 25% (6/24) in the controls. Mortality at six months stood at 8.33% (2/24) in the treated patients and 16.6% (4/24) in the controls. Intravenous streptokinase thus appears to be of benefit in patients with angina at rest of recent onset which does not respond to conventional medical therapy.

Angina Pectoris↗

PubMed2003

Hierarchy of evidence: from case reports to randomized controlled trials.

In the hierarchy of research designs, the results of randomized controlled trials are considered the highest level of evidence. Randomization is the only method for controlling for known and unknown prognostic factors between two comparison groups. Lack of randomization predisposes a study to potentially important imbalances in baseline characteristics between two study groups. There is a hierarchy of evidence, with randomized controlled trials at the top, controlled observational studies in the middle, and uncontrolled studies and opinion at the bottom. This hierarchy has not been supported in two recent publications in the New England Journal of Medicine which identified nonsignificant differences in results between randomized, controlled trials, and observational studies. The current authors provide an approach to organizing published research on the basis of study design, a hierarchy of evidence, a set of principles and tools that help clinicians distinguish ignorance of evidence from real scientific uncertainty, distinguish evidence from unsubstantiated opinions, and ultimately provide better patient care.

Evidence-Based Medicine↗

PubMed1978

The importance of beta, the type II error and sample size in the design and interpretation of the randomized control trial. Survey of 71 "negative" trials.

Seventy-one "negative" randomized control trials were re-examined to determine if the investigators had studied large enough samples to give a high probability (greater than 0.90) of detecting a 25 per cent and 50 per cent therapeutic improvement in the response. Sixty-seven of the trials had a greater than 10 per cent risk of missing a true 25 per cent therapeutic improvement, and with the same risk, 50 of the trials could have missed a 50 per cent improvement. Estimates of 90 per cent confidence intervals for the true improvement in each trial showed that in 57 of these "negative" trials, a potential 25 per cent improvement was possible, and 34 of the trials showed a potential 50 per cent improvement. Many of the therapies labeled as "no different from control" in trials using inadequate samples have not received a fair test. Concern for the probability of missing an important therapeutic improvement because of small sample sizes deserves more attention in the planning of clinical trials.

Clinical Trials as Topic↗

PubMed2004

[Quality of methodology and reporting of randomized controlled trials of acupuncture for obesity].

OBJECTIVE: To evaluate the quality of methodology and reporting of randomized controlled trials of acupuncture for obesity worldwide. METHODS: Collecting all the randomized controlled trials of acupuncture for obesity worldwide by systematically searching without language limitation. The quality of methodology and reporting was evaluated by the quality criteria recommended by Cochrane handbook and CONSORT (consolidate standards of reporting trial) and STRICTA (standard for reporting interventions in controlled trials of acupuncture) checklists. RESULTS: Seven randomized controlled trials of acupuncture for obesity were identified. The quality of methodology was graded as "A" in one trial, "B" in two trials and "C" in the other four trials. The reporting quality of the seven trials was graded as "C". CONCLUSIONS: The methodology quality of the randomized controlled trials of acupuncture for obesity was too poor to provide strong evidence for clinical practice, and the poor reporting quality of the trials resulted in inadequate information from the trials.

Acupuncture Therapy↗

PubMed2003

The evolution of the randomized controlled trial and its role in evidence-based decision making.

The randomized controlled trial has been used in medical research for a little over half a century. This manuscript provides an overview of some of the history and evolution of the randomized controlled trial during this period. There exists hierarchies of evidence for therapeutic, diagnostic and prognostic questions, and the randomized controlled trial is at the top of the therapeutic hierarchy. Despite being at the top of the therapeutic hierarchy randomization in itself does not guarantee the trial results approximate the true effect. Issues that result in systematic and nonsystematic deviations from the truth in randomized controlled trials must also be considered. We present a model for evidence-based decision making that includes the following components: the clinical state, patient preferences, research evidence from a range of studies and clinical expertise. We discuss the role of the randomized controlled trial within evidence-based decision making.

Decision Making↗

PubMed1991

Reduced intravascular catheter infection by antibiotic bonding. A prospective, randomized, controlled trial.

We report a prospective, randomized, controlled clinical trial to evaluate the efficacy of antibiotic-bonded catheters in reducing the incidence of intravascular catheter-related infections. Ninety-three central venous catheters and 85 arterial catheters were studied in the surgical intensive care unit. Study catheters were pretreated with the cationic surfactant tridodecylmethylammonium chloride. The anionic antibiotic, cefazolin, was bonded before insertion of the catheters by immersing them in a 50-mg/mL solution. Fourteen percent of the 81 catheters in the control group were infected, compared with 2% of the 97 antibiotic-bonded catheters. Staphylococcus epidermidis was the most common organism obtained. There was no significant difference in the number of colonized or clinically inflamed catheter insertion sites. None of the 100 antibiotic immersion solutions yielded anything on microbiologic culture. We conclude that antibiotic bonding is an efficient, safe, and cost-effective method of reducing intravascular catheter infection in patients who are in intensive care units.

Bacterial Infections↗

PubMed2002

New drugs with novel therapeutic characteristics. Have they been subject to randomized controlled trials?

OBJECTIVE: To determine how many randomized controlled trials on the safety or efficacy of new drugs are published when these drugs are first marketed in Canada, and to determine the quality of the information in those trials. DESIGN: A MEDLINE search was conducted on each drug identified as having novel therapeutic characteristics and first marketed between 1990 and 2000. MAIN OUTCOME MEASURES: Number of trials dealing with the safety or efficacy of each drug published at the time the drug was marketed. Number of patients taking the study drug, length of the trial, and type of control. RESULTS: The number of trials varied substantially. For some drugs, there were more than 20 studies; for others only a single study. Many trials were small and short-term, and used placebo controls. CONCLUSION: Too few trials or inadequate trials on the safety and efficacy of new drugs are published when these drugs are first marketed in Canada. The lack of published trials means that physicians do not know whether results are generalizable to their patients, how to position the drug in relation to other treatments, or whether the drugs have long-term safety and efficacy.

Canada↗

PubMed2005

[A marital-relationship enhancement program for couples: randomized controlled trial].

PURPOSE: This paper reports a randomized controlled trial to investigate the effects of a Marital-relationship enhancement program(MREP) for marital couples. METHODS: Volunteer couples from several well-being centers in Seoul were randomly assigned either to a treatment group (n=36), participating in a MREP based on Gottman's "sound marital house" theory, or to a control group (n=35) receiving no treatment. The content of the MREP was provided to the control group after the research was completed. Data was collected from December 2003 to May 2004 using modified versions of the inventories developed by Gottman on marital satisfaction, positive affect, conflict regulation, and communication barriers. RESULTS: Participants in the experimental group showed significant improvements in marital satisfaction, positive affects, conflict regulation, and communication-barrier scores compared to the control group. CONCLUSION: The present program for marital-relationship enhancement is helpful in enhancing marital relationships and regulating conflict between marital couples and, ultimately, may be useful to prevent divorce.

Adult↗

PubMed1991

Is there an alternative to the randomized controlled trial?

The advantages of the concurrently randomized controlled trial as a device to assess the efficacy of drugs intended for use in the field of psychiatry are reviewed. The importance of "assay sensitivity" is discussed and illustrations of errors that can arise when inferences about efficacy are based upon comparisons that find no difference between experimental and standard treatments are presented. These illustrations are derived from data collected in two different pre-marketing commercial drug development programs. Also discussed is the argument that controlled trials are inappropriate devices to test drug efficacy because of their alleged lack of sensitivity to drug effects.

Humans↗

PubMed2003

Late-starter sites in randomized controlled trials.

In a cohort of 14 randomized controlled trials conducted by the Adult AIDS Clinical Trials Group between 1986 and 1999 with a target sample size of >400 (total enrollment 15,531 patients), we evaluated whether "late-starter" sites can make a meaningful contribution to eventual trial accrual. The sites that started recruiting within 5 months from the time the first patient entered the trial were eventually responsible for over 90% of the total enrollment in 11 of the 14 trials. Across the 14 trials, some sites were consistently among the first to start enrollment, whereas others were routinely among the last. The late-starter sites are unlikely to make important contributions to eventual trial enrollment in large clinical trials conducted by groups with a fixed number of sites. Protracting administrative efforts to add more sites many months after a multicenter trial has started may not be useful to trial accrual.

Acquired Immunodeficiency Syndrome↗

PubMed2005

What have we learned about randomized, controlled trials in neonatal sepsis?

OBJECTIVE: To identify strategies to enable randomized, controlled trials in neonatal sepsis to recognize therapies that increase disability-free survival. METHODS: Rapid literature review. RESULTS: Randomized, controlled trials are the gold standard for testing a therapy because they minimize bias. However, randomized, controlled trials must also minimize random error if they are to detect moderate (and realistic) improvements in rates of disability-free survival reliably. This requires surprisingly large samples (i.e., thousands rather than hundreds). Against this perspective, most neonatal trials have been too small to be conclusive, so most neonatal therapies remain incompletely evaluated. As in specialties like cardiology and obstetrics, achieving reliable trials in neonatal sepsis will require international collaboration, simpler data sets, more cost-effective recruitment strategies, less exclusive criteria for selecting collaborators and patients, and an appreciation by clinicians and data-monitoring committees that substantially greater sample sizes are needed to limit the play of chance. Prospective meta-analysis using individual patient data is a promising strategy. It requires researchers to obtain funding from their national agencies to conduct similar trials according to an agreed protocol with prespecified hypotheses, interventions, power calculations, data sets, and measures of outcome. Prospective meta-analysis combines the methodologic advantages of a single "megatrial" with the practical advantages that financial burdens are spread internationally and different national funding cycles can be more flexibly accommodated. CONCLUSIONS: Prospective meta-analysis using individual patient data is a promising strategy for achieving large-scale, randomized evidence in neonatal sepsis.

Critical Illness↗

PubMedDate not supplied

The randomized controlled trial in studies using biomarkers.

The randomized controlled trial (RCT) is a scientific experiment during which observations on the effects of therapy or a preventive action are conducted by the researcher under rigorous control. The purpose of the experiment is to clear the uncertainties surrounding a clinical/research issue and involves isolating the 'treatment' and 'end result' variables from external influences. RCTs therefore make use of scientific method standards: measuring, which includes the possibility of reproducing observations; controlling factors unconnected to the cause-effect relationship of interest; and the external verification or 'falsification' of the cause-effect relationship. Many RCTs are now including biomarkers to answer scientific questions in a more accurate way. In the present methodological paper, the main aspects involved in the design and conduction of a trial are discussed, with special emphasis on the use of biomarkers. Aspects that are often overlooked by scientists involved in the design of trials include multiple comparisons, subgroup analysis, the duration of the observations, the use of surrogate endpoints, and ethical issues. This review summarizes the main issues that should be addressed in a protocol, and illustrates these with an example.

Biomarkers↗

PubMed1997

Conservative treatment of acute and chronic nonspecific low back pain. A systematic review of randomized controlled trials of the most common interventions.

STUDY DESIGN: A systematic review of randomized controlled trials. OBJECTIVES: To assess the effectiveness of the most common conservative types of treatment for patients with acute and chronic nonspecific low back pain. SUMMARY OF BACKGROUND DATA: Many treatment options for acute and chronic low back pain are available, but little is known about the optimal treatment strategy. METHODS: A rating system was used to assess the strength of the evidence, based on the methodologic quality of the randomized controlled trials, the relevance of the outcome measures, and the consistency of the results. RESULTS: The number of randomized controlled trials identified varied widely with regard to the interventions involved. The scores ranged from 20 to 79 points for acute low back pain and from 19 to 79 points for chronic low back pain on a 100-point scale, indicating the overall poor quality of the trials. Overall, only 28 (35%) randomized controlled trials on acute low back pain and 20 (25%) on chronic low back pain had a methodologic score of 50 or more points, and were considered to be of high quality. Various methodologic flaws were identified. Strong evidence was found for the effectiveness of muscle relaxants and nonsteroidal anti-inflammatory drugs and the ineffectiveness of exercise therapy for acute low back pain; strong evidence also was found for the effectiveness of manipulation, back schools, and exercise therapy for chronic low back pain, especially for short-term effects. CONCLUSIONS: The quality of the design, execution, and reporting of randomized controlled trials should be improved, to establish strong evidence for the effectiveness of the various therapeutic interventions for acute and chronic low back pain.

Acute Disease↗

PubMed2003

Efficacy of a psychoeducative group program for caregivers of demented persons living at home: a randomized controlled trial.

OBJECTIVES: To test the efficacy of a psychoeducative group program for informal caregivers of persons with dementia. METHODS: The study was a multicenter randomized controlled trial. Randomization was stratified according to sex and kinship. Participants randomized to the control group were referred to the traditional support groups. Participants in the study group had fifteen 2-hr weekly sessions focusing on stress appraisal and coping. Eligible participants (primary caregivers of community-dwelling persons with dementia) were blindly assessed before the randomization and after 16 weeks on the following measures: frequency and reactions to behavioral problems (primary outcome), burden, psychological distress, anxiety, perceived social support, and personal efficacy. RESULTS: A total of 158 participants were randomized to the study (n = 79) and control (n = 79) groups in 12 successive waves. Results show that study participants presented a 14% decrease in their reactions to the behavioral problems of the care-receivers as opposed to a 5% decrease in the control group ( p =.04). The frequency of behavior problems also decreased ( p =.06), as did the cross-product frequency/reaction ( p =.02). There was no significant effect on the secondary outcome variables. DISCUSSION: This is one of the first studies showing a significant effect of this type of support group program on the caregivers of participants with dementia.

Aged↗

PubMed2001

Periradicular infiltration for sciatica: a randomized controlled trial.

STUDY DESIGN: A randomized, double-blind trial was conducted. OBJECTIVES: To test the efficacy of periradicular corticosteroid injection for sciatica. SUMMARY OF BACKGROUND DATA: The efficacy of epidural corticosteroids for sciatica is controversial. Periradicular infiltration is a targeted technique, but there are no randomized controlled trials of its efficacy. METHODS: In this study 160 consecutive, eligible patients with sciatica who had unilateral symptoms of 1 to 6 months duration, and who never underwent surgery were randomized for double-blind injection with methylprednisolone bupivacaine combination or saline. Objective and self-reported outcome parameters and costs were recorded at baseline, at 2 and 4 weeks, at 3 and 6 months, and at 1 year. RESULTS: Recovery was better in the steroid group at 2 weeks for leg pain (P = 0.02), straight leg raising (P = 0.03), lumbar flexion (P = 0.05), and patient satisfaction (P = 0.03). Back pain was significantly lower in the saline group at 3 and 6 months (P = 0.03 and 0.002, respectively), and leg pain at 6 months (13.5, P = 0.02). Sick leaves and medical costs were similar for both treatments, except for cost of therapy visits and drugs at 4 weeks, which were in favor of the steroid injection (P = 0.05 and 0.005, respectively). By 1 year, 18 patients in the steroid group and 15 in the saline group underwent surgery. CONCLUSIONS: Improvement during the follow-up period was found in both the methylprednisolone and saline groups. The combination of methylprednisolone and bupivacaine seems to have a short-term effect, but at 3 and 6 months, the steroid group seems to experience a "rebound" phenomenon.

Adult↗

PubMed2006

Short-term efficacy of intravenous pulse glucocorticoids in acute discogenic sciatica. A randomized controlled trial.

STUDY DESIGN: Double-blinded randomized controlled trial. OBJECTIVE: To test the short-term efficacy of a single intravenous (IV) pulse of glucocorticoids on the symptoms of acute discogenic sciatica. SUMMARY OF BACKGROUND DATA: The use of glucocorticoids in the treatment of acute discogenic sciatica is controversial. A potential advantage of the IV pulse therapy is the ability to distribute high glucocorticoid concentrations to the area surrounding the prolapsed disc without the risks and inconveniences of an epidural injection. METHODS: Patients with acute sciatica (<6-week duration) of radiologically confirmed discogenic origin were randomized to receive either a single IV bolus of 500 mg of methylprednisolone or placebo. Clinical evaluation was performed in a double-blind manner on days 0, 1, 2, 3, 10, and 30. The primary outcome was reduction in sciatic leg pain during the first 3 days following the infusion; secondary outcomes were reduction in low back pain, global pain, functional disability, and signs of radicular irritation. The analysis was performed on an intent-to-treat basis using a longitudinal regression model for repeated measures. RESULTS: A total of 65 patients were randomized, and 60 completed the treatment and the follow-up assessments. A single IV bolus of glucocorticoids provided significant improvement in sciatic leg pain (P = 0.04) within the first 3 days. However, the effect size was small, and the improvement did not persist. IV glucocorticoids had no effect on functional disability or clinical signs of radicular irritation. CONCLUSIONS: Although an IV bolus of glucocorticoids provides a short-term improvement in leg pain in patients with acute discogenic sciatica, its effects are transient and have small magnitude.

Double-Blind Method↗

PubMed2006

[The term breech trial: the rise and fall of a randomized controlled trial--a critical survey].

Six years after publication of the results of the first international randomized controlled trial with the main question which mode of delivery is the best for term breech babies, there are increasing concerns about the validity of the study data concluding caesarean delivery was safer for breech babies. In January 2006 published article in the American Journal of Obstetrics and Gynecology the data of the study has been analysed again. The author comes to the conclusion that because of mistakes in the study design the results are unreliable and that the study group should withdraw the recommendations. Furthermore in his article he quotes from the study and emphasizes the mistakes.

Breech Presentation↗