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Results for “Randomized trial”

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PubMed2001

Balance in cluster randomized trials.

This paper explores the role of balancing covariates between treatment groups in the design of cluster randomized trials. General expressions are obtained for two criteria to evaluate designs for parallel group studies with two treatments. The first is the variance of the estimated treatment effect and the second is the extent to which the estimated treatment effect is changed by adjusting for covariates. It is argued that the second of these is more important for cluster randomized trials. Methods of obtaining balanced designs from covariates which are available at the start of a study are proposed. An imbalance measure is used to compare the extent to which designs balance important covariates between the arms of a trial. Several approaches to selecting a well balanced design are possible. A method that randomly selects one member from the class of designs with acceptable bias will allow randomization inference as well as model-based inference. The methods are illustrated with data from a trial of school-based sex education.

Adolescent↗

PubMed2003

Impact of patient information booklet on treatment decision--a randomized trial among women with heavy menstruation.

OBJECTIVE: Does a patient information booklet influence treatment for menorrhagia? DESIGN: Randomized trial and a pre-trial prospective cohort study. SETTING: Gynaecology outpatient clinics in 14 Finnish hospitals. PARTICIPANTS: A total of 363 (randomized trial) plus 206 (cohort study) patients with menorrhagia. INTERVENTION: An information booklet about menorrhagia and treatment options, mailed before the first visit to the outpatient clinic. MAIN OUTCOME MEASURES: Distribution of treatment modalities, knowledge about treatment options, satisfaction with communication with personnel and anxiety. RESULTS: Treatment decision within 3 months was made more often in the intervention group than in the control group (96% and 89% respectively, P = 0.02). Oral medication was more frequently chosen, and newly introduced treatments (minor surgery, hormonal intrauterine system) were less frequently used in the intervention group (at 3-month follow-up 21% and 29%, respectively). The differences persisted at the 12-month follow-up. In the pre-trial group, new treatment methods were less frequently chosen and used than in the control group. Additional information did not increase the number of surgical procedures used, improve knowledge, or influence satisfaction or anxiety. CONCLUSIONS: Additional information led to an increase in specific treatment decisions and changed the distribution of used treatments without increasing the number of surgical procedures. The study suggests that well-informed women adopting an active role may counteract physicians' emphasis on newly introduced treatments.

Adult↗

PubMed2001

Effect of continuous versus dichotomous outcome variables on study power when sample sizes of orthopaedic randomized trials are small.

It is often not feasible to conduct large trials in orthopaedic surgery. Therefore, surgeons must identify strategies to optimize the statistical power of their smaller studies. The aim of this study was to compare study power in randomized trials with continuous versus dichotomous outcome variables. We performed a systematic review of the literature to identify randomized trials in orthopaedic trauma. Of these, we examined only those trials with small sample sizes (50 patients or less). The outcomes in each eligible study were categorized as continuous or dichotomous. Standard power calculations were performed for each study, and comparisons were made between continuous and dichotomous outcome variables. We identified 196 randomized trials in orthopaedic trauma. Of these, 76 trials had a sample size of 50 patients or fewer (29 trials with continuous outcomes, 47 trials with dichotomous outcomes). Studies that reported continuous outcomes had a significantly higher mean power than those that reported dichotomous variables (power 49% vs 38%, p=0.042). Twice as many trials with continuous outcome variables reached acceptable levels of study power (i.e. >80% power) when compared with trials with dichotomous variables (37% vs 18.6%, p=0.04). When orthopaedic surgeons anticipate small sample sizes for their study, they can optimize their study's statistical power by choosing a continuous outcome variable.

Cluster Analysis↗

PubMed2004

Randomized trial of Rotational Atherectomy Versus Balloon Angioplasty for Diffuse In-stent Restenosis (ROSTER).

BACKGROUND: Various autopsy and intravascular ultrasound (IVUS) studies have shown neointimal proliferation as the main mechanism of in-stent restenosis (ISR) responsible for >95% of luminal narrowing while stent struts are not compressed. ISR of diffuse type has a high incidence of recurrence (up to 70%) after balloon angioplasty (PTCA). Tissue ablation with percutaneous rotational coronary atherectomy (PRCA) may be more efficacious compared to tissue compression or extrusion after PTCA for the interventional treatment of diffuse ISR. METHODS: The Rotational Atherectomy Versus Balloon Angioplasty for Diffuse In-Stent Restenosis (ROSTER) trial is a single-center, randomized trial comparing PRCA to PTCA (both with IVUS guidance) in the treatment of diffuse ISR in 200 patients. In the PRCA group (n = 100), rotablation was performed using a burr-to-artery ratio >0.7 followed by adjunctive balloon dilatation at low pressure (4-6 atm). In the PTCA group (n = 100), high-pressure (>12 atm) balloon dilatation was performed using an optimal size balloon. The study's primary end point was target lesion revascularization (TLR) at 9 months and secondary end points included clinical events at 1 year and angiographic restenosis in a substudy of the last 75 patients enrolled. RESULTS: Baseline clinical and angiographic variables were comparable between the 2 groups with similar procedural and angiographic success, but a higher rate of repeat stenting occurred in the PTCA group (31% vs 10%; P <.001). Although the angiographic acute luminal gain was similar between the 2 groups, IVUS analysis revealed lower residual intimal hyperplasia area after PRCA versus PTCA (2.1 +/- 0.9 mm2 vs. 3.3 +/- 1.8 mm2; P =.005). At a mean follow-up of 12 +/- 2 months, there were 2 deaths, 3 myocardial infarctions, and 3 coronary artery bypass graft procedures in each group. TLR incidence was 32% in the PRCA group and 45% in the PTCA group (P =.042), with a similar trend noted in the angiographic substudy. CONCLUSION: The ROSTER trial for diffuse ISR revealed both PRCA and PTCA to be safe and effective, but PRCA resulted in less residual intimal hyperplasia, lower repeat stent use, and decreased TLR.

Aged↗

PubMed2002

Recruitment strategies in a cluster randomized trial--cost implications.

The presence of a non-zero intracluster correlation coefficient in cluster randomized trial data has well-known statistical implications for trial design, in particular, inflating the required sample size for given specifications. However, problems in recruitment are common in such trials and there may be different costs of recruitment resulting from different recruitment strategies. Examples of how such differences arise are taken from cluster randomized trials and more intuitive methods of describing clustering are summarized which, in conjunction with such cost issues, may provide a framework that enables triallists to consider explicitly the trade-off between power and cost that is often inherent in such trials.

Adolescent↗

PubMed2000

Cluster randomized trials in general (family) practice research.

Cluster randomized trials are increasingly common in general practice (family medicine). This paper will consider the design and analysis of such trials and emphasize the similarities and differences with trials in education, heath promotion and public health. Issues discussed are the estimation and range of values of the intra-cluster correlation coefficient found in general practice, and the associated sample size problems. There are problems with widely varying numbers of subjects per cluster, which leads to planning and analysis difficulties. Ethical issues in these trials, and considerations such as the principle of intention to treat are also considered. An example of the type of analysis available for a continuous outcome variable is given, and the available software is summarized briefly.

Biometry↗

PubMedDate not supplied

Interferon and ursodeoxycholic acid combined therapy in chronic viral C hepatitis: controlled randomized trial in 203 patients.

AIMS: This prospective randomized trial was carried out in order to determine whether the long-term administration of ursodeoxycholic acid after discontinuation of interferon had any beneficial effect on the clinical course of hepatitis C virus infection. METHODS: Enrolled in the study were 203 patients with chronic active hepatitis C. They were all given: interferon alpha-2a (3 MU subcutaneously thrice a week) and ursodeoxycholic acid (10 mg/kg/day) for 9 months. At month 9, biochemical responders only were randomized into ursodeoxycholic acid treatment or placebo for 12 additional months (double blind study). RESULTS: At the end of interferon therapy, 71 patients (37%) were virological responders and 107 (56%) patients were biochemical responders and were randomized: 54 into the ursodeoxycholic acid group and 53 into the placebo group. Sustained response was evaluated 12 months after withdrawal of interferon. Sustained biochemical and virological responses were, respectively, 30% and 22% in the ursodeoxycholic acid group and 46% and 32% in the placebo group, which did not significantly differ. Histological evolution of fibrosis and necrotic inflammatory activity were similar in the two groups. CONCLUSION: Continuation of ursodeoxycholic acid therapy after withdrawal of interferon in patients with end-of-treatment response did not result in any significant improvement either in the maintenance of response to interferon or in liver histology.

Adolescent↗

PubMed1984

A randomized trial of 48 hours of prophylactic cefotaxime versus single dose in transurethral prostatic surgery.

A previous randomized trial from this department demonstrated that there was significant reduction in morbidity and post-operative bacteriuria when men undergoing transurethral prostatectomy were given a prophylactic perioperative regimen of 48 h of cefotaxime compared with a no treatment control group. In this paper we report the results of a new randomized trial to determine whether a single dose of cefotaxime given with the induction of anaesthesia would be of equal efficacy to the previous 48 h regimen. We also investigated the ward bacterial flora for cefotaxime resistance before and during the trial. The 48 h regimen was significantly superior to the single dose in terms of the number of men who developed post operative complications and there was also a small but significant reduction in post-operative hospital stay. Forty-eight hours of prophylaxis covers the normal time of post-operative urethral catheterization and this may explain our findings. There was no evidence of emergence of cefotaxime resistant strains.

Bacteriuria↗

PubMed2004

Cluster randomized trial of an active, multifaceted information dissemination intervention based on The WHO Reproductive health library to change obstetric practices: methods and design issues [ISRCTN14055385].

BACKGROUND: Effective strategies for implementing best practices in low and middle income countries are needed. RHL is an annually updated electronic publication containing Cochrane systematic reviews, commentaries and practical recommendations on how to implement evidence-based practices. We are conducting a trial to evaluate the improvement in obstetric practices using an active dissemination strategy to promote uptake of recommendations in The WHO Reproductive Health Library (RHL). METHODS: A cluster randomized trial to improve obstetric practices in 40 hospitals in Mexico and Thailand is conducted. The trial uses a stratified random allocation based on country, size and type of hospitals. The core intervention consists of three interactive workshops delivered over a period of six months. The main outcome measures are changes in clinical practices that are recommended in RHL measured approximately a year after the first workshop. RESULTS: The design and implementation of a complex intervention using a cluster randomized trial design are presented. CONCLUSION: Designing the intervention, choosing outcome variables and implementing the protocol in two diverse settings has been a time-consuming and challenging process. We hope that sharing this experience will help others planning similar projects and improve our ability to implement change.

Female↗

PubMed2003

Radix Sophorae flavescentis for chronic hepatitis B: a systematic review of randomized trials.

To evaluate the effects of radix Sophorae fiavescentis for chronic hepatitis B, a systematic review of randomized clinical trials was conducted. Randomized trials comparing extract of radix Sophorae flavescentis versus placebo, no intervention, non-specific treatment, other active medicines, or interferon for chronic hepatitis B were identified by electronic and manual searches. Trials of Sophorae herb plus other drugs versus other drugs alone were also included. No blinding and language limitations were applied. The methodological quality of trials was assessed by the Jadad scale plus allocation concealment. Meta-analysis was performed where data was available. Twenty-two randomized trials (n = 2409) were included. Methodological quality of the trials was generally low. The combined results showed that matrine (aqueous extract of Sophorae flavescentis) had antiviral activity, positive liver biochemical effects, and improved symptoms and signs compared with non-specific treatment and other herbal medicines. The combination of matrine and interferon-alpha (IFN-alpha), thymosin, or basic treatment showed better effects on viral and liver biochemical responses. The antiviral and biochemical responses were not significantly different between matrine and IFN-alpha. No serious adverse event was reported. Based on the review, Sophorae flavescentis extract (matrine) may have antiviral activity and positive effects on liver biochemistry in chronic hepatitis B. However, the evidence is not sufficient to recommend matrine for routine clinical use due to the generally low methodological quality of the studies. Further rigorous trials are needed.

Alkaloids↗

PubMed1995

The efficacy of a consumer case management team: 2-year outcomes of a randomized trial.

This article reports the results of a randomized trial of a team of case managers who are mental health consumers compared to a team of nonconsumer. Using a repeated measures MANOVA design, consumer case managers were found to be as effective as a team of nonconsumer case managers in maintaining the stability of severely mentally disabled clients served over a 2-year period. Implications for the employment of consumers in mental health services and the vocational capacity of persons with mental illness are discussed.

Administrative Personnel↗

PubMed1996

Rapid course radiation therapy vs. more standard treatment: a randomized trial for bone metastases.

PURPOSE: In a prospective randomized trial we examined whether radiotherapy of painful bone metastases can be shortened using larger single doses without impairing effectivity. METHODS AND MATERIALS: One hundred patients with painful bone metastases having no prior surgical intervention or treatment with x-ray therapy and had a median follow-up of 12 months were analyzed. The primary tumor was located in the breast in 43%, in the lung in 24%, and in the prostate in 14%. The most frequent sites of metastases were the pelvis (31%), the vertebral column (30%), and the ribs (20%). Further percentages of sites were: lower extremity 11%, upper extremity 6%, and skull 2%. Fifty-one patients received a short course radiotherapy with a total dose of 20 Gy in 1 week (daily dose 4 Gy), and 49 patients received 30 Gy in 3 weeks (daily dose 2 Gy). RESULTS: There were no significant differences in frequency, duration of pain relief, improvement of mobility, recalcification, frequency of pathologic fractures nor survival. There was a light trend favoring 30 Gy in frequency of pain relief and recalcification. Survival was mostly influenced by primary tumor site, Karnofsky performance status, and possibly by the response to radiotherapy (pain relief). CONCLUSIONS: Because of the very short life expectancy of patients with metastatic bone disease, we now use 20 Gy in 1 week as our standard to reduce hospital stay.

Adult↗

PubMed1999

Teaching coping skills enhances quality of life more than peer support: results of a randomized trial with multiple sclerosis patients.

This 2-year randomized trial of multiple sclerosis patients compared a coping skills group (n = 64) with peer telephone support (n = 68). Growth curve analyses that adjusted for neurological deterioration and gender revealed that the coping skills intervention yielded gains in psychosocial role performance, coping behavior, and numerous aspects of well-being. In contrast, the peer support intervention increased external health locus of control but did not influence psychosocial role performance or well-being. Subgroup analyses revealed that patients with affective problems were more likely to benefit from the peer support intervention than the coping skills group in terms of reported depression, anxiety, use of avoidant coping, and some aspects of well-being. The coping group is discussed as a vehicle for facilitating response shift, helping patients to change their internal referents, their conceptualization of quality of life, and their priorities.

Adaptation, Psychological↗

PubMed2001

Adjuvant high-dose medroxyprogesterone acetate for early breast cancer: 13 years update in a multicentre randomized trial.

The authors updated their report on a randomized trial initiated in 1982 comparing, in early breast cancer, high-dose IM Medroxyprogesterone acetate (HD-MPA) adjuvant hormonotherapy during 6 months with no hormonotherapy; node-positive patients also received 6 courses of IV CMF (day 1, day 8; q.4 weeks). 246 node-negative (NN) and 270 node-positive (NP) patients had been followed for a median duration of 13 years. Previous results were confirmed in this analysis on mature data. In NN patients, relapse-free survival (RFS) was improved in the adjuvant hormonotherapy arm, regardless of age while overall survival (OAS) was also increased in younger (less then 50 years) patients. In the whole group of NP patients, no difference was seen regarding RFS or OAS. However, an age-dependant opposite effect was observed: younger patients (< 50) experienced a worse and significant outcome of relapse-free and overall survivals when receiving adjuvant HD-MPA while older patients (> or = 50) enjoyed a significant improvement of their relapse-free survival. For both NN and NP patients, differences in overall survivals observed in older women with a shorter follow-up, were no longer detected.

Age Factors↗

PubMed1991

Postoperative irrigation-suction drainage after pelvic colonic surgery. A prospective randomized trial.

A 2-year randomized prospective clinical trial was undertaken to determine whether postoperative irrigation of the pelvis would result in a decreased incidence of local septic complications. Two hundred consecutive patients undergoing low pelvic procedures with rectal resection and entry of the presacral space by a single surgeon, were randomized. In the irrigation group, two of four presacral sump drains were placed to low intermittent suction and the remaining sumps infused continuously with saline until the effluent was clear. In the drainage alone group, all four presacral sump drains were placed to suction. Drains were removed when drainage was less than 50 ml/24 hours. Perioperative antibiotics and bowel preparation were identical. Postoperative complications included pelvic abscess (n = 7), anastomotic leak/cuff sinus (n = 11), abdominal wound infection (n = 19), and perineal wound infection (n = 5). Postoperative irrigation of the pelvis did not result in a reduction in the overall rate of local pelvic septic complications. Positive intraoperative presacral cultures, the presence of anaerobes in the presacral space, and duration of pelvic drainage had no effect on the development of pelvic sepsis.

Abscess↗

PubMed1992

The postmastectomy pain syndrome and topical capsaicin: a randomized trial.

This paper describes a randomized parallel trial of topical 0.075% capsaicin versus vehicle (placebo) in the postmastectomy pain syndrome (PMPS). The study was double-blind in design; however, this was compromised by the burning sensation induced by capsaicin. We could not demonstrate a significant difference in the visual analogue scale (VAS) for steady pain although a trend was present. A significant difference was found, however, in the VAS for jabbing pain, in category pain severity scales, and in overall pain relief scales in favour of capsaicin. Five of 13 patients on capsaicin were categorized as good-to-excellent responses with 8 (62%) having 50% or greater improvement. Only 1 of 10 cases had a good response to vehicle with 3 rated as 50% or better.

Administration, Topical↗

PubMedDate not supplied

Effectiveness of a home-based exercise intervention for HIV-infected adults: a randomized trial.

The authors conducted a randomized controlled trial to assess the impact of a 15-week (20 minutes three times per week) home-based aerobic exercise intervention versus usual care on the physical endurance, immune status, and self-reported health status of 99 HIV-infected adults. In the exercise group, there was no improvement in physical endurance or health-related quality of life (HRQOL), except in the Medical Outcomes Study-HIV Health Survey Overall Health subscale (difference = 12.1, 95% confidence interval = 2.0-22.2, p = .02). Although physical endurance levels were maintained at baseline levels in the intervention group and declined in the control group, differences between the groups were small and not significant. There were also no significant changes in CD4+ T-lymphocyte counts. Exercise appears to be safe in HIV-infected patients. Improvements in physical endurance and HRQOL might result if the exercise protocol is longer or progressive. Further research is needed to establish guidelines for exercise in patients on highly active antiretroviral therapy.

Adult↗

PubMed2005

Locoregional radiation therapy in patients with high-risk breast cancer receiving adjuvant chemotherapy: 20-year results of the British Columbia randomized trial.

BACKGROUND: The British Columbia randomized radiation trial was designed to determine the survival impact of locoregional radiation therapy in premenopausal patients with lymph node-positive breast cancer treated by modified radical mastectomy and adjuvant chemotherapy. Three hundred eighteen patients were assigned to receive no further therapy or radiation therapy (37.5 Gy in 16 fractions). Previous analysis at the 15-year follow-up showed that radiation therapy was associated with a statistically significant improvement in breast cancer survival but that improvement in overall survival was of only borderline statistical significance. We report the analysis of data from the 20-year follow-up. METHODS: Survival was analyzed by the Kaplan-Meier method. Relative risk estimates were calculated by the Wald test from the proportional hazards regression model. All statistical tests were two-sided. RESULTS: At the 20 year follow up (median follow up for live patients: 249 months) chemotherapy and radiation therapy, compared with chemotherapy alone, were associated with a statistically significant improvement in all end points analyzed, including survival free of isolated locoregional recurrences (74% versus 90%, respectively; relative risk [RR] = 0.36, 95% confidence interval [CI] = 0.18 to 0.71; P = .002), systemic relapse-free survival (31% versus 48%; RR = 0.66, 95% CI = 0.49 to 0.88; P = .004), breast cancer-free survival (48% versus 30%; RR = 0.63, 95% CI = 0.47 to 0.83; P = .001), event-free survival (35% versus 25%; RR = 0.70, 95% CI = 0.54 to 0.92; P = .009), breast cancer-specific survival (53% versus 38%; RR = 0.67, 95% CI = 0.49 to 0.90; P = .008), and, in contrast to the 15-year follow-up results, overall survival (47% versus 37%; RR = 0.73, 95% CI = 0.55 to 0.98; P = .03). Long-term toxicities, including cardiac deaths (1.8% versus 0.6%), were minimal for both arms. CONCLUSION: For patients with high-risk breast cancer treated with modified radical mastectomy, treatment with radiation therapy (schedule of 16 fractions) and adjuvant chemotherapy leads to better survival outcomes than chemotherapy alone, and it is well tolerated, with acceptable long-term toxicity.

Antineoplastic Combined Chemotherapy Protocols↗