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Results for “Randomized trial”

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PubMed1990

Improving family functioning after cardiac surgery: a randomized trial.

As part of a randomized clinical trial of in-hospital and postdischarge nursing interventions designed to facilitate the individual patient's recovery and improve the family's functioning after cardiac surgery, we followed 67 patient-spouse pairs for 6 months after surgery. Family health was appraised by using three pencil and paper measurements: the Family APGAR, the Locke-Wallace Marital Adjustment Scale, and the Family Inventory of Resources for Management. Mixed-effects analysis of variance did not detect differences for the main effect of intervention group; however, the main effect of time was significant for both patients' and spouses' APGAR scores and for patients' Marital Adjustment Scale scores, suggesting a pattern of response during recovery from cardiac surgery.

Adaptation, Psychological↗

PubMed2002

Chemotherapy for recurrent epithelial ovarian cancer previously treated with platinum--a systematic review of the evidence from randomized trials.

PURPOSE: To evaluate the chemotherapeutic options for women with recurrent epithelial ovarian cancer who have received platinum-based chemotherapy. METHODS: A systematic search of the Medline, CancerLit and Cochrane Library databases was performed for the period from 1984 to June 2001 to find randomized trials comparing second- or higher-line chemotherapy regimens in patients with recurrent platinum-pretreated epithelial ovarian cancer. RESULTS: Seven randomized trials have failed to demonstrate the clear superiority of any one chemotherapy regimen in terms of improvements in long-term survival, quality of life or response rate. One trial detected a statistically significant difference between treatments in progression-free survival, which was longer with cyclophosphamide/doxorubicin/cisplatin than with paclitaxel in women with platinum-sensitive ovarian cancer. Another trial did not show a difference between liposomal doxorubicin and topotecan overall in women with recurrent ovarian cancer but a subgroup analysis detected a significant survival advantage for liposomal doxorubicin over topotecan in women with platinum-sensitive disease. CONCLUSION: The evidence available does not support firm conclusions about the preferred chemotherapy regimen for recurrent ovarian cancer. Randomized trials that compare new drugs with current standard treatments are needed.

Antineoplastic Agents↗

PubMed1997

Quantitative overview of randomized trials of amiodarone to prevent sudden cardiac death.

BACKGROUND: Some randomized clinical trials of amiodarone therapy to prevent sudden cardiac death have had positive results and others have had negative results, but all were relatively small. This meta-analysis aimed to pool all trials to assess the effect of amiodarone on mortality and the impact of differences in patient population and study design on trial outcomes. METHODS AND RESULTS: Fifteen randomized trials were identified, and outcome measures were combined by use of a random effects model. The effect of patient population and study design on total mortality was assessed by use of a hierarchical Bayes model. Amiodarone reduced total mortality by 19% (confidence limits, 6% to 31%; P<.01), with somewhat greater reductions in cardiac mortality (23%, P<.001) and sudden death (30%, P<.001). Mortality reductions were similar in trials enrolling patients after myocardial infarction (21%), with left ventricular dysfunction (22%), and after cardiac arrest (25%). There was a trend toward greater risk reduction in trials requiring evidence of ventricular ectopy (25%) than in the remaining trials (10%). The trials using placebo controls had considerably less risk reduction (10%) than trials with active controls (27%) or usual care controls (42%, posterior odds <0.02). CONCLUSIONS: Amiodarone reduced total mortality by 10% to 19% in patients at risk of sudden cardiac death. Amiodarone reduced risk similarly in patients after myocardial infarction, with heart failure, or with clinically evident arrhythmia. The apparent inconsistencies among results of randomized trials appear to be due to small sample sizes and the type of control group used, not the type of patient enrolled.

Aged↗

PubMed2001

Methodological considerations on the design and analysis of an equivalence stratified cluster randomization trial.

The World Health Organization and collaborating institutions in four developing countries have conducted a multi-centre randomized controlled trial, in which clinics were allocated at random to two antenatal care (ANC) models. These were the standard 'Western' ANC model and a 'new' ANC model consisting of tests, clinical procedures and follow-up actions scientifically demonstrated to be effective in improving maternal and newborn outcomes. The two models were compared using the equivalence approach. This paper discusses the implications of the equivalence approach in the sample size calculation, analysis and interpretation of results of this cluster randomized trial. It reviews the ethical aspects regarding informed consent, concluding that the Zelen design has a place in cluster randomization trials. It describes the estimation of the intracluster correlation coefficient (ICC) in a stratified cluster randomized trial using two methods and reports estimates of the ICC obtained for many maternal, newborn and perinatal outcomes. Finally, it discusses analytical problems that arose: issues encountered using a composite index, heterogeneity of the intervention effect across sites, the choice of the method of analysis and the importance of efficacy analyses. The choice of the clustered Woolf estimator and the generalized estimating equations (GEE) as the methods of analysis applied is discussed.

Adult↗

PubMed2002

Percutaneous coronary intervention versus repeat bypass surgery for patients with medically refractory myocardial ischemia: AWESOME randomized trial and registry experience with post-CABG patients.

OBJECTIVES: This report compares long-term percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) survival among post-CABG patients included in the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) randomized trial and prospective registry. BACKGROUND: Repeat CABG surgery is associated with a higher risk of mortality than first-time CABG. The AWESOME is the first randomized trial comparing CABG with PCI to include post-CABG patients. METHODS: Over a five-year period (1995 to 2000), patients at 16 hospitals were screened to identify a cohort of 2,431 individuals who had medically refractory myocardial ischemia and at least one of five high-risk factors. There were 454 patients in the randomized trial, of whom 142 had prior CABG. In the physician-directed registry of 1,650 patients, 719 had prior CABG. Of the 327 patient-choice registry patients, 119 had at least one prior CABG. The CABG and PCI survivals for the three groups were compared using Kaplan-Meier curves and log-rank tests. RESULTS: The CABG and PCI three-year survival rates were 73% and 76% respectively for the 142 randomized patients (75 and 67 patients) (log-rank = NS). In the physician-directed registry, 155 patients were assigned to reoperation and 357 to PCI (207 received medical therapy); 36-month survivals were 71% and 77% respectively (log-rank = NS). In the patient-choice registry, 32 patients chose reoperation and 74 chose PCI (13 received medical therapy); 36-month survivals were 65% and 86% respectively (log-rank test p = 0.01). CONCLUSIONS: Percutaneous coronary intervention is preferable to CABG for many post-CABG patients.

Aged↗

PubMed1996

Randomized trials in single subjects: the N of 1 study.

Large-scale randomized trials are not available for all disorders, and conventional "trials of therapy" are susceptible to bias. Randomized controlled trials (RCTs) in individual patients (N of 1 RCTs) may provide a solution. In an N of 1 RCT, a patient receives treatments in pairs (one period of the experimental therapy and one period of either an alternative treatment or placebo, in random order), both patient and clinician are kept blind to allocation, and treatment targets are monitored. This type of RCT is useful in chronic, stable conditions in which the proposed treatment has a short half-life. Treatment targets usually include quantitative measurement of symptoms tracked through patient diaries. Pairs of treatment periods are continued until effectiveness is proved or refuted. The N of 1 RCT is potentially of great use in psychopharmacology and in drug development. The practical approach presented here will allow clinicians to conduct their own N of 1 RCTs.

Humans↗

PubMed2006

Ribavirin monotherapy for chronic hepatitis C infection: a Cochrane Hepato-Biliary Group systematic review and meta-analysis of randomized trials.

OBJECTIVES: Adding ribavirin to interferon improves treatment response for patients with chronic hepatitis C, but the effects of ribavirin monotherapy are unclear. We conducted a systematic review to assess the benefits and harms of ribavirin monotherapy for patients with chronic hepatitis C. METHODS: Randomized trials were identified through the Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Library, MEDLINE, and EMBASE (last search May 2005). The primary outcomes were sustained virological response (loss of HCV RNA) and liver-related morbidity plus all-cause mortality. Secondary outcomes included end-of-treatment virological response, biochemical response (normalization of transaminases), histological response, and adverse events. RESULTS: We included 11 randomized trials with 521 patients. Ten trials had unclear control of bias. Ribavirin had no significant effect on sustained (risk difference (RD), 0%; 95% confidence intervals (CI), -2% to 3%) or end-of-treatment virological response (RD, 0%; 95% CI, -3% to 3%). Ribavirin had no significant effect on liver-related morbidity plus mortality (RD, 0%; 95% CI, -2% to 3%). Ribavirin significantly improved histological response and end-of-treatment biochemical response, but not sustained biochemical response. Ribavirin significantly increased the risk of anemia and treatment discontinuation. CONCLUSIONS: We found no evidence to support ribavirin monotherapy for patients with chronic hepatitis C, but trials were small and type II errors cannot be excluded. Patients intolerant to interferon should not continue treatment with ribavirin alone outside randomized trials.

Antiviral Agents↗

PubMedDate not supplied

Hormone replacement therapy and coronary heart disease: results of randomized trials.

A number of lines of evidence have suggested that postmenopausal hormone replacement therapy might be useful in the primary and secondary prevention of coronary heart disease (CHD). Data from recent randomized trials are consistent in showing no overall benefit of hormone replacement therapy as a continuous combined regimen of estrogen and a progestin (PERT) in preventing the development of CHD or preventing recurrent events or progression of atherosclerosis. The randomized trials also raise questions about hormone replacement therapy in the form of estrogen alone (ERT) for prevention of CHD and CHD recurrence. Other interventions to prevent CHD and decrease morbidity and mortality in women with established disease have a strong evidence base. Hormone replacement therapy should not be recommended to prevent CHD or CHD recurrence until and unless data from randomized trials establish this as a benefit.

Age Factors↗

PubMed2002

The quality of reporting of randomized trials in the Journal of Bone and Joint Surgery from 1988 through 2000.

BACKGROUND: The purpose of this study was threefold: (1) to determine the scientific quality of published randomized trials in the American Volume of The Journal of Bone and Joint Surgery from 1988 through 2000, (2) to identify predictors of study quality, and (3) to evaluate inter-rater agreement in the scoring of study quality with use of a simple scale. METHODS: Hand searches of The Journal of Bone and Joint Surgery were conducted in duplicate to identify randomized clinical trials. Of 2468 studies identified, seventy-two (2.9%) met all eligibility criteria. Two investigators each assessed the quality of the study under blinded conditions and abstracted relevant data. RESULTS: The mean score (and standard error) for the quality of the seventy-two randomized trials was 68.1% plus minus 1.6%; 60% (forty-three) scored <75%. Drug trials had a significantly higher mean quality score than did surgical trials (72.8% compared with 63.9%, p < 0.05). Regression analysis revealed that cited affiliation with an epidemiology department and cited funding were associated with higher quality scores. Failure to conceal randomization, to blind outcome assessors, and to describe why patients were excluded resulted in significantly lower quality scores (p < 0.05), more than the 5% decrease expected by removal of each item. A priori calculations of sample size were rarely performed in the reviewed studies, and only 2% of the studies with negative results included a post hoc power analysis. The Detsky quality scale met accepted standards of interobserver reliability (kappa, 0.87; 95% confidence interval, 0.70 to 0.95). CONCLUSIONS: Few studies published in The Journal of Bone and Joint Surgery were randomized trials. More than half of the trials were limited by a lack of concealed randomization, lack of blinding of outcome assessors, or failure to report reasons for excluding patients. Application of standardized guidelines for the reporting of clinical trials in orthopaedics should improve quality.

Humans↗

PubMed2001

Sentinel node dissection in early-stage breast cancer: ongoing prospective randomized trials in the USA.

One of the most important advances in the surgical treatment of early-stage breast cancer has been the introduction of sentinel lymph node dissection as an alternative to routine axillary node dissection. This minimally invasive procedure may reduce the morbidity of surgical treatment and improve staging of the axillary lymph node basin. Over the last 5 to 7 years, numerous institutions have published their sentinel node identification rates, false-negative events, optimal techniques, and learning curves. Many of these issues need confirmation in a prospective multicentered fashion and other issues such as survival and comparative toxicities require prospective randomized trials. Two prospective randomized trials using sentinel node biopsy have been implemented in the United States: the NSABP B-32 trial and the ACOSOG Z0010/Z0011 trials. Design, hypotheses, and rationale for these trials are discussed.

Axilla↗

PubMed1996

5-Fluorouracil, epirubicin, and mitomycin C versus 5-fluorouracil, epirubicin, mitomycin C, and leucovorin in advanced gastric carcinoma. A randomized trial.

Leucovorin (LV) enhances the activity of 5-fluorouracil (5FU). Based on these data, we performed a randomized trial with 5FU, epirubicin (EPI), mitomycin C(MMC) with/ without LV in advanced gastric cancer (AGC). The purpose of our study was to investigate if the addition of LV improved the response rate of the combination 5FU EPI, MMC (FEM) over FEM. From January 1988 until April 1994, 88 patients with recurrent or metastatic AGC were randomly received 5FU, EPI, MMC with (group A) or without (group B) LV. Between the two arms of the study no difference was noticed in sex, performance status, primary site of tumor, and lymph node metastases. Therapy included group A (5FU 600 mg/m2/day, i.v. bolus, on days 1, 8, 29, 36, and EPI 45 mg/m2/day, i.v. bolus, on days 1 and 29, MMC 10 mg/m2/day, i.v. bolus, on day 1) and group B (the same as group A plus LV 200 mg/m2/day by 2 h intravenous infusion with 5FU intravenous push at midinfusion). No significant difference in response rate was noticed between the two treatment arms; there were two (5%) patients with complete response in group A, and five (12%) in A and 11 (26%) partial responders in group B (p < 0.1). A significantly higher number of patients achieving stable disease was observed in group B; 19 (44%) in comparison to group A 10 (24%) (p < 0.048). There were more patients with progressive disease in group A 25 (59%) than in group B 12 (28%) (p < 0.003) (Table 2). No difference was noted in mean duration of response: group A, 15.8 (6-31) weeks; and group B, 17.6 (6-28) weeks. The mean time to progression was for group A [11.4 (6-35) weeks] and for group B [17.6 (8-33) weeks]. Mean survival was for group A [27.4 (12-59) weeks] and for group B [30.6 (17-53) weeks], for 50% of patients. Causes of death were, for group A, 40 patients from disease progression and two sudden deaths; for group B, causes of death were for 41 patients disease progression and two sudden deaths. There were two patients in group A and one in group B that were not evaluable because they abandoned therapy after the first cycle. Toxicity was increased in group B; anemia, nausea and vomiting, and alopecia (p < 0.055) were more severe in group B, but not statistically different when compared to group A. Neutropenia, thrombocytopenia, mucositis, and fatigue of any grade were significantly more common and severe in group B. Significant dose reductions due to toxicity were required more commonly in group B. We conclude that the response rate was increased in the schedule with the addition of LV, at the cost of increased toxicity and with no difference in survival. A randomized trial comparing FEM-LV with new generation regimens would determine whether the addition of LV qualifies FAM equally active with these.

Adult↗

PubMed1999

Does ligation of the hypogastric artery at the time of radical hysterectomy and lymphadenectomy decrease blood loss? Results of a prospective randomized trial.

A prospective, randomized study of patients undergoing radical hysterectomy for gynecologic malignancies was undertaken from 10/95 to 11/96 to determine if ligation of the hypogastric arteries at the time of radical hysterectomy decreases blood loss. Patients were randomized to either ligation of the hypogastric artery (Group 1) or no ligation (Group 2) prior to a standard Piver type III radical hysterectomy. Surgeries were performed by Board certified gynecologic oncologists with gynecologic oncology fellows and/or OB/GYN residents. Patients were analyzed for demographic characteristics and intraoperative and postoperative parameters. Statistical analysis was performed with independent samples t-test, Mann-Whitney rank sum test, Chi square and Fisher exact test. Twenty-one patients were randomized to group 1 and 22 to group 2. Groups were similar with respect to demographics and preoperative parameters except for age. There were no differences among the groups with respect to intraoperative and postoperative parameters. The mean estimated blood loss for group 1 was 600 ml and 550 ml for group 2 (P = NS). Hypogastric artery ligation (HAL) at the time of radical hysterectomy for gynecologic malignancy does not reduce blood loss.

Journal Article↗

PubMed2003

A simple method for analyzing data from a randomized trial with a missing binary outcome.

BACKGROUND: Many randomized trials involve missing binary outcomes. Although many previous adjustments for missing binary outcomes have been proposed, none of these makes explicit use of randomization to bound the bias when the data are not missing at random. METHODS: We propose a novel approach that uses the randomization distribution to compute the anticipated maximum bias when missing at random does not hold due to an unobserved binary covariate (implying that missingness depends on outcome and treatment group). The anticipated maximum bias equals the product of two factors: (a) the anticipated maximum bias if there were complete confounding of the unobserved covariate with treatment group among subjects with an observed outcome and (b) an upper bound factor that depends only on the fraction missing in each randomization group. If less than 15% of subjects are missing in each group, the upper bound factor is less than.18. RESULTS: We illustrated the methodology using data from the Polyp Prevention Trial. We anticipated a maximum bias under complete confounding of.25. With only 7% and 9% missing in each arm, the upper bound factor, after adjusting for age and sex, was.10. The anticipated maximum bias of.25 x.10 =.025 would not have affected the conclusion of no treatment effect. CONCLUSION: This approach is easy to implement and is particularly informative when less than 15% of subjects are missing in each arm.

Adenoma↗

PubMed2002

Lack of concealment may lead to selection bias in cluster randomized trials of palliative care.

Comprehensive palliative care programs are often implemented on a community level, and to evaluate such interventions, randomization by cluster (community) may be the only feasible method. In trials randomizing individual subjects, the importance of proper concealment has been stressed. In cluster randomized trials, however, concealment of individual patient allocation is often impossible. The following risk of selection bias has been given little attention. In the present study, comparing palliative care to conventional care, community health care districts were defined as clusters and randomized. The patients' treatment assignment was determined by the allocation of the cluster in which they resided, and hence predictable by their address. A biased selection based on practical considerations related to patients' diagnoses and hospital departments was suspected. To explore this, cancer diagnoses were grouped according to local tradition for sharing of treatment responsibility among hospital departments. A significant difference between trial arms in distribution of these groups was revealed and strongly supported our suspicion. The finding carries an important message to future researchers: when using cluster randomization, any evidence of selection bias should be carefully checked and reported.

Adult↗

PubMed1985

The demand for dental care: evidence from a randomized trial in health insurance.

Using data from a randomized trial in health insurance, this paper examines the effect of cost sharing on use of dental services. The data come from a sample of the nonaged, noninstitutionalized civilian population of six urban and rural sites. We find that: reducing the level of cost sharing increases demand for dental services; and dental expenses rise 46% when the coinsurance rate falls from 95% to 0%, subject to a catastrophic limit on out-of-pocket expenses. Of this increase, two-thirds is attributable to an increase in the likelihood of visiting a dentist during the year. Moreover, there is a substantial surge in demand during the first year of more generous coverage. The first-year response to cost sharing is nearly twice the second-year response.

Adolescent↗

PubMed2004

Pitfalls of and controversies in cluster randomization trials.

It is now well known that standard statistical procedures become invalidated when applied to cluster randomized trials in which the unit of inference is the individual. A resulting consequence is that researchers conducting such trials are faced with a multitude of design choices, including selection of the primary unit of inference, the degree to which clusters should be matched or stratified by prognostic factors at baseline, and decisions related to cluster subsampling. Moreover, application of ethical principles developed for individually randomized trials may also require modification. We discuss several topics related to these issues, with emphasis on the choices that must be made in the planning stages of a trial and on some potential pitfalls to be avoided.

Bias↗

PubMed1990

Recurrent superficial transitional cell carcinoma of the bladder: adjuvant topical chemotherapy versus immunotherapy. A prospective randomized trial.

A multicenter, prospective, randomized controlled study was begun in 1985 on the effect of ethoglucid and keyhole-limpet hemocyanin in the prevention of recurrent superficial transitional cell carcinoma of the bladder (stages pTa to pT1, grades 1 to 3 according to the recommendation of the International Union Against Cancer and the World Health Organization). The study was performed on a selected group of patients at high risk for further recurrences. All of these patients were pre-treated with different chemotherapeutic agents (doxorubicin or mitomycin C) and still had recurrent superficial transitional cell carcinoma. All tumors were removed by transurethral resection and all patients were presumed to be free of tumor at initiation of the prophylactic instillations. Patients in the ethoglucid group received 0.565 gm. (solution of 1%) ethoglucid weekly for 6 weeks and then monthly for 1 year. Patients in the keyhole-limpet hemocyanin group were immunized with 1 mg. keyhole-limpet hemocyanin intracutaneously, and then weekly bladder instillations of 30 mg. were given for 6 weeks and then monthly for 1 year. The percentage of recurrences, recurrence rate, interval free of disease, tumor progression and effect on downstaging were evaluated for both therapeutic arms. The percentage of recurrences (60.9% in the ethoglucid group versus 55.3% in the keyhole-limpet hemocyanin group) and the comparison of interval to recurrence for all patients showed no statistical significant difference (p = 0.808, Mantel-Cox test). A comparison of the interval to recurrence in patients with recurrent tumors only showed a mean interval free of disease of 8.8 months for patients given ethoglucid versus 5.5 months for those given keyhole-limpet hemocyanin (p = 0.006, Wilcoxon test). Recurrence rate (4.8 versus 6.5, respectively) and tumor progression rate (21.7 versus 21.1%, respectively) showed no statistically significant difference (p greater than 0.1).

Administration, Intravesical↗

PubMed2003

The verdict is not in yet. Analysis of the randomized trials of high-dose chemotherapy for breast cancer.

BACKGROUND: The relative efficacy of high-dose chemotherapy (HDC) compared to standard treatment for high-risk primary (HRPBC) or metastatic breast cancer (MBC) constitutes an area of intense controversy among the medical oncology community. A number of randomized trials have been conducted to address this issue. In most cases, the results of these trials are premature and contradictory. Furthermore, they have often been interpreted, incorrectly in this author's judgment, as proof of lack of benefit of HDC. EVIDENCE AND INFORMATION SOURCES: The results of studies published in peer-reviewed medical journals or presented in scientific meetings are discussed. In some cases, the status of the studies was determined through direct communication with the trial's principal investigator. RESULTS: The encouraging results of phase II trials suggested a benefit for HDC in important categories of patients with breast cancer. It has been argued that selection of patients might have been a critical factor in those studies. The results, in most cases preliminary, of numerous randomized trials in metastatic and high-risk primary disease cannot offer a definitive answer to this crucial question as of yet. Important concepts in the interpretation of these studies, such as size and statistical power, length of follow-up, magnitude of clinical benefit, and broad applicability of the results, are discussed in this review. CONCLUSIONS: The role of HDC for HRPBC or MBC patients remains undefined. Longer follow-up and mature analyses of the randomized trials are necessary before definitive conclusions are drawn. In the meantime, it is imperative that research continues, to enhance the efficacy of the procedure through innovative strategies.

Antineoplastic Agents↗