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Results for “randomized trial”

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At least 55 records · Page 3Linked to original sources
PubMed1997

The influence of risk on the results of warm heart surgery: a substudy of a randomized trial.

OBJECTIVE: The Warm Heart Investigators Trial randomized isolated coronary bypass patients to cold or warm cardioplegia, and demonstrated that warm cardioplegia significantly reduced the prevalence of low output syndrome and myocardial infarction (as defined by CKMB enzyme release). This study was designed prospectively as a subanalysis of the original trial, to determine the effect of warm heart surgery on high risk patients, who were anticipated to derive the major benefit from warm cardioplegia. METHODS: The prespecified endpoint for this study was a composite outcome of morbidity and mortality (death and/or low output syndrome and/or enzymatic myocardial infarction). Only patients with complete data for all outcomes were included, totalling 1374 patients (692 warm cardioplegia, 682 cold cardioplegia) who were randomized in the Warm Heart Investigators Trial. High medium and low risk patients were identified by a multivariate model of predicted risk for the study outcome. RESULTS: Analysis of the independent and interactive influence of cardioplegia technique and predicted risk demonstrated that warm cardioplegia significantly reduced the overall prevalence of morbidity and mortality (warm: 15.9 versus cold: 25.2%, P < 0.01). However, no significant differences in warm-cold effects were detected among risk terciles. Cardioplegia technique had a similar differential influence on mortality and morbidity in low risk patients (warm: 7.3, cold: 17.4%) as it did in high risk patients (warm: 31.1, cold: 39.9%). CONCLUSIONS: Although our analysis confirms the overall benefits of warm cardioplegia, our unanticipated finding in high risk subjects may be explained by the fact that morbidity and mortality in that patient subgroup is caused not only by poor myocardial protection, but by other clinical and technical factors. Further studies are necessary to identify those patients who might benefit most from improved myocardial protection techniques.

Adult↗
PubMed1999

Rationale and design of The National Emphysema Treatment Trial: a prospective randomized trial of lung volume reduction surgery. The National Emphysema Treatment Trial Research Group.

The National Emphysema Treatment Trial is a multicenter, randomized clinical trial of medical therapy vs medical therapy plus lung volume reduction surgery (LVRS) for the treatment of patients with severe bilateral emphysema. LVRS will be accomplished by bilateral stapled excision via median sternotomy or video-assisted thoracoscopic surgery. Every patient will complete 6 to 10 weeks of pulmonary rehabilitation prior to randomization and will participate in a maintenance program of pulmonary rehabilitation after randomization. The primary outcome to be assessed by the trial is survival. Additional outcomes to be assessed are maximum exercise capacity, pulmonary function, oxygen requirement, distance walked in 6 min, quality of life, respiratory symptoms, and health-care utilization and costs. In addition, selected clinics will evaluate lung mechanics and respiratory muscle function, partial and maximal flow-volume curves, gas exchange during maximal exercise, and right heart function. The trial is targeted to enroll patients with severe emphysema who have no significant comorbid conditions; each patient will be randomized to one of the two treatment groups. The study duration is 4.5 years with a close-out period of 6 months.

Humans↗
PubMed2000

Canadian National Breast Screening Study-2: 13-year results of a randomized trial in women aged 50-59 years.

BACKGROUND: Screening for breast cancer with mammography in women aged 50 years or more has been shown to reduce mortality from breast cancer. However, the extent to which mammography contributes to the reduction of mortality in women who also undergo physical examination of the breasts is not known. This study was designed to compare breast cancer mortality following annual screening consisting of two-view mammography and physical examination of the breasts with mortality following annual screening by physical examination only. Breast self-examination was taught to all participants. METHODS: This trial randomly and individually assigned 39 405 women aged 50-59 years, recruited from January 1980 through March 1985, to one of the study arms. The women were followed by record linkage with the Canadian National Cancer Registry and National Mortality Database to December 31, 1993, and by active follow-up of breast cancer patients to June 30, 1996. RESULTS: Randomization achieved virtually equal distribution of demographic and breast cancer risk variables. At the first annual screen, 21% of the cancers found by mammography alone (in the mammography plus physical examination group) were 20 mm or more in size compared with 46% of those found by physical examination in the mammography plus physical examination group and 56% in the physical examination-only group. The corresponding percentages for screens 2-5 were 10%, 42%, and 50%, respectively. Screening detected 267 invasive breast cancers in the mammography plus physical examination group compared with 148 in the physical examination-only group. By December 31, 1993, 622 invasive and 71 in situ breast carcinomas were ascertained in the mammography plus physical examination group, and 610 and 16 were ascertained in the physical examination-only group. At 13-year follow-up, with 107 and 105 deaths from breast cancer in the respective groups, the cumulative rate ratio was 1.02 (95% confidence interval = 0.78-1.33). CONCLUSION: In women aged 50-59 years, the addition of annual mammography screening to physical examination has no impact on breast cancer mortality.

Breast Neoplasms↗
PubMed2000

Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial.

PURPOSE: This trial was designed to identify factors affecting patency rates of primary prosthetic above-knee femoropopliteal bypass grafts at 5 years. METHODS: A multi-institutional, prospective trial randomized 240 patients to compare patency rates of Gore-tex and Hemashield above-knee femoropopliteal bypass grafts at 5 years. Univariate comparisons of patency between levels of each prognostic variable were made with the Kaplan-Meier method. Variables that had a univariate P value less than.25 or those known to be important were submitted to a Cox regression analysis. RESULTS: The patient survival rate at 5 years was 59.4%. There were no differences in primary or secondary patency rates at 5 years between the two graft materials (primary, 45% vs 43% and secondary, 68% vs 68%). The risk for graft occlusion was significantly increased for patients younger than 65 years (2.1; P =.001) and for grafts with a diameter less than 7 mm (1.65; P =.0219). Variables with no apparent independent effect on patency rates were smoking status, runoff, diabetes mellitus, sex, presenting symptoms, and postoperative treatment with aspirin or Coumadin. Noninvasive test results were not predictive of subsequent graft function. CONCLUSION: Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared.

Aged↗
PubMed2001

Rapid emergency department intervention for older people reduces risk of functional decline: results of a multicenter randomized trial.

OBJECTIVES: To determine the effectiveness of a two-stage (screening and nursing assessment) intervention for older patients in the emergency department (ED) who are at increased risk of functional decline and other adverse outcomes. DESIGN: Controlled trial, randomized by day of ED visit, with follow-up at 1 and 4 months. SETTING: Four university-affiliated hospitals in Montreal. PARTICIPANTS: Patients age 65 and older expected to be released from the ED to the community with a score of 2 or more on the Identification of Seniors At Risk (ISAR) screening tool and their primary family caregivers. One hundred seventy-eight were randomized to the intervention, 210 to usual care. INTERVENTION: The intervention consisted of disclosure of results of the ISAR screen, a brief standardized nursing assessment in the ED, notification of the primary care physician and home care providers, and other referrals as needed. The control group received usual care, without disclosure of the screening result. MEASUREMENTS: Patient outcomes assessed at 4 months after enrollment included functional decline (increased dependence on the Older American Resources and Services activities of daily living scale or death) and depressive symptoms (as assessed by the short Geriatric Depression Scale). Caregiver outcomes, also assessed at baseline and 4 months, included the physical and mental summary scales of the Medical Outcomes Study Short Form-36. Patient and caregiver satisfaction with care were assessed 1 month after enrollment. RESULTS: The intervention increased the rate of referral to the primary care physician and to home care services. The intervention was associated with a significantly reduced rate of functional decline at 4 months, in both unadjusted (odds ratio (OR) = 0.60, 95% confidence interval (CI) = 0.36-0.99) and adjusted (OR = 0.53, 95% CI = 0.31-0.91) analyses. There was no intervention effect on patient depressive symptoms, caregiver outcomes, or satisfaction with care. CONCLUSION: A two-stage ED intervention, consisting of screening with the ISAR tool followed by a brief, standardized nursing assessment and referral to primary and home care services, significantly reduced the rate of subsequent functional decline.

Activities of Daily Living↗
PubMed2006

Should chemotherapy combinations for advanced non-small cell lung cancer be platinum-based? A meta-analysis of phase III randomized trials.

BACKGROUND: Non-platinum regimens have been proposed as an alternative to the platinum-based combinations for treatment of advanced non-small cell lung cancer. However, conflicting results were reported. METHODS: Meta-analysis of phase III trials randomizing platinum-based versus non-platinum combinations as first-line chemotherapy with 1-year survival rate as a primary endpoint. Fourteen trials have been identified. Experimental arms were gemcitabine/vinorelbine (n=4), gemcitabine/taxane (n=7), gemcitabine/epirubicin (n=1), paclitaxel/vinorelbine (n=1), and gemcitabine/ifosfamide (n=1). The comparator was a doublet of a platinum compound plus a third generation agent for all but two studies (triplets). Updated data were available for 13 studies. The Peto and Yusuf method was used to generate odds ratios (OR). All tests are two-sided. RESULTS: A statistical heterogeneity was detected when the 13 studies were analyzed. Considering that current guidelines recommend platinum-based doublets as standard therapy we therefore limited the meta-analysis to the set of 11 phase III studies which used a platinum-based doublet (2298 and 2304 patients in platinum-based and non-platinum arms, respectively). No significant heterogeneity was detected in this consistent group of studies. Patients treated with a platinum-based regimen benefited from a statically significant reduction in the risk of death at 1 year (OR: 0.88, 95% CI 0.78-0.99; p=0.044) and a lower risk of being refractory to chemotherapy (OR: 0.87, 0.73-0.99; p=0.049). Forty-four (1.9%) and 29 (1.3%) toxic-related deaths were reported for platinum-based and non-platinum regimens, respectively (OR: 1.53; 0.96-2.49, p=0.08). An increased risk of grade 3-4 gastro-intestinal and hematological toxicity for patients receiving platinum-based chemotherapy was statistically demonstrated. There was no statically significant increase in risk of febrile neutropenia, OR=1.23 (0.94-1.60, p=0.063). CONCLUSION: A platinum-based doublet induced a statically significant reduction in the risk of death when compared with non-platinum chemotherapy without inducing an unacceptable increase in toxicity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Randomized trial of rate-control versus rhythm-control in persistent atrial fibrillation: the Strategies of Treatment of Atrial Fibrillation (STAF) study.

OBJECTIVES: This study was designed to compare two treatment strategies in patients with atrial fibrillation(AF): rhythm-control (restoration and maintenance of sinus rhythm) and rate-control (pharmacologic or invasive rate-control and anticoagulation). BACKGROUND: Atrial fibrillation is the most common arrhythmia. It is unclear whether a strategy of rhythm- or rate-control is better in terms of mortality, morbidity, and quality of life. METHODS: The Strategies of Treatment of Atrial Fibrillation (STAF) multicenter pilot trial randomized 200 patients (100 per group) with persistent AF to rhythm- or rate-control. The combined primary end point was a combination of death, cardiopulmonary resuscitation, cerebrovascular event, and systemic embolism. RESULTS: After 19.6 +/- 8.9 months (range 0 to 36 months) there was no difference in the primary end point between rhythm-control (9/100; 5.54%/year) and rate-control (10/100; 6.09%/year; p = 0.99). The percentage of patients in sinus rhythm in the rhythm-control group after up to four cardioversions during the follow-up period (rate-control group) was 23% (0%) at 36 months. Eighteen primary end points occurred in atrial fibrillation; only one occurred in sinus rhythm (p = 0.049). CONCLUSIONS: The STAF pilot study showed no differences between the two treatment strategies in all end points except hospitalizations. These data suggest that there was no benefit in attempting rhythm-control in these patients with a high risk of arrhythmia recurrence. It remains unclear whether the results in the rhythm-control group would have been better if sinus rhythm had been maintained in a higher proportion of patients, as all but one end point occurred during AF.

Adult↗
PubMed2004

Sample size calculator for cluster randomized trials.

Cluster randomized trials, where individuals are randomized in groups are increasingly being used in healthcare evaluation. The adoption of a clustered design has implications for design, conduct and analysis of studies. In particular, standard sample sizes have to be inflated for cluster designs, as outcomes for individuals within clusters may be correlated; inflation can be achieved either by increasing the cluster size or by increasing the number of clusters in the study. A sample size calculator is presented for calculating appropriate sample sizes for cluster trials, whilst allowing the implications of both methods of inflation to be considered.

Algorithms↗
PubMed2005

An estimator for treatment comparisons among survivors in randomized trials.

In clinical trials of advanced-stage disease it is often of interest to perform treatment comparisons for endpoints which are defined only for survivors. Examples include time on ventilation in ventilation studies, change in quality of life in health-related quality-of-life studies, and duration of response to therapy in therapeutic trials. Randomized treatment comparisons for these endpoints cannot be performed because the outcomes are only defined in the nonrandomly selected subgroup of survivors. We propose a new evaluation of the survivor average causal effect (SACE) for treatment comparisons of this nature. We provide an estimator of SACE in the presence of no unmeasured confounders, a nontestable assumption, which identifies SACE. We also outline a sensitivity analysis for exploring robustness of conclusions to deviations from this assumption. We apply this method to duration of ventilation in a clinical trial of acute respiratory distress syndrome.

Biometry↗
PubMed2026

Adjunctive middle meningeal artery embolization for chronic subdural hematoma: A systematic review and meta-analysis of eight randomized trials.

BACKGROUND: Randomized trials suggest that adjunctive middle meningeal artery embolization (MMAE) may reduce recurrence in chronic subdural hematoma (CSDH), but potential sources of variability in treatment effects across studies remain poorly understood. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of MMAE and to explore potential study-level sources of between-study heterogeneity. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials comparing MMAE plus surgery versus surgery alone, following PRISMA guidelines. Trial sequential analysis (TSA) was prespecified to assess the robustness of pooled findings. Exploratory mixed-effects meta-regression was performed to examine whether aggregate study-level mean age and anticoagulation use were associated with variability in recurrence outcomes. RESULTS: Eight trials including 1961 patients were analyzed. MMAE plus surgery was associated with a reduction in recurrence compared with surgery alone (RR 0.63, 95% CI 0.46-0.85; I&#xb2; = 0%), and TSA supported this finding. Although conventional meta-analysis suggested a reduction in reoperation, the TSA findings were more sensitive to analytical assumptions and less robust. Exploratory study-level meta-regression analyses suggested possible associations between recurrence outcomes and mean age or anticoagulation use, although these findings should be interpreted as hypothesis-generating only. Safety outcomes were comparable between groups. CONCLUSIONS: Adjunctive MMAE was associated with reduced recurrence in CSDH. Exploratory analyses evaluating aggregate study-level characteristics were limited by the small number of included trials and the use of aggregate-level data, and should be considered hypothesis-generating only. Further prospective studies are needed to better understand variability in treatment effects.

Humans↗
PubMed2000

Rationale and design of the national emphysema treatment trial. A prospective randomized trial of lung volume reduction surgery. The national emphysema treatment trial research group

The National Emphysema Treatment Trial is a multicenter, randomized clinical trial of medical therapy vs medical therapy plus lung volume reduction surgery (LVRS) for the treatment of patients with severe bilateral emphysema. LVRS will be accomplished by bilateral stapled excision via median sternotomy or video-assisted thoracoscopic surgery. Every patient will complete 6 to 10 weeks of pulmonary rehabilitation prior to randomization and will participate in a maintenance program of pulmonary rehabilitation after randomization. The primary outcome to be assessed by the trial is survival. Additional outcomes to be assessed are maximum exercise capacity, pulmonary function, oxygen requirement, distance walked in 6 min, quality of life, respiratory symptoms, and health-care utilization and costs. In addition, selected clinics will evaluate lung mechanics and respiratory muscle function, partial and maximal flow-volume curves, gas exchange during maximal exercise, and right heart function. The trial is targeted to enroll patients with severe emphysema who have no significant comorbid conditions; each patient will be randomized to one of the two treatment groups. The study duration is 4.5 years with a close-out period of 6 months.

Journal Article↗
PubMed2005

Effects of calcium, dairy product, and vitamin D supplementation on bone mass accrual and body composition in 10-12-y-old girls: a 2-y randomized trial.

BACKGROUND: Little is known about the relative effectiveness of calcium supplementation from food or pills with or without vitamin D supplementation for bone mass accrual during the rapid growth period. OBJECTIVE: The purpose was to examine the effects of both food-based and pill supplements of calcium and vitamin D on bone mass and body composition in girls aged 10-12 y. DESIGN: This placebo-controlled intervention trial randomly assigned 195 healthy girls at Tanner stage I-II, aged 10-12 y, with dietary calcium intakes <900 mg/d to 1 of 4 groups: calcium (1000 mg) + vitamin D3 (200 IU), calcium (1000 mg), cheese (1000 mg calcium), and placebo. Primary outcomes were bone indexes of the hip, spine, and whole body by dual-energy X-ray absorptiometry and of the radius and tibia by peripheral quantitative computed tomography. RESULTS: With the use of intention-to-treat or efficacy analysis, calcium supplementation with cheese resulted in a higher percentage change in cortical thickness of the tibia than did placebo, calcium, or calcium + vitamin D treatment (P = 0.01, 0.038, and 0.004, respectively) and in higher whole-body bone mineral density than did placebo treatment (P = 0.044) when compliance was >50%. With the use of a hierarchical linear model with random effects to control for growth velocity, these differences disappeared. CONCLUSIONS: Increasing calcium intake by consuming cheese appears to be more beneficial for cortical bone mass accrual than the consumption of tablets containing a similar amount of calcium. Diverse patterns of growth velocity may mask the efficacy of supplementation in a short-term trial of children transiting through puberty.

Absorptiometry, Photon↗
PubMed1994

Home visitation services for at-risk pregnant and postpartum women: a randomized trial.

A randomized trial tested the psychosocial efficacy of a home visitation model for women at risk of out-of-home placement of their newborns. After an average of ten months of exposure, the experimental group reported significantly increased social support, greater access to services, and decreased psychological distress. Implications of the findings for interventions with at-risk families are discussed.

Adolescent↗
PubMed1994

Preventing falls among community-dwelling older persons: results from a randomized trial.

A randomized trial of falls prevention program that addressed home safety, exercise, and behavioral risks was conducted with 3,182 independently living HMO members age 65 and older. The intervention decreased the odds of falling by 0.85, but only reduced the average number of falls among those who fell by 7%. The effect was strongest among men age 75 and older. The likelihood of avoiding falls requiring medical treatment was not significantly affected by the intervention. We conclude that the intervention dose was not of sufficient intensity or duration to have a marked protective effect on older persons. Future research should focus on more intensive intervention approaches because serious falls do not appear to be amendable to low-intensity environment/behavioral efforts.

Accidental Falls↗
PubMed1990

Combination therapy with bestatin in inoperable lung cancer. A randomized trial.

A randomized trial of combination therapy with bestatin (30 mg daily, every day) was performed in 238 patients with inoperable primary lung cancer from August, 1981 through April, 1984. Of the 238 patients, 227 were evaluable: 113 treated by bestatin combination therapy and 114 controls. There was no statistically significant difference in response rate or survival between the 2 groups. In squamous cell cancer response was observed in 34.5% of the bestatin group and 17.9% of the control group. The analysis, including Cox's proportional hazard model, revealed that the survival tended to be longer in the bestatin group (median survival 40 weeks) than in the control group (median survival 24 weeks; p = 0.051). This suggests that addition of bestatin might be beneficial in squamous cell cancer of the lung but further, more rigidly controlled, clinical trials are necessary before more definitive conclusions can be drawn.

Aged↗
PubMed1989

Adjuvant chemotherapy (CMF) for stage III breast cancer: a randomized trial.

A randomized trial of the effect of adjuvant CMF chemotherapy in patients with Stage III breast cancer receiving primary local radiation or local radiation plus surgery, failed to reveal a survival benefit from early systemic treatment. The subset of premenopausal patients receiving chemotherapy did, however, show a significant prolongation of disease-free survival from 23 to 55 months. Overall survival of this subgroup was not increased. The study included the use of two dose levels of CMF to assess whether higher chemotherapy doses would be more effective. No dose effect was observed. Initial local control with radiation therapy or radiation plus surgery was achieved in the majority (90.9%). Distal recurrence and death from metastatic disease were the major causes of treatment failure. Treatment benefit among premenopausal patients was mainly delayed onset of distal metastatic disease. Among premenopausal patients, salvage therapy for metastatic disease appeared more effective in those not previously exposed to systemic treatment.

Adult↗
PubMed1980

Prognostic effect of early diagnostic splenectomy in Hodgkin's disease: a randomized trial.

A randomized trial is reported which evaluates the effect of early diagnostic splenectomy on the prognosis of patients with Hodgkin's disease (HD) and uncertain prognosis. This was started in January 1973 and concluded in April 1979. Sixty-seven patients were entered in the study and 31 were randomized for splenectomy. All patients except 2 received total nodal irradiation, excluding the splenic and hepatic areas. After 40 months' observation there was no difference between the groups in respect of survival and the number of recurrences. However, relapses occurred earlier in the splenectomized patients. Pneumococcal septicaemia was recorded in 2 splenectomized patients. It is concluded that prognosis is not improved by diagnostic splenectomy in HD patients with uncertain prognosis and treated with total nodal irradiation.

Adolescent↗