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PubMed1989

Treatment in the Hypertension Prevention Trial. Hypertension Prevention Trial Research Group.

The Hypertension Prevention Trial (HPT) was a randomized, controlled, multicenter (four clinics, four resource centers) trial designed to test the feasibility of achieving and sustaining dietary changes in the intake of calories, sodium, and potassium and to assess the effect of those changes on blood pressure in a normotensive population. The trial involved 841 men and women (plus a test cohort of 78) who, at the first baseline (BL) examination were in the age range of 25-49 years and had diastolic blood pressure (DBP) greater than or equal to 76 but less than 100 mm Hg (average of two readings), and at the examination prior to randomization (BL 2) had DBP greater than or equal to 78 but less than 90 mm Hg (also averaged). Participants were randomly assigned to a control treatment group (no dietary counseling) or to one of four dietary treatment groups involving counseling designed to reduce calorie intake, reduce sodium intake, reduce sodium and calorie intake, and reduce sodium and increase potassium intake. This chapter describes the counseling methods employed to help participants achieve the desired dietary changes. Counseling was provided to groups by trained interventionists and included instruction in food selection, food preparation, and behavior management skills. Counseling groups met weekly for the first 10 weeks of the trial, twice the following month, and bimonthly thereafter. Techniques used in the counseling program included group discussions, instructions for dietary record keeping, goal setting, individual diet analysis for each participant, cooking demonstrations, and taste testing of new foods.

Adult↗
PubMed1992

Enrollment in clinical trials: institutional factors affecting enrollment in the cardiac arrhythmia suppression trial (CAST).

Recruitment and Enrollment Assessment in Clinical Trials (REACT), an NHLBI-sponsored substudy of the Cardiac Arrhythmia Suppression Trial (CAST), was conducted to assess factors associated with enrollment in clinical trials. We report on the relationships of institutional factors at CAST sites to patient enrollment. The proportion of CAST-eligible patients enrolling at each CAST site during the REACT study period was defined as the number of subjects enrolled divided by the sum of (1) the number enrolled plus (2) the number of eligibles who refused plus (3) the number of eligibles whose physicians refused to permit CAST personnel to attempt to enroll them. A questionnaire that included 78 questions regarding factors hypothesized to be associated with enrollment was completed between August 1988 and February 1990 by the nurse coordinators at all 112 CAST sites in the United States and Canada. Sixteen items were unanalyzable, and 37 of the remaining 62 were grouped into seven scales. The remaining items were analyzed individually. Enrollment proportions varied widely across the 112 CAST sites (mean 32.7% SD 22.6). Five variables or scales were included in the final multiple regression model (multiple R2 = .39). The most important of these was the proportion of eligible patients at a site cared for by medical staff other than private attending physicians (multiple R2 for this variable alone, .26). This proportion tended to be high in teaching hospitals. Other variables in this model that were associated with higher enrollment proportions included the number of days per week a nurse coordinator was present at the site, the number of nurse coordinator full-time equivalents at the site, fewer other clinical trials for which the nurse coordinator was responsible, and fewer perceived obstacles to enrollment. These findings indicate that enrollment was more successful at hospitals with higher proportions of eligible subjects cared for by fellows, housestaff, and service attending physicians and at institutions with the committed presence of a nurse-coordinator.

Arrhythmias, Cardiac↗
PubMed1993

Design features of a controlled clinical trial to assess the effect of an HMG CoA reductase inhibitor on the progression of coronary artery disease. Canadian Coronary Atherosclerosis Intervention Trial Investigators Montreal, Ottawa, and Toronto, Canada.

This report describes the design and methodological features of a double-masked, randomized, placebo-controlled trial to determine whether administration of the HMG CoA reductase inhibitor lovastatin retards the progression or facilitates the regression of coronary atherosclerosis. The study population consists of coronary patients with a recent arteriogram that characterizes them as being at high risk for coronary progression and a baseline fasting total serum cholesterol > or = 5.7 mmol/L and < or = 7.8 mmol/L. Lovastatin, or matching placebo, are up-titrated from 20 mg to 40 mg to 80 mg/day during the first 16 weeks of the study in an attempt to attain a fasting serum LDL cholesterol level of 3.4 mmol/L; patients and study personnel remain masked as to cholesterol levels throughout the trial. Coronary arteriography is repeated at 2 years, or earlier if necessitated by worsening symptoms, and all segments are measured quantitatively using a computer-based system. The primary outcome of the trial is a comparison between the lovastatin and placebo groups for coronary change score, defined as the mean of the minimum lumen diameter changes for all lesions (follow-up minus baseline arteriogram) per patient. The advantages and limitations of coronary arteriographic trials and some of the issues related to outcome measurements are discussed. The question posed by this study is of clinical relevance because the consequences of progression of coronary disease, angina, myocardial infarction, and sudden cardiac death are leading causes of morbidity and mortality.

Adult↗
PubMed1996

Rationale, design, implementation, and baseline characteristics of patients in the DIG trial: a large, simple, long-term trial to evaluate the effect of digitalis on mortality in heart failure.

This article provides a detailed overview of the rationale for key aspects of the protocol of the Digitalis Investigation Group (DIG) trial. It also highlights unusual aspects of the study implementation and the baseline characteristics. The DIG trial is a large, simple, international placebo-controlled trial whose primary objective is to determine the effect of digoxin on all cause mortality in patients with clinical heart failure who are in sinus rhythm and whose ejection fraction is < or = 0.45. An ancillary study examines the effect in those with an ejection fraction > 0.45. Key aspects of the trial include the simplicity of the design, broad eligibility criteria, essential data collection, and inclusion of various types of centers. A total of 302 centers in the United States and Canada enrolled 7788 patients between February 1991 and September 1993. Follow-up continued until December 1995 with the results available in Spring 1996.

Aged↗
PubMed2004

Rationale, design, and baseline characteristics of 2 large, simple, randomized trials evaluating telmisartan, ramipril, and their combination in high-risk patients: the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial/Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease (ONTARGET/TRANSCEND) trials.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors reduce mortality, myocardial infarction, stroke, heart failure, need for revascularization, nephropathy, and diabetes and its complications. Although angiotensin-II receptor blockers (ARBs) have been less extensively evaluated, theoretically they may have "protective" effects similar to those of ACE inhibitors, but with better tolerability. Currently, there is uncertainty about the role of ARBs when used alone or in combination with an ACE inhibitor in high-risk populations with controlled hypertension. OBJECTIVES: Primary objectives of the ONgoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) are to determine if the combination of the ARB telmisartan and the ACE inhibitor ramipril is more effective than ramipril alone, and if telmisartan is at least as effective as ramipril. The Telmisartan Randomized AssessmeNt Study in aCE iNtolerant subjects with cardiovascular Disease (TRANSCEND) will determine if telmisartan is superior to placebo in patients who are intolerant of ACE inhibitors. The primary outcome for both trials is the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure. METHOD: High-risk patients with coronary, peripheral, or cerebrovascular disease or diabetes with end-organ damage are being recruited and followed for 3.5 to 5.5 years in 2 parallel, randomized, double-blind clinical trials. PROGRESS: Recruitment from 730 centers in 40 countries for ONTARGET (n = 25,620) was completed in July 2003. For TRANSCEND, 5776 patients (out of a projected total of 6000) have been recruited (by May 10, 2004). Baseline patient characteristics are comparable to the Heart Outcomes Prevention Evaluation (HOPE) trial, the basis of the design of the current study, confirming that patients are at high-risk.

Aged↗
PubMed2005

A randomised phase II trial of weekly high-dose 5-fluorouracil with and without folinic acid and cisplatin in patients with advanced biliary tract carcinoma: results of the 40955 EORTC trial.

UNLABELLED: Previous small phase II trials have demonstrated that the combination of 5-fluorouracil (5FU) and cisplatin(CDDP) could have clinical activity in metastatic biliary tract cancer. This randomised phase II trial was designed to assess the activity and safety of a high-dose infusional weekly 5FU alone (HDFU) and the combination of 5FU, folinic acid (FA) and CDDP. Patients were included if they had histologically proven locally advanced or metastatic biliary tract carcinoma, World Health Organisation (WHO) performance status < or = 2, bilirubin <2 x upper normal limit, adequate haematological and renal functions and had not received prior chemotherapy, even in the adjuvant setting. TREATMENTS: Arm A (HDFU) consisted of cycles of 5FU 3 g/m(2) intravenously (i.v.), 24 h infusion, weekly, for 6 weeks, followed by 1 week rest, every 7 weeks; Arm B (5FU+FA+CDDP) consisted of cycles of 5FU 2.0 g/m(2) i.v. with folinic acid 500 mg/m(2), 2 h-infusion, weekly, for 6 weeks, followed by 1 week rest plus cisplatin 50 mg/m(2), once every two weeks, for 6 weeks, followed by 1 week rest, every 7 weeks. From February 1997 to June 1999, 58 patients were randomised (29 in each arm). Patients had a median age of 58 years in Arm A and 62 years in Arm B, locally advanced disease was present in 21% of the patients in Arm A and 11% in Arm B. WHO performance status of 0/1/2 was noted in 48%/45%/7% of the patients in Arm A and 54%/43%/4% in Arm B. In both arms, the most common metastatic sites were the liver and peritoneum. Twenty-eight patients were eligible in each arm and one patient did not start the allocated therapy in Arm B. The median number of cycles was 2 [range 1-12] in Arm A and 2 [range 1-6] in Arm B. Responses for the eligible patients who started their allocated therapy were as follows: Complete Response (CR) 0% in Arm A, 4% in Arm B, Partial Response (PR) 7% in Arm A, 15% in Arm B resulting in an overall response rate [95% CI] of 7.1% in Arm A [0.9-23.5%] and 19% [6.3-38.1%] in Arm B. Disease stabilisation was observed in 46% in Arm A and 44% in Arm B. National Cancer Institute of Canada (NCIC) grade 3-4 adverse events (% of patients in Arm A/Arm B) were neutropenia 4%/26%, thrombopenia 0%/7%, stomatitis 0%/4%, vomiting 7%/14%, diarrhoea 0%/11% and neurotoxicity 4%/0%. There was one early toxic death in Arm B. The median overall survival (OS) [95% CI] was in Arm A/Arm B: 5.0 [4.0-7.4] months/8.0 [5.8-11.8] months and the median progression-free survival (PFS) was 3.3 [1.7-4.7] months/3.3 [2.3-6.7] months. Cisplatin in combination with 5FU+FA showed a higher activity than HDFU, but was more toxic. These results are not sufficient to start a phase III trial. However, our group is planning a phase III trial comparing 5FU+folinic acid versus the same schedule+oxaliplatin a platinum analogue.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

European Nicotinamide Diabetes Intervention Trial (ENDIT): a randomised controlled trial of intervention before the onset of type 1 diabetes.

BACKGROUND: Results of studies in animals and human beings suggest that type 1 diabetes is preventable. Nicotinamide prevents autoimmune diabetes in animal models, possibly through inhibition of the DNA repair enzyme poly-ADP-ribose polymerase and prevention of beta-cell NAD depletion. We aimed to assess whether high dose nicotinamide prevents or delays clinical onset of diabetes in people with a first-degree family history of type 1 diabetes. METHOD: We did a randomised double-blind placebo-controlled trial of nicotinamide in 552 relatives with confirmed islet cell antibody (ICA) levels of 20 Juvenile Diabetes Federation (JDF) units or more, and a non-diabetic oral glucose tolerance test. Participants were recruited from 18 European countries, Canada, and the USA, and were randomly allocated oral modified release nicotinamide (1.2 g/m2) or placebo for 5 years. Random allocation was done with a pseudorandom number generator and we used size balanced blocks of four and stratified by age and national group. Primary outcome was development of diabetes, as defined by WHO criteria. Analysis was done on an intention-to-treat basis. FINDINGS: There was no difference in the development of diabetes between the treatment groups. Of 159 participants who developed diabetes in the course of the trial, 82 were taking nicotinamide and 77 were on placebo. The unadjusted hazard ratio for development of diabetes was 1.07 (95% CI 0.78-1.45; p=0.69), and the hazard ratio adjusted for age-at-entry, baseline glucose tolerance, and number of islet autoantibodies detected was 1.01 (0.73-1.38; p=0.97). Of 168 (30.4%) participants who withdrew from the trial, 83 were on placebo. The number of serious adverse events did not differ between treatment groups. Nicotinamide treatment did not affect growth in children or first-phase insulin secretion. INTERPRETATION: Large-scale controlled trials of interventions designed to prevent the onset of type 1 diabetes are feasible, but nicotinamide was ineffective at the dose we used.

Autoimmune Diseases↗
PubMedDate not supplied

Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): multicentre, randomised controlled trial.

BACKGROUND: Laparoscopic-assisted surgery for colorectal cancer has been widely adopted without data from large-scale randomised trials to support its use. We compared short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer to predict long-term outcomes. METHODS: Between July, 1996, and July, 2002, we undertook a multicentre, randomised clinical trial in 794 patients with colorectal cancer from 27 UK centres. Patients were allocated to receive laparoscopic-assisted (n=526) or open surgery (n=268). Primary short-term endpoints were positivity rates of circumferential and longitudinal resection margins, proportion of Dukes' C2 tumours, and in-hospital mortality. Analysis was by intention to treat. This trial has been assigned the International Standard Randomised Controlled Trial Number ISRCTN74883561. FINDINGS: Six patients (two [open], four [laparoscopic]) had no surgery, and 23 had missing surgical data (nine, 14). 253 and 484 patients actually received open and laparoscopic-assisted treatment, respectively. 143 (29%) patients underwent conversion from laparoscopic to open surgery. Proportion of Dukes' C2 tumours did not differ between treatments (18 [7%] patients, open vs 34 [6%], laparoscopic; difference -0.3%, 95% CI -3.9 to 3.4%, p=0.89), and neither did in-hospital mortality (13 [5%] vs 21 [4%]; -0.9%, -3.9 to 2.2%, p=0.57). Apart from patients undergoing laparoscopic anterior resection for rectal cancer, rates of positive resection margins were similar between treatment groups. Patients with converted treatment had raised complication rates. INTERPRETATION: Laparoscopic-assisted surgery for cancer of the colon is as effective as open surgery in the short term and is likely to produce similar long-term outcomes. However, impaired short-term outcomes after laparoscopic-assisted anterior resection for cancer of the rectum do not yet justify its routine use.

Aged↗
PubMed2001

ACTG (AIDS Clinical Trials Group) 384: a strategy trial comparing consecutive treatments for HIV-1.

ACTG (AIDS Clinical Trials Group) 384 is designed to evaluate different strategies for antiretroviral treatment in HIV-1-infected individuals with no previous exposure to antiretroviral treatment. The study is a randomized, partially double-blinded, controlled trial with 980 subjects at 81 centers in the United States and Italy. The study has a factorial design that addresses the following scientific questions: (1) Does the best initial choice of therapy include both a protease inhibitor (PI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) in a four-drug combination with nucleoside analogue (NRTI) drugs, or should these agents be used sequentially in three-drug combinations?; (2) Which sequence is best in a three-drug regimen-PI followed by NNRTI or NNRTI followed by PI ?; (3) Which is the best sequence of dual NRTI combinations-zidovudine plus lamivudine followed by didanosine plus stavudine, or the converse? Subjects in the three-drug combination arms are offered a salvage regimen after failure of their second regimen; subjects in the four-drug combination arm are offered a salvage regimen after failure of their first regimen. The primary endpoint of the study is the time until salvage; secondary endpoints include time to virological failure and time to toxicity-related discontinuation of therapy. A Division of AIDS Data and Safety Monitoring Board will review the trial for safety and efficacy. Control Clin Trials 2001;22:142-159

Adolescent↗
PubMed1998

Intention-to-treat vs. on-treatment analyses of clinical trial data: experience from a study of pyrimethamine in the primary prophylaxis of toxoplasmosis in HIV-infected patients. ANRS 005/ACTG 154 Trial Group.

Randomized clinical trials analyzed by the intent-to-treat approach provide unbiased comparisons among treatment groups. To avoid dilution of treatment effect, many people also perform an analysis by treatment actually received, although this method may introduce bias into the results. This paper presents several approaches used for analyzing data of a recent trial and the difficulties encountered in interpreting the results of each approach. The ANRS 005/ACTG 154 Study was a double-blind, placebo-controlled, randomized, international (French, U.S., and Spanish) multicenter trial designed to assess the effectiveness of pyrimethamine for the primary prophylaxis of cerebral toxoplasmosis (CT) in HIV-infected patients with advanced immunodeficiency. In the intention-to-treat analysis, the cumulative probability of CT at 1 year did not differ significantly between the pyrimethamine arm (11.9%) and the placebo arm (13.1%), Hazard Ratio (HR) = 0.94 (95% Confidence Interval (CI) = 0.62-1.42), whereas an on-treatment analysis resulted in a significant difference: 4.2% in the pyrimethamine arm and 12.4% in the placebo arm, HR = 0.44 (95% CI = 0.24-0.80). The data showed a significant interaction between compliance and treatment outcome; and side effects were more frequently cited as reasons for compliance violations in the pyrimethamine group. Several different analytic approaches (censoring data at the time patients discontinued the study medication only for selected reasons) failed to explain the disparity between the estimation of effect of pyrimethamine by the intention-to-treat and on-treatment analyses. This experience led us to believe that comparing the results of both analyses was the best method to convince clinicians that intention-to-treat was the only interpretable analysis. We were concerned that even if pyrimethamine had a beneficial effect, it was very difficult (1) to quantify and (2) to apply to clinical practice unless one could predict the occurrence of study drug discontinuation for each patient at the time of treatment assignment. Although exploratory analyses may yield clinically relevant information and useful clarifications in the evaluation of treatments, intention-to-treat remains the only interpretable analysis of clinical trials.

AIDS-Related Opportunistic Infections↗
PubMed1998

CD4 cell count as a surrogate endpoint in HIV clinical trials: a meta-analysis of studies of the AIDS Clinical Trials Group.

OBJECTIVE: To evaluate initial changes in CD4 cell count as a surrogate endpoint for clinical outcome in HIV-infected patients. DESIGN: Meta-analysis of all relevant Phase II and III randomized clinical trials undertaken by the Adult AIDS Clinical Trials Group. METHODS: Individual patient data were obtained from each clinical trial, and the difference between a pair of treatments in their effect on clinical outcome (AIDS or death, or death alone) during 2 years of follow-up was evaluated. The proportion of treatment effect explained (PTE) was the proportion of this difference explained by the change in CD4 cell count 6 months after starting treatment, evaluated using proportional hazards models. A weighted average PTE across treatment comparisons was obtained. The association between the difference between treatments in clinical outcome, expressed as hazard ratio, and the difference in mean change in CD4 cell count was evaluated using regression analysis. RESULTS: There were 15 clinical trials involving 24 treatment comparisons. The weighted average PTE for both progression to AIDS or death was 0.16 [95% confidence interval (Cl), 0.07-0.26] and for death was 0.10 (95% Cl, 0.00-0.20). There were significant associations between treatment differences in effect on AIDS or death, and on death alone, and the difference in mean change in CD4 cell count. A difference in mean change in CD4 cell count of 30 or 40 x 10(6)/l or more in favor of the test treatment indicated with high probability that there was a corresponding difference in progression to AIDS or death. CONCLUSIONS: The small PTE suggest that other mechanisms of drug action not captured by initial change in CD4 cells are important. CD4 cell count is a weak surrogate endpoint, but has some value as an aid for screening treatments for drug development or preliminary regulatory approval.

Anti-HIV Agents↗
PubMed2000

Inclusion of older women in randomized clinical trials: factors associated with taking study medication in the fracture intervention trial.

OBJECTIVES: The purpose of this study is to describe the early study medication discontinuation (SMD) experience during the first year of follow-up in a randomized clinical trial in older women and to determine the associations between various baseline characteristics and risk of SMD. DESIGH, SETTING, AND PARTICIPANTS: The authors studied 6,459 postmenopausal women aged 55 to 80 from 11 clinical settings during their first year of participation in the Fracture Intervention Trial (FIT). This trial was designed to test the efficacy of alendronate (Fosamax) on fracture prevention among women with low bone mass. RESULTS: Study medication discontinuation was greatest in the first month post-randomization (2.2%) and declined thereafter. Cumulative rates of study medication discontinuation were 4.8% (n = 311) at 3 months and 11.1% (n = 717) at 12 months. SMD was not associated with age, marital status, alcohol consumption, regular exercise, past estrogen replacement therapy use, bone mineral density, or personal or maternal fracture history. After adjusting for covariates and markers of comorbidity, the strongest predictor of SMD was fair-to-poor self-rated health (relative risk (RR) 2.10; 95% confidence interval (CI) 1.47, 2.99). Having four or more depressive symptoms was also a significant predictor and had a risk associated with SMD (RR vs none 1.34; 95% CI 1.05, 1.71) similar to that seen for individuals with good self-rated health (RR 1.49; 95% CI 1.16, 1.91). CONCLUSIONS: Results from this cohort emphasize that clinical trials in older women with multiple concomitant conditions can achieve high levels of adherence. Thought should be given to measuring self-rated health and depressive symptoms before randomization to help identify individuals to be targeted for special assistance programs that focus on encouraging adherence.

Aged↗
PubMed1978

Evaluation of drug treatment in mild hypertension: VA-NHLBI feasibility trial. Plan and preliminary results of a two-year feasibility trial for a multicenter intervention study to evaluate the benefits versus the disadvantages of treating mild hypertension. Prepared for the Veterans Administration-National Heart, Lung, and Blood Institute Study Group for Evaluating Treatment in Mild Hypertension.

A feasibility trial to investigate the practicality of determining the advantages and disadvantages of prompt pharmacologic treatment for mild hypertension was jointly funded by the Veterans Administration and the National Heart, Lung and Blood Institute. Its clinical phase has been completed, and it demonstrated 1. that the required relatively young asymptomatic population could be enrolled in the study and 2. that it could be persuaded to adhere to the protocol for 2 years; however, it was evident that intensive efforts would be required in both areas. The feasibility trial screened almost 120,000 potential subjects over a period of 16 months to randomize about 1,000 subjects at four clinical centers. These men and women were 21 to 50 years old, had diastolic pressures from 85 to 105 mm Hg as outpatients, and had no evidence of cardiovascular renal abnormalities. They were randomized in double-blind fashion into active drug therapy and placebo groups. Stepped care therapy involved 50 mg chlorthalidone (Step 1), 100 mg chlorthalidone (Step 2) and 100 chlorthalidone plus 0.25 mg reserpine (Step 3). Death, myocardial infarction, stroke, angina pectoris, and congestive heart failure were the "major" morbid events that were looked for; also recorded were "minor" morbid events consisting primarily of electrocardiographic arrhythmias. The development of significant hypertension was considered a treatment failure. Side effects were carefully tabulated in both active drug and placebo groups. The study revealed an average drop in diastolic pressure of almost 12 mm Hg for active drug group and less than half of that for the placebo group; once established 6 months after randomization, the new pressure levels persisted almost without change throughout the study. Although the feasibility trial was not designed to answer the primary question regarding the benefits of treatment, the events were tabulated for each group. A total of 12 placebo-treated subjects developed significant hypertension and were put on active drug. There was not a significant difference between the two groups in the incidence of "major" morbid events; a total of eight active and five placebo patients developed myocardial infarction or died suddenly. There, however, was an excess of arrhythmias among the active drug subjects (17 in the active group versus 8 in the placebo group on the basis of preliminary data). Finally, there were twice as many side effects and 20 times as many chemical abnormalities among the active as among the placebo subjects. A protocol for a full scale study of the benefits of pharmacologic therapy in mild hypertensives has been prepared and is ready for implementation as needed; it involves relatively minor modifications of the protocol tested in the feasibility trial.

Adult↗
PubMed1977

Randomised controlled trial of treatment for mild hypertension: design and pilot trial. Report of Medical Research Council Working Party on Mild to Moderate Hypertension.

A multicentre pilot trial to assess the feasibility of undertaking a full-scale national trial of treatment for mild to moderate hypertension has been performed and is being continued. By February 1977 over 1800 patients had entered the trial and some have been under observation for three years. The results so far show that the definitive trial is administratively and scientifically feasible and ethically justified.

Adult↗
PubMed2000

Components of variance in a group-randomized trial analysed via a random-coefficients model: the Rapid Early Action for Coronary Treatment (REACT) trial.

Rapid Early Action for Coronary Treatment (REACT) was a multisite trial testing a community intervention to reduce the delay between onset of symptoms of acute myocardial infarction (MI) and patients' arrival at a hospital emergency department. The study employed a group-randomized trial design, with ten communities randomized from within matched pairs to each of two conditions. REACT also employed continuous data collection, based on surveillance of heart attack patients in community emergency departments. They analysed their data by comparing the mean slope for delay time in the ten intervention communities to the mean slope estimated in the ten control communities. Because no estimates of slope variation were available a priori, REACT was sized using approximations based on more traditional designs. In this paper, we present the slope and residual error variances as estimated from the REACT data and examine their influence on the power of the trial post hoc. We also examine the power of the trial as it would have been given a more traditional pretest-post-test design with analysis via a comparison of the net difference in condition means pretest vs post-test.

Ambulances↗
PubMed1986

Short-term outcome in trial entrants and trial eligible patients.

Of 253 patients from nine medical centres identified with first episodes of schizophrenic illness, 17 did not achieve discharge during the period of trial recruitment. 120 entered a randomised controlled trial of neuroleptic medication and were followed-up, as were 116 who were eligible for the trial but did not enter it. Overall, 60% of the sample had relapsed within two years of discharge; age, sex, ethnic origin, duration of admission, social withdrawal before admission, and type of onset of illness were not significantly related to relapse. Relapse rates were lower on active trial or standard medication than placebo, but however assessed, outcome at this early stage was poor for many patients.

Adolescent↗
PubMed2004

Randomized trial of effect of alendronate continuation versus discontinuation in women with low BMD: results from the Fracture Intervention Trial long-term extension.

UNLABELLED: To determine the effects of continuation versus discontinuation of alendronate on BMD and markers of bone turnover, we conducted an extension trial in which 1099 older women who received alendronate in the FIT were re-randomized to alendronate or placebo. Compared with women who stopped alendronate, those continuing alendronate for 3 years maintained a higher BMD and greater reduction of bone turnover, showing benefit of continued treatment. However, among women who discontinued alendronate and took placebo in the extension, BMD remained higher, and reduction in bone turnover was greater than values at FIT baseline, showing persistence of alendronate's effects on bone. INTRODUCTION: Prior trials including the Fracture Intervention Trial (FIT) have found that therapy with alendronate increases BMD and decreases fracture risk for up to 4 years in postmenopausal women with low BMD. However, it is uncertain whether further therapy with alendronate results in preservation or further gains in BMD and if skeletal effects of alendronate continue after treatment is stopped. MATERIALS AND METHODS: We conducted a follow-up placebo-controlled extension trial to FIT (FIT long-term extension [FLEX]) in which 1099 women 60-86 years of age who were assigned to alendronate in FIT with an average duration of use of 5 years were re-randomized for an additional 5 years to alendronate or placebo. The results of a preplanned interim analysis at 3 years are reported herein. Participants were re-randomized to alendronate 10 mg/day (30%), alendronate 5 mg/day (30%), or placebo (40%). All participants were encouraged to take a calcium (500 mg/day) and vitamin D (250 IU/day) supplement. The primary outcome was change in total hip BMD. Secondary endpoints included change in lumbar spine BMD and change in markers of bone turnover (bone-specific alkaline phosphatase and urinary type I collagen cross-linked N-telopeptide). RESULTS: Among the women who had prior alendronate therapy in FIT, further therapy with alendronate (5 and 10 mg groups combined) for 3 years compared with placebo maintained BMD at the hip (2.0% difference; 95% CI, 1.6-2.5%) and further increased BMD at the spine (2.5% difference; 95% CI, 1.9-3. 1%). Markers of bone turnover increased among women discontinuing alendronate, whereas they remained stable in women continuing alendronate. Cumulative increases in BMD at the hip and spine and reductions in bone turnover from 8.6 years earlier at FIT baseline were greater for women continuing alendronate compared with those discontinuing alendronate. However, among women discontinuing alendronate and taking placebo in the extension, BMD remained higher and reduction in bone turnover was greater than values at FIT baseline. CONCLUSIONS: Compared with women who stopped alendronate after an average of 5 years, those continuing alendronate maintained a higher BMD and greater reduction of bone turnover, showing benefit of continued alendronate treatment on BMD and bone turnover. On discontinuation of alendronate therapy, rates of change in BMD at the hip and spine resumed at the background rate, but discontinuation did not result in either accelerated bone loss or a marked increase in bone turnover, showing persistence of alendronate's effects on bone. Data on the effect of continuation versus discontinuation on fracture risk are needed before making definitive recommendations regarding the optimal length of alendronate treatment.

Aged↗
PubMed1994

Prevalence and patterns of use of concomitant medications among participants in three multicenter human immunodeficiency virus type I clinical trials. AIDS Clinical Trials Group (ACTG).

Data on the prevalence and patterns of use of concomitant medications among participants in three large phase III clinical trials of zidovudine (ZDV) in human immunodeficiency virus type 1 (HIV-1) infection were analyzed. Overall, 2,801 patients reported 43,331 uses of concomitant medications. Over 85% of clinical trial participants used one or more concomitant medications at some point during the study. Patients with acquired immune deficiency syndrome (AIDS) used an average of 7.1 drugs per month. Patients with AIDS-related complex (ARC) or who were asymptomatic used relatively fewer drugs: 3.1 and 2.7 per month, respectively. Fourteen percent of patients with AIDS used more than 10 concomitant medications per month. The three most commonly utilized classes of drugs were antiinfectives (57%), analgesics or antipyretics (55%), and vitamins (47%). A total of 17% of patients overall and 30% of AIDS patients used acyclovir while on trial. Consumption of prescription drugs was greater, and "over-the-counter" drugs less, among AIDS patients. Reported use of agents not approved by the Food and Drug Administration or approved drugs used for off-label indications was infrequent. Overall use of concomitant medications did not differ across demographic subgroups when corrected for disease stage at the time of enrollment. White, non-Hispanic, homosexual and bisexual men consumed significantly more antivirals and vitamins than other trial participants. Women in all three protocols took more analgesics or antipyretics than did men.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗