Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Trials”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1995

Results of a randomized trial comparing intra-arterial cisplatin and intravenous PCNU for the treatment of primary brain tumors in adults: Brain Tumor Cooperative Group trial 8420A.

PURPOSE: To test the efficacy of intra-arterial (IA) cisplatin versus intravenous (IV) PCNU for treating primary brain tumors, in a randomized trial (Brain Tumor Cooperative Group [BTCG] Trial 8420A). METHODS: 311 adult patients (ages 19-79 years; median 45) with supratentorial tumors (confirmed histologically) were randomized by nine participating institutions. Patients were required to have completed radiotherapy (4500-6020 cGy to the tumor bed) before randomization. Patients were stratified as either nonprogressive (clinically and radiologically stable) or progressive. Results were analyzed for the 311 patients in the randomized population (RP), and for the 281 patients in the Valid Study Group (VSG) meeting protocol eligibility requirements. 56% of patients in the VSG had glioblastoma multiforme, 33% had other malignant glioma, and 11% had low-grade glioma. 64% were stratified as progressive. 12% had received prior chemotherapy. RESULTS: The group randomized to PCNU had the longer survival (p = 0.06 for the RP, p = 0.07 for the VSG). In the VSG, median survival was 10 months for the cisplatin group, 13 months for the PCNU group. The difference between treatment groups was significant (p < or = 0.02) when adjusted for important prognostic factors. PCNU lead to greater hematotoxicity; cisplatin lead to greater renal toxicity and some ototoxicity. Some cisplatin patients experienced complications associated with IA administration, including six cases of encephalopathy. CONCLUSION: The trial showed a survival advantage to the group randomized to PCNU, although the difference was modest. Coupled with previous BTCG results, these trails suggest that PCNU is an active drug for brain tumors.

Adult↗
PubMed2001

[Selection of subjects: a problem of clinical trials in traumatology. Selection effects and the problem of representation as exemplified by a prospective randomized trial on whiplash injuries].

INTRODUCTION: The internal and external validity of studies is endangered by many factors, such as selection of subjects for inclusion. Selection bias itself is a major problem, but remains unmentioned and probably unexamined in the majority of published clinical trials in traumatology. AIM OF THE STUDY: The aim of this investigation was to detect effects of subject selection which occurred during our own prospective intervention study. The clinical trial compared subjects with whiplash injury who were either treated by early mobilization or immobilization (soft collar). MATERIAL AND METHODS: Source population, eligible subjects, study participants and final study participants were compared for differences on various items like age, gender and further sociodemographic as well as crash related factors and clinical findings. RESULTS: Between 21.08.1997 and 30.04.1999 a total of 732 patients was examined and treated after whiplash in our trauma department. The options for inclusion were met by 453 patients. While 346 escaped from the study, 107 agreed to participate. Of these another 39 patients dropped out of the study. Selection effects were detected on two different levels, leading to distinct statistical procedures from those proposed in the study protocol. CONCLUSIONS: Uncontrolled selection effects could undermine the interpretability of the results of clinical trials. Awareness of selection effects is mandatory regarding the applicability of these results to subjects, other than those in the group of the final study participants.

Humans↗
PubMed1998

Antithrombin III in patients with severe sepsis. A randomized, placebo-controlled, double-blind multicenter trial plus a meta-analysis on all randomized, placebo-controlled, double-blind trials with antithrombin III in severe sepsis.

OBJECTIVES: To evaluate the safety and potential efficacy of antithrombin III (AT III) in reducing mortality in patients with severe sepsis. DESIGN: Prospective, randomized, placebo-controlled, double-blind, phase II, multicenter, multinational clinical trial. SETTING: Seven academic medical center intensive care units (ICU) in Belgium, Denmark, the Netherlands, Norway and Sweden. PATIENTS: 42 patients with severe sepsis who received standard supportive care and antimicrobial therapy, in addition to the administration of AT III or placebo. INTERVENTIONS: Patients received either an intravenous loading dose of 3000 IU AT III followed by a maintenance dose of 1500 IU every 12 h for 5 days or equivalent amounts of placebo. MEASUREMENTS AND RESULTS: All patients were evaluated for safety and for 30-day all-cause mortality. CONCLUSIONS: The administration of AT III was safe and well-tolerated. It was followed by a 39 % reduction in 30-day all-cause mortality (NS). The reduction in mortality was accompanied by a considerably shorter stay in the ICU. Patients treated with AT III exhibited a better performance in overall severity of illness and organ failure scores (Acute Physiology and Chronic Health Evaluation II, multiple organ failure, organ system failure), which was noticeable soon after initiation of treatment. Patients treated with AT III demonstrated a better resolution of pre-existing organ failures and a lower incidence of new organ failures during the observation period. A meta-analysis comprising this and two other double-blind, placebo-controlled trials with AT III with a total of 122 patients suffering from severe sepsis confirms the positive trend. The results of the meta-analysis demonstrate a 22.9 % reduction in 30-day all-cause mortality in patients treated with AT III. Although still too small to be confirmative, the meta-analysis clearly points to the fact that a sufficiently powered phase III trial is warranted to prove whether AT III has a beneficial role in the treatment of severe sepsis.

APACHE↗
PubMed1985

Coronary heart disease and all-causes mortality in the Multiple Risk Factor Intervention Trial: subgroup findings and comparisons with other trials.

The Multiple Risk Factor Intervention Trial (MRFIT) was a randomized primary prevention trial to test whether a special intervention (SI) program to reduce high blood pressure, elevated blood cholesterol, and/or cigarette smoking could lower coronary heart disease (CHD) mortality in middle-aged men at above average risk. After an average follow-up period of 7 years, risk factor levels were reduced substantially more in SI than in usual-care (UC) men; however, SI-UC differences in CHD mortality (7.1%) and total mortality (-2.1%) were not statistically significant. Subgroup analysis showed 35% fewer SI than UC CHD deaths (P = 0.14) but no all-causes mortality difference in men comparable to the cohort having dietary and smoking intervention in Oslo (the "Oslo-like" cohort). Among the subgroup hypertensive at entry, SI-UC differences in CHD and total mortality appeared to be heterogeneous: CHD mortality was 24% lower in SI than UC men with a normal resting ECG at baseline, but 67% higher if baseline ECG abnormalities were present (nominal P = 0.02, for difference in relative risk estimates). These findings were supported by within-group analyses and are generally consistent with results of other CHD/cardiovascular disease prevention trials. They pose a new hypothesis about possible adverse effects of diuretic therapy in a minority of the hypertensive population.

Adult↗
PubMed1989

Design, methods, and rationale 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. Dietary counseling was provided primarily in group settings and was aimed at changing participants' shopping, cooking, and eating habits related to a designated treatment assignment. The effect of dietary counseling was measured through changes in urinary excretion of sodium and potassium, changes in body weight, and changes in reported food intake based on 24-hour food records. Blood pressure changes during the 3-year course of followup were based on measurements taken at 6-month intervals from enrollment using a random-zero sphygmomanometer. This chapter provides a general description of the design and methods of the HPT and the underlying rationale for decisions affecting the design.

Adult↗
PubMed1989

Baseline characteristics 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 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 presents HPT baseline characteristics by weight stratum, clinic, and treatment group for various demographic, medical history, and nutritional characteristics, for several physiologic variables used in monitoring treatment compliance, and for blood pressure. The degree of comparability observed among treatment groups was within the range expected for the randomization procedure used.

Adult↗
PubMed1989

Quality assurance and monitoring 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 HPT procedures for training and certifying clinic staff, for data entry checks and data audits of its distributed data entry system, and for inspecting clinical equipment. Replicate analyses were performed regularly by the two arms of the Data Coordinating Center. The Food Coding Center and the Central Laboratory were evaluated by both internal and external monitoring techniques. The performance monitoring report, prepared semiannually for the governing committees of the HPT, reported on the effectiveness of quality assurance procedures and served to alert staff to developing problems.

Adult↗
PubMed1991

The Glaucoma Laser Trial (GLT): 3. Design and methods. Glaucoma Laser Trial Research Group.

The Glaucoma Laser Trial (GLT) was an investigator-initiated, grant-supported, multicenter, randomized, controlled clinical trial designed to investigate the efficacy and safety of argon laser trabeculoplasty (ALT) as an alternative to medical treatment for newly diagnosed primary open-angle glaucoma (POAG). One eye of each patient was randomly assigned to ALT followed by medical treatment if needed to control intraocular pressure (IOP). The patient's other eye was assigned to medical treatment. Medical treatment for either eye was prescribed according to a stepped sequence. Patients were followed for a minimum of 2 years. Monitoring for control of IOP and for adherence to the protocol continued throughout the followup period. This article describes the design and methods of the trial and provides a discussion of the underlying rationale for key design decisions.

Double-Blind Method↗
PubMed1994

Patient perception of a long-term clinical trial: experience using a close-out questionnaire in the Studies of Left Ventricular Dysfunction (SOLVD) Trial. SOLVD Close-out Working Group.

A close-out questionnaire was distributed to the participants in a long-term heart failure trial, Studies of Left Ventricular Dysfunction (SOLVD). The respondents' primary motivation for enrollment, positive and negative experiences, and reported changes in habitual behavior was analyzed. Seventy-four percent (N = 3522) of the eligible patients responded to the survey. The most commonly cited reason for enrollment was recommendation by the primary physician. A wish "to contribute to medical science" and "to help others" was also a frequent incentive. A majority of the respondents were satisfied with participation and would be willing to participate in a future clinical trial. Most negative experiences included transportation to and from the clinic and frequent staff changes. A significant number of the patients reported changes in their smoking habits, alcohol intake, and diet despite the absence of behavioral interventions in the study protocol. There were minor differences between attitudes and perceptions of the male and female participants. No differences were found between patients who had previously participated in a clinical trial and those who had not.

Attitude↗
PubMed1994

A pilot trial of recombinant desulfatohirudin compared with heparin in conjunction with tissue-type plasminogen activator and aspirin for acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 5 trial.

OBJECTIVES: The purpose of this study was to assess the value of recombinant desulfatohirudin (hirudin) as adjunctive therapy to thrombolysis in acute myocardial infarction. BACKGROUND: Failure to achieve initial reperfusion and reocclusion of the infarct-related artery remain major limitations of thrombolytic therapy despite aggressive regimens of heparin and aspirin. Hirudin, a direct thrombin inhibitor, has been shown in experimental models to enhance thrombolysis and reduce reocclusion. METHODS: The Thrombolysis in Myocardial Infarction (TIMI) 5 trial was a randomized, dose-ranging, pilot trial of hirudin versus heparin, given with front-loaded tissue-type plasminogen activator and aspirin to 246 patients with acute myocardial infarction. Patients received either intravenous heparin or hirudin at one of four ascending doses for 5 days. Patients underwent coronary angiography at 90 min and at 18 to 36 h, unless rescue angioplasty was performed. RESULTS: The primary end point, TIMI grade 3 flow in the infarct-related artery at 90 min and 18 to 36 h without death or reinfarction before the 18- to 36-h catheterization was achieved in 97 (61.8%) of 157 evaluable hirudin-treated patients compared with 39 (49.4%) of 79 evaluable heparin-treated patients (p = 0.07). All four doses of hirudin led to similar findings in the angiographic and clinical end points. At 90 min, TIMI grade 3 flow was present in 105 (64.8%) of 162 hirudin-treated patients compared with 48 (57.1%) of 84 heparin-treated patients (p = NS). Infarct-related artery patency (TIMI grade 2 or 3 flow) was similar in the two groups (82.1% and 78.6%, respectively). At 18 to 36 h, 129 (97.8%) of 132 hirudin-treated patients had a patent infarct-related artery compared with 58 (89.2%) of 65 heparin-treated patients (p = 0.01). Reocclusion by 18 to 36 h occurred in 2 (1.6%) of 123 hirudin-treated patients versus 4 (6.7%) of 60 heparin-treated patients (p = 0.07). Death or reinfarction occurred during the hospital period in 11 (6.8%) of 162 hirudin-treated patients compared with 14 (16.7%) of 84 heparin-treated patients (p = 0.02). Major spontaneous hemorrhage occurred in 1.2% of hirudin-treated patients versus 4.7% of heparin-treated patients (p = 0.09), and major hemorrhage at an instrumented site occurred in 16.3% and 18.6%, respectively (p = NS). CONCLUSIONS: Hirudin is a promising agent compared with heparin as adjunctive therapy with thrombolysis for acute myocardial infarction, and its evaluation in larger trials is warranted.

Adjuvants, Pharmaceutic↗
PubMed1995

Baseline characteristics of participants in phase II of the Trials of Hypertension Prevention (TOHP II). Trials of Hypertension Prevention (TOHP) Collaborative Research Group.

Phase II of the Trials of Hypertension Prevention (TOHP II) is a multicenter, controlled clinical trial designed to test whether weight loss, a reduced sodium intake, or a combination of weight loss and a reduced sodium intake will lower blood pressure (BP) and prevent the occurrence of hypertension. The study population consists of middle-aged, moderately overweight individuals with a diastolic BP between 83 and 89 mm Hg. Of the 2382 randomized participants, 816 (34%) are female and 494 (21%) are from a racial or ethnic minority background. At baseline, mean dietary intakes of sodium, based on measurements of 24-hour urinary excretion, were 199 mmol/d in men and 154 mmol/d in women. The average body mass index was 30.9 kg/m2. Across the four randomized groups, there was no substantial imbalance in the distribution of baseline variables; however, the mean age in the four groups was slightly but significantly different (range: 43.2 to 44.2 years, P = 0.02). A comparison of baseline characteristics of TOHP II participants with those of participants in three other primary prevention trials reveals a high level of mean dietary sodium intake in each study. Data reported in this article indicate that any subsequent differences in BP among the randomized groups are unlikely to result from maldistribution of known confounding variables at baseline. Finally, because of the high prevalence of overweight and excessive sodium intake in the United States, results from TOHP II should be broadly applicable to the general population.

Adult↗
PubMed2004

The Diabetic Postoperative Mortality and Morbidity (DIPOM) trial: rationale and design of a multicenter, randomized, placebo-controlled, clinical trial of metoprolol for patients with diabetes mellitus who are undergoing major noncardiac surgery.

BACKGROUND: Recent trials suggest that perioperative beta-blockade reduces the risk of cardiac events in patients with a risk of myocardial ischemia who are undergoing noncardiac surgery. Patients with diabetes mellitus are at a high-risk for postoperative cardiac morbidity and mortality. They may, therefore, benefit from perioperative beta-blockade. METHODS: The Diabetic Postoperative Mortality and Morbidity (DIPOM) trial is an investigator-initiated and -controlled, centrally randomized, double-blind, placebo-controlled, multicenter trial. We compared the effect of metoprolol with placebo on mortality and cardiovascular morbidity rates in patients with diabetes mellitus who were beta-blocker naive, >or=40 years old, and undergoing noncardiac surgery. The study drug was given during hospitalization for a maximum of 7 days beginning the evening before surgery. The primary outcome measure is the composite of all-cause mortality, acute myocardial infarction, unstable angina, or congestive heart failure leading to hospitalization or discovered or aggravated during hospitalization. Follow-up involves re-examination of patients at 6 months and collection of mortality and morbidity data via linkage to public databases. The study was powered on the basis of an estimated 30% 1-year event rate in the placebo arm and a 33% relative risk reduction in the metoprolol arm. The median follow-up period was 18 months. RESULTS: Enrollment started in July 2000 and ended in June 2002. A total of 921 patients were randomized, and 54% of these patients had known cardiac disease, hypertension, or both. CONCLUSION: The results of this study may have implications for reduction of perioperative and postoperative risk in patients with diabetes mellitus who are undergoing major noncardiac surgery.

Adrenergic beta-Antagonists↗
PubMed2000

Rationale, design, and baseline characteristics of a trial of prevention of cardiovascular and renal disease with fosinopril and pravastatin in nonhypertensive, nonhypercholesterolemic subjects with microalbuminuria (the Prevention of REnal and Vascular ENdstage Disease Intervention Trial [PREVEND IT]).

This study describes the rationale, design, and baseline characteristics of a trial to determine whether treatment with fosinopril 20 mg/day and/or pravastatin 40 mg/ day will prevent cardiovascular and renal disease in nonhypertensive (RR <160/100 mm Hg and not using antihypertensive medication) and nonhypercholesterolemic (total cholesterol <8.0 or <5.0 mmol/L in case of previous myocardial infarction and not using lipid lowering medication) men and women with persistent microalbuminuria (urinary albumin excretion >10 mg/L once in an early morning spot urine and 15 to 300 mg/24-hour at least once in two 24-hour urine collections). The Prevention of REnal and Vascular ENdstage Disease Intervention Trial is a single-center, double-blind, randomized, placebo-controlled trial with a 2 x 2 factorial design. The 864 randomized subjects will be monitored for a minimum of 4 years and a maximum of 5 years. The primary efficacy parameter is defined as the combined incidence of all-cause mortality or hospital admission for documented (1) nonfatal myocardial infarction, (2) myocardial ischemia, (3) heart failure, (4) peripheral vascular disease, (5) cerebrovascular accident and/or (6) end-stage renal disease.

Adult↗
PubMed2001

An open-label randomized trial to evaluate different therapeutic strategies of combination therapy in HIV-1 infection: design, rationale, and methods of the initio trial.

This article discusses the design of an ongoing open-label, randomized trial comparing three strategies of initial and subsequent HIV therapy in terms of long-term immunological and virological effect. The three treatment arms are (1) didanosine (ddI) plus stavudine (d4T) plus efavirenz (EFV) followed by zidovudine (ZDV) plus lamivudine (3TC) plus abacavir (ABC) plus nelfinavir (NFV); (2) ddI plus d4T plus NFV followed by ZDV plus 3TC plus ABC plus EFV; (3) ddI plus d4T plus EFV plus NFV followed by ZDV plus 3TC plus ABC plus saquinavir plus ritonavir. The primary objective is to determine whether it is best to start with a protease inhibitor (PI)-containing regimen, a non-nucleoside analogue reverse transcriptase inhibitor (NNRTI)-containing regimen, or with a regimen containing both a PI and an NNRTI. The aim is to recruit over 1000 patients followed for at least 3 years. The entry criteria are broad with no restriction on stage of disease, CD4 count, or HIV viral load. The criteria for therapeutic failure determining change of treatment are not defined and are left to the clinicians, but randomization is stratified by country and by the current criteria used for changing treatment. We describe the rationale behind various aspects of the design and discuss the complexities involved in undertaking such a large trial in HIV-infected patients from 180 clinical sites in 17 countries. Control Clin Trials 2001;22:160-175

Adult↗
PubMed2000

The AFFIRM trial: main trial and substudies-what can We expect?

The clinical categorization of patients who present with atrial fibrillation is a major determinant of the most appropriate strategy for rhythm management. For those patients with recurrent atrial fibrillation that has not become permanent the two available strategies are rhythm control and anticoagulation or rate control and anticoagulation. There is no clear evidence that one of these strategies is superior to the other. In the AFFIRM trial these two strategies are being compared to one another in a randomized trial. Patients are randomly assigned to one of the two strategies and the treating physician then uses therapies from an approved menu as clinically indicated. Both pharmacologic and nonpharmacologic therapies are used. An overview of the main study protocol is presented. The primary endpoint is total mortality but there are a number of clinically important secondary endpoints. Several substudies will explore important ancillary questions and some of these are also described. At this time over 3000 patients have been enrolled and the planned enrollment is 4300. Enrollment will end late in 1999 and the last patient enrolled will be followed for two years. The AFFIRM Trial will provide important information concerning the management of atrial fibrillation in a large portion of the patients who have this arrhythmia.

Anti-Arrhythmia Agents↗
PubMed2001

Design and rationale of the ARBITER trial (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol)--a randomized trial comparing the effects of atorvastatin and pravastatin on carotid artery intima-media thickness.

BACKGROUND: As a class, statins are remarkably effective in reducing low-density lipoprotein (LDL) cholesterol, and several of these drugs have now been shown to reduce coronary heart disease morbidity and mortality. However, several important controversies in the use of statins remain to be answered by clinical trials. For example, it is controversial whether marked cholesterol reduction to levels below 100 mg/dL would further reduce the incidence of coronary heart disease. Furthermore, concerns about differences among statins for nonlipid effects has raised the concern that the assumption of a class effect is premature until head-to-head clinical trials are completed. METHODS: Arterial Biology for the Investigation for the Treatment Effects of Reducing Cholesterol (ARBITER) is a single-center, randomized, active-controlled study comparing the efficacy of high-dose atorvastatin (80 mg/d) and pravastatin (40 mg/d) in patients being treated for either the primary or secondary prevention of coronary heart disease. This trial will enroll up to 200 patients for the primary end point of the mean change in intima-media thickness of the common carotid artery. This effect will be evaluated over a treatment duration of 12 months. Secondary end points include the effects of statin therapy on inflammatory and hemostatic markers (C-reactive protein and fibrinogen). CONCLUSION: ARBITER will provide important data on the role of marked LDL reduction and the "class effect" theory of statin therapy in cardiovascular medicine.

Atorvastatin↗
PubMed1993

Screening rules for determining blood pressure status in clinical trials. Application to the trials of hypertension prevention.

Multistage blood pressure screening rules are often used to select subjects for clinical trials. Multiple blood pressure readings are taken over successive visits, and the subject must meet eligibility criteria at each visit. In this paper, the authors present methods which depend on the distribution of the subject's underlying blood pressure values (the predictive value approach) or, alternatively, the subject's observed mean over all screening visits (the empirical predictive value approach) given the observed mean after one or more visits. The authors apply these methods to data from Phase I of the Trials of Hypertension Prevention, which attempts to identify subjects with mean diastolic blood pressures in the range 80-89 mmHg over three screening visits. The estimated efficiency of these rules is evaluated in terms of the number of clinic screening visits needed per eligible subject. Relative to reexamining all subjects at each visit (no screening), these approaches can reduce the number of visits required by 27%. This is in contrast to the standard rule in which a subject must have an observed mean diastolic blood pressure of 80-89 mmHg on each of three consecutive visits, which requires twice as many clinic visits per eligible subject as not screening. Thus, the approach presented is useful in identifying eligible subjects for clinical trials in an efficient manner.

Adult↗
PubMed1999

Randomized trial of informed consent and recruitment for clinical trials in the immediate preoperative period.

BACKGROUND: The standard process of obtaining informed consent sometimes prevents physicians or patients from participating in clinical trials, partly because they are concerned about eventual treatment allocation or the physician is concerned the patient might harbor some uncertainty about the best treatment. Alternative randomization methods have been advocated that may address these and other concerns. METHODS: After institutional ethics committee gave its approval, the authors interviewed 770 patients before operation and asked them to consider enrolling in a mock anesthesia trial. Patients were allocated randomly to one of five methods of randomization and consent: one-sided informed consent (the most common approach), prerandomized consent to experimental treatment, prerandomized consent to standard treatment, one-sided physician-modified informed consent, or one-sided patient-modified informed consent. Recruitment rates were compared and sociodemographic and perioperative predictors of recruitment were identified. RESULTS: The randomization method did not result in any significant difference in recruitment rates: one-sided informed consent, 55.6%; prerandomized consent to experimental treatment, 53.3%; prerandomized consent to standard treatment, 53%; one-sided physician-modified informed consent, 60.7%; and one-sided patient-modified informed consent, 56.7% (P = 0.66). Multivariate predictors of recruitment were patient age >45 yr (odds ratio, 1.44; 95% confidence interval [CI], 1.08 to 1.93), English-speaking at home (1.49; 1.0 to 2.21), and male researcher-male patient interaction (1.37; 1.20 to 1.57). CONCLUSIONS: No evidence emerged that alternative randomization and consent designs resulted in increased recruitment rates compared with simple one-sided informed consent for a sham anesthesia trial in patients awaiting elective surgery. Older, male patients were more likely to provide consent.

Adolescent↗