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PubMed2006

Differentially variable component analysis: Identifying multiple evoked components using trial-to-trial variability.

Electric potentials and magnetic fields generated by ensembles of synchronously active neurons, either spontaneously or in response to external stimuli, provide information essential to understanding the processes underlying cognitive and sensorimotor activity. Interpreting recordings of these potentials and fields is difficult because detectors record signals simultaneously generated by various regions throughout the brain. We introduce a novel approach to this problem, the differentially variable component analysis (dVCA) algorithm, which relies on trial-to-trial variability in response amplitude and latency to identify multiple components. Using simulations we demonstrate the importance of response variability to component identification, the robustness of dVCA to noise, and its ability to characterize single-trial data. We then compare the source-separation capabilities of dVCA with those of principal component analysis and independent component analysis. Finally, we apply dVCA to neural ensemble activity recorded from an awake, behaving macaque-demonstrating that dVCA is an important tool for identifying and characterizing multiple components in the single trial.

Animals↗
PubMed2006

IMOP: randomised placebo controlled trial of outpatient cervical ripening with isosorbide mononitrate (IMN) prior to induction of labour - clinical trial with analyses of efficacy, cost effectiveness and acceptability.

BACKGROUND: There is increasing interest in carrying out pre-induction cervical ripening on an outpatient basis. However, there are concerns about the use of prostaglandins, the agents commonly used in hospital settings for this indication, because prostaglandins induce uterine contractions that may lead to fetal hypoxia. Indeed, in a recent study we demonstrated abnormalities in 9% of fetal heart rate tracings performed following prostaglandin induced cervical ripening at term. In contrast, we confirmed in the same study that isosorbide mononitrate (IMN) (administered on an inpatient basis) was both effective in inducing cervical ripening at term, and was associated with no associated fetal heart rate abnormalities. METHODS/DESIGN: The aim of this study is to determine whether IMN self administered by women on an outpatient basis improves the process of induction of labour. Specifically, we hypothesise that the use of outpatient IMN will result in a shorter inpatient stay before delivery, decreased costs to the health service and greater maternal satisfaction with ripening and induction of labour, compared with placebo treatment. In the study described here (the "IMOP" study), women scheduled for induction of labour at term, and who require pre-induction cervical ripening will be randomised to self-administer at home either IMN 40 mg, or a placebo, each vaginally, at 48 hours, 32 hours and 16 hours before scheduled hospital admission. After admission to hospital, treatment will revert to the usual induction of labour protocol. We will compare the primary outcomes of the elapsed time interval from hospital admission to vaginal delivery, the costs to the health service of induction of labour, and women's experience of induction of labour in the two groups. DISCUSSION: This trial will provide evidence on the efficacy of outpatient IMN for pre-induction cervical ripening at term. We will study a formulation of IMN which is cheap and widely available. If the treatment is effective, acceptable to women, and cost effective, it could be implemented into obstetric practice worldwide. TRIAL REGISTRATION: The trial has been registered on the International Standard Randomised Controlled Trial Number Register (ISRCTN) and given the registration number ISRTN39772441.

Journal Article↗
PubMed2006

Lead editorial: trials - using the opportunities of electronic publishing to improve the reporting of randomised trials.

This editorial introduces the new online, open access, peer-reviewed journal Trials. The journal considers manuscripts on any aspect of the design, performance, and findings of randomised controlled trials in any discipline related to health care, and also encourages the publication of protocols. Trialists will be able to provide the necessary detail for a true and complete scientific record. They will be able to communicate not only all outcome measures, as well as varying analyses and interpretations, but also in-depth descriptions of what they did and honest reflections about what they learnt. Trials also encourages articles covering generic issues related to trials, for example focussing on the design, conduct, analysis, interpretation, or reporting.

Editorial↗
PubMed2005

Trial-by-trial coupling of concurrent electroencephalogram and functional magnetic resonance imaging identifies the dynamics of performance monitoring.

Goal-directed behavior requires the continuous monitoring and dynamic adjustment of ongoing actions. Here, we report a direct coupling between the event-related electroencephalogram (EEG), functional magnetic resonance imaging (fMRI), and behavioral measures of performance monitoring in humans. By applying independent component analysis to EEG signals recorded simultaneously with fMRI, we found the single-trial error-related negativity of the EEG to be systematically related to behavior in the subsequent trial, thereby reflecting immediate behavioral adjustments of a cognitive performance monitoring system. Moreover, this trial-by-trial EEG measure of performance monitoring predicted the fMRI activity in the rostral cingulate zone, a brain region thought to play a key role in processing of response errors. We conclude that investigations of the dynamic coupling between EEG and fMRI provide a powerful approach for the study of higher order brain functions.

Adult↗
PubMed1979

The four basic types of evaluation: clinical reviews, clinical trials, program reviews, and program trials.

Four basic types of evaluation, each appropriate in a distinctive situation, are the clinical review and the clinical trial, which are concerned with the care of the individual patient, and the program review and program trial, which deal with programs or services directed at groups or populations. Evaluative reviews are primarily motivated by concern with the welfare of the specific population served, and they appraise specific activities in specific settings as a basis for decisions concerning these activities. Clinical and program trials aim to generate knowledge of more general applicability, especially concerning causal relationships between care and outcomes. The types of evaluation differ in the questions they pose and in the methods used to answer them. Failure to draw a distinction between program reviews and program trials is a frequent cause of wasteful or unhelpful evaluative studies.

Consumer Behavior↗
PubMed2003

Quantifying generalization from trial-by-trial behavior of adaptive systems that learn with basis functions: theory and experiments in human motor control.

During reaching movements, the brain's internal models map desired limb motion into predicted forces. When the forces in the task change, these models adapt. Adaptation is guided by generalization: errors in one movement influence prediction in other types of movement. If the mapping is accomplished with population coding, combining basis elements that encode different regions of movement space, then generalization can reveal the encoding of the basis elements. We present a theory that relates encoding to generalization using trial-by-trial changes in behavior during adaptation. We consider adaptation during reaching movements in various velocity-dependent force fields and quantify how errors generalize across direction. We find that the measurement of error is critical to the theory. A typical assumption in motor control is that error is the difference between a current trajectory and a desired trajectory (DJ) that does not change during adaptation. Under this assumption, in all force fields that we examined, including one in which force randomly changes from trial to trial, we found a bimodal generalization pattern, perhaps reflecting basis elements that encode direction bimodally. If the DJ was allowed to vary, bimodality was reduced or eliminated, but the generalization function accounted for nearly twice as much variance. We suggest, therefore, that basis elements representing the internal model of dynamics are sensitive to limb velocity with bimodal tuning; however, it is also possible that during adaptation the error metric itself adapts, which affects the implied shape of the basis elements.

Adaptation, Physiological↗
PubMed1991

[Preclinical trials from the standpoint of clinical trials].

The establishment of reliable preclinical test is essential for the reasonable clinical trial. As a methodology for the screening of new active anticancer agents, disease oriented strategy using human tumor cell lines has been proposed in USA. The important questions in DOS are to determine the representative cell lines of specific cancer and it is also extremely important to decide the numbers of cell lines used for the screening. CPT-11, topoisomerase I inhibitor, developed in my country has been demonstrated to be active against lung cancer cell lines compared with mice tumors such as S-180 and P-388. However, no compound is demonstrated to be clinically active so far by this methodology. The criteria for the application of clinical trial are obscure and each drug company decides empirically by themselves. We have proposed to use PEI (predictive efficacy index) for the prediction of antitumor activity of new compounds. The clinical effect of new platinum analogue well correlated with this value. We have conducted phase II trial of 5-FU + LV against NSCLC without no prior chemotherapy. No responder was observed in the trial. Augmentive effect of leucovorin on the cytotoxicity of 5-FU and FdUrd was examined in vitro against NSCLC and colon cancer cell lines. Leucovorin stimulated the cytotoxicity of both drugs only against colon cancer cell lines. We tried to predict the response rate of new platinum derivative based on the data of bioassay of patient's serum administrated with platinum compounds. The predicted response rates of 254-S were 57-67% and 16-27% against SCLC and NSCLC, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Consistency in nervous systems: trial-to-trial and animal-to-animal variations in the responses to repeated applications of a sensory stimulus in Aplysia.

What is the internal noise in a nervous system? We studied this question by determining the trial-to-trial consistency of the neuronal response in the abdominal ganglion of Aplysia californica. Because our voltage-sensitive dye recordings detected the spike activity from a large fraction of the neurons in the ganglion, these results provide a reasonably complete characterization of the consistency of the response to a sensory stimulus. The consistency of each neuron was evaluated by the number and timing of spikes in the response. The variability in the spike count was described using the coefficient of variation. The spike count variations follow a Poisson distribution, indicating that most of these variations were the result of a random process. For each neuron the reliability of the response to touch was measured in two ways; both measures indicated a broad distribution of reliabilities within the neuron population. The time of the maximum response also varied substantially in some animals. These timing variations were in part due to random processes and in part due to systematic effects (changes in activity of many neurons that were highly correlated). The time course of the activity of individual neurons was compared with the time course of the gill withdrawal. In some animals the activity of individual neurons was only poorly correlated with the behavior; in contrast, the summed activity of groups of neurons matched the behavior quite well. This implies that the behavioral output of the system may be a distributed combination of the activity of many neurons. The differences between animals were substantially larger than the trial-to-trial differences in one animal. The responses made by different preparations differed along many dimensions.

Action Potentials↗
PubMed1993

The Vermont-Oxford Trials Network: very low birth weight outcomes for 1990. Investigators of the Vermont-Oxford Trials Network Database Project.

This report describes the Vermont-Oxford Trials Network, a voluntary collaborative research network, and summarizes the outcomes and medical interventions for very low birth weight infants at participating centers in 1990. The Vermont-Oxford Trials Network included 36 centers in 1990 (11% university hospitals, 44% university affiliates, 44% nonaffiliated) with a total of 2961 infants weighing 501 to 1500 g (median 73 infants, range 5 to 172). Eighty percent of the infants were inborn and 65% were white. The overall network frequencies for selected interventions and outcomes were as follows: prenatal care, 90%; a complete course of antenatal corticosteroids, 12%; cesarean section, 56%; surfactant therapy, 49%; postnatal steroids for chronic lung disease, 16%; high-frequency ventilation, 4%; patent ductus arteriosus, 31%; necrotizing enterocolitis, 6%; bacterial sepsis, 16%; and intraventricular hemorrhage, 26%. By 28 days, 15% of the infants had died and 8% had been transferred, whereas by discharge 18% had died and 18% had been transferred. There were marked variations among the centers in the frequencies of different medical interventions and in the frequencies of various clinical outcomes. The Vermont-Oxford Trials Network is a unique collaborative research group composed of a broad range of neonatal intensive care units. During 1990 there were considerable differences among the centers in the interventions used and patient outcomes observed. The investigators plan to devote the resources of the Network to a research program of randomized trials and outcome studies so that effective interventions can be identified and the quality of neonatal intensive care can be continuously improved.

Clinical Medicine↗
PubMed1997

Why does the single neuron activity change from trial to trial during sensory-motor task?

Single neuron activities from cortical areas of a monkey were recorded while performing a sensory-motor task (a choice reaction time task). Quantitative trial-by-trial analysis revealed that the timing of peak activity exhibited large variation from trial to trial, compared to the variation in the behavioral reaction time of the task. Therefore, we developed a multi-unit dynamic neural network model to investigate the effects of structure of neural connections on the variation of the timing of peak activity. Computer simulation of the model showed that, even though the units are connected in a cascade fashion, a wide variation exists in the timing of peak activity of neurons because of parallel organization of neural network within each unit.

Animals↗
PubMed1996

Effects of hormone replacement therapy on endometrial histology in postmenopausal women. The Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial. The Writing Group for the PEPI Trial.

OBJECTIVE: To report the histological findings of the endometrium of postmenopausal women who were randomized to receive placebo, estrogen only, or one of three estrogen plus progestin (E+P) regimens in the Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial. DESIGN: A 3-year multicenter, randomized, double-masked, placebo-controlled trial. PARTICIPANTS: A total of 596 postmenopausal women aged 45 through 64 years without contraindication to hormone therapy. INTERVENTION: Participants were randomized and stratified in equal numbers to one of the following treatments in 28-day cycles: placebo, 0.625 mg/d of conjugated equine estrogens (CEE), 0.625 mg/d of CEE plus 10 mg/d of medroxyprogesterone acetate (MPA) for the first 12 days, 0.625 mg/d of CEE plus 2.5 mg/d of MPA, or 0.625 mg/d of CEE plus 200 mg/d of micronized progesterone (MP) for the first 12 days. OUTCOME MEASURE: Histology of endometrium collected at baseline, annual, or unscheduled visits by biopsy, curettage, or hysterectomy. ANALYSIS: Intention to treat. RESULTS: During follow-up women assigned to estrogen alone were more likely to develop simple (cystic), complex (adenomatous), or atypical hyperplasia than those given placebo (27.7% vs 0.8%, 22.7% vs 0.8%, and 11.8% vs 0%, respectively) for the same types of hyperplasia (P < .001). Participants administered one of the three E+P regimens had similar rates of hyperplasia as those given placebo (P = .16). The occurrence of hyperplasia was distributed evenly across the 3 years of the trial. Women taking estrogens alone also had more unscheduled biopsies (66.4% vs 8.4%; P < .001) and curettages (17.6% vs 0.8%; P < .001) than women receiving placebo. The number of surgical procedures was similar for women receiving placebo and women receiving the E+P regimens (P = .38). Of the 45 women with complex (adenomatous) or atypical hyperplasia, study medications were discontinued in all, and the biopsy results of 34 (94%) of 36 women with hyperplasia reverted to normal with progestin therapy. The remainder had dilatation and curettage (n = 2) or hysterectomy with (n = 2) or without (n = 6) prior medical therapy, or refused further biopsies (n = 1). One woman developed adenocarcinoma of the endometrium while receiving placebo. CONCLUSIONS: At a dosage of 0.625 mg, the daily administration of CEE enhanced the development of endometrial hyperplasia. Combining CEE with cyclic or continuous MPA or cyclic MP protected the endometrium from hyperplastic changes associated with estrogen-only therapy.

Biopsy↗
PubMed2001

A phase II trial of estramustine and etoposide in hormone refractory prostate cancer: A Southwest Oncology Group trial (SWOG 9407).

BACKGROUND: The combination of oral estramustine and oral etoposide has generated response rates of 40-50% in patients with hormone refractory prostate cancer in single institution trials. This study tested this regimen in a multi-institutional setting. METHODS: Fifty-five patients were accrued over a period of 4 months between 1 March 1996 and 1 July 1996. Two patients were not analyzable and two patients were ineligible. They were given an oral regimen consisting of estramustine 15 mg/kg/day (capped at 1120 mg per day) and etoposide 50 mg/M(2)/day, days 1-21 every 28 days. Patients received a median of two cycles of therapy. RESULTS: Toxicities included 11 patients (20%) with grades 3 or 4 granulocytopenia, 5 patients (10%) with grades 3 or 4 edema, and 3 patients (6%) with a thrombotic event. There were two treatment-related deaths, one as a result of anemia and the other as a result of a myocardial infarction. Of the 32 men who received at least 2 cycles of therapy, 7 men (22%) demonstrated a partial response to this regimen as measured by prostate-specific antigen (PSA) criteria of a 50% decline from pretreatment values. CONCLUSIONS: This trial demonstrates the toxicity of estramustine delivered in high dose. It also illustrates the difficulty of conducting phase II trials in prostate cancer in the cooperative group setting where the experience and comfort level of oncologists with new agents is less than that of the physicians at the institution where the therapy was developed. As the activity of this regimen with low-dose estramustine is defined, further multi-institutional studies may be warranted.

Administration, Oral↗
PubMed2001

Two-year, blinded, randomized, controlled trial of treatment of active rheumatoid arthritis with leflunomide compared with methotrexate. Utilization of Leflunomide in the Treatment of Rheumatoid Arthritis Trial Investigator Group.

OBJECTIVE: Three 6-12-month, double-blind, randomized, controlled trials have shown leflunomide (LEF; 20 mg/day, loading dose 100 mg x 3 days) to be effective and safe for the treatment of rheumatoid arthritis (RA). This analysis of the North American trial assessed whether the clinical benefit evident at month 12 was sustained over 24 months of treatment with LEF as compared with the efficacy and safety of methotrexate (MTX), an equivalent disease-modifying antirheumatic drug, at 24 months. METHODS: The year-2 cohort, comprising patients continuing into the second year of treatment with > or = 1 dose of study medication and > or = 1 followup visit after week 52, consisted of 235 patients (LEF n = 98; placebo n = 36; MTX n = 101). The mean (+/- SD) maintenance dose of LEF was 19.6 +/- 1.99 mg/day in year 2 and that of MTX was 12.6 +/- 4.69 mg/week. Statistical analyses used an intent-to-treat (ITT) approach. Statistical comparisons of the active treatments only were prospectively defined in the protocol. RESULTS: In total, 85% and 79% of LEF and MTX patients, respectively, who entered year 2 completed 24 months of treatment. From month 12 to month 24, the American College of Rheumatology improvement response rates of > or = 20% (LEF 79% versus MTX 67%; P = 0.049), > or = 50% (LEF 56% versus MTX 43%; P = 0.053), and > or = 70% (LEF 26% versus MTX 20%; P = 0.361) were sustained in both of the active treatment groups. The mean change in total Sharp radiologic damage scores at year 2 compared with year 1 and baseline (LEF 1.6 versus MTX 1.2) showed statistically equivalent sustained retardation of radiographic progression in the active treatment groups. Maximal improvements evident at 6 months in the Health Assessment Questionnaire (HAQ) disability index (HAQ DI) and the physical component score of the Medical Outcomes Survey 36-item short form were sustained over 12 months and 24 months; improvement in the HAQ DI with LEF4(-0.60) was statistically significantly superior to that with MTX (-0.37) at 24 months (P = 0.005). Over 24 months in the ITT cohort, serious treatment-related adverse events were reported in 1.6% of the LEF-treated patients and 3.7% of the MTX-treated patients. Frequently reported adverse events included upper respiratory tract infections, diarrhea, nausea and vomiting, rash, reversible alopecia, and transient liver enzyme elevations. CONCLUSION: The safety and efficacy of LEF and MTX were maintained over the second year of this 2-year trial. Both active treatments retarded radiographic progression over 24 months. LEF was statistically significantly superior to MTX in improving physical function as measured by the HAQ DI over 24 months of treatment. Results indicate that LEF is a safe and effective initial treatment for active RA, with clinical benefit sustained over 2 years of treatment without evidence of new or increased toxicity.

Adult↗
PubMed1995

Which outcome measures should be used in rheumatoid arthritis clinical trials? Clinical and quality-of-life measures' responsiveness to treatment in a randomized controlled trial.

OBJECTIVE: To determine the discriminant validity of the core set of outcome measures proposed by the American College of Rheumatology (ACR) and the Outcome Measures in Clinical Trials (OMERACT) conference committee to be used in clinical trials of rheumatoid arthritis (RA). METHODS: Utilizing data from a multicenter randomized double-blind clinical trial of low-dose cyclosporine and placebo in RA, we estimated the relative efficiency (RE) of measures to detect a treatment effect (relative to tender joint count, which was assigned a value of 1). Four pain measures (10-cm visual analog scale [VAS], 5-point categorical scale, Health Assessment Questionnaire [HAQ] pain index, Arthritis Impact Measurement Scales [AIMS] pain score) and 3 quality-of-life measures (Problem Elicitation Technique [PET], HAQ, AIMS) were compared. RESULTS: Physician and patient global measures were the most responsive instruments, although neither was statistically superior to tender joint count. Swollen joint count, grip strength, pain measured on a 10-cm VAS, and functional status as measured by the PET and HAQ were all of intermediate responsiveness. Morning stiffness, 5-point pain scale, and erythrocyte sedimentation rate were the least responsive instruments. CONCLUSION: This study provides further evidence to support the core set of outcome measures proposed by the ACR and OMERACT:

Adolescent↗
PubMed2006

Quality of life analyses in a clinical trial of DPPE (tesmilifene) plus doxorubicin versus doxorubicin in patients with advanced or metastatic breast cancer: NCIC CTG Trial MA.19.

BACKGROUND: DPPE (tesmilifene) plus doxorubicin (DOX) demonstrated a significant improvement in survival versus DOX in a phase III clinical trial in advanced breast cancer. However, DPPE is associated with unusual toxicity in the form of hallucinations, nausea and vomiting which were anticipated to impact on short-term quality of life (QOL). METHODS: Standard National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) approaches were applied as the primary method to analyze the QOL data from this trial. This includes cross-sectional comparisons, together with a global test for the QOL response rate. Sensitivity analyses were also performed for selected QOL domains and items, using other types of summary measures and statistics. RESULTS: Two hundred seventy one patients (89% of randomized) submitted the baseline QOL questionnaires and were included in the QOL analysis. No statistically significant difference in QOL response between treatment arms was found for any domain or item except nausea and vomiting (P = 0.04). Cross-sectional comparisons showed statistically significant differences for some domains/items at specific assessment times with all differences favoring the DOX alone arm. Patients on DPPE/DOX arm were significantly worse in terms of average and median pain change scores. CONCLUSION: Different analyses yielded slightly different conclusions but, in general, the QOL analyses were concordant and showed that patients on DOX alone had fewer disease and treatment related adverse events and better QOL. Interestingly, the QOL response analysis also showed that aggressive premedication regimens appear to ameliorate potential negative effects of DPPE on emesis and nausea as measured by patient assessed QOL.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Trial of Nonpharmacologic Intervention in the Elderly (TONE). Design and rationale of a blood pressure control trial.

National and international policy-making organizations advocate nonpharmacologic therapies to reduce blood pressure (BP). However, data to support such recommendations in older persons are virtually nonexistent. The Trials of Nonpharmacologic Intervention in the Elderly (TONE) is a randomized, controlled trial that will test whether weight loss or a reduced sodium (Na) intake or both can maintain satisfactory BP control, without unacceptable side effects, after withdrawal of antihypertensive drug therapy. Medication-treated hypertensives (aged 60 to 80 years) with a systolic BP less than 145 mm Hg and a diastolic BP less than 85 mm Hg who are taking one antihypertensive medication are randomly assigned to one of four groups: (1) weight loss alone, (2) reduced Na intake alone, (3) combined weight loss and reduced Na intake, or (4) usual life-style (control group). Overweight participants are randomized to one of these four groups, while nonoverweight individuals are assigned to either the reduced Na intake or the usual life-style group. The interventions, tailored to the needs of older persons, use behavioral approaches to accomplish intervention-specific goals (weight loss > or = 10 lb, daily Na intake < or = 80 mEqa). Three months after the start of intervention, antihypertensive drug therapy is withdrawn. The primary trial end point is a BP of 150/90 mm Hg or higher, resumption of antihypertensive drug therapy, or the occurrence of a BP-related clinical complication during 2 to 3 years of follow-up. It is anticipated that TONE findings may identify an effective and acceptable nonpharmacologic approach to control hypertension in the increasingly large number of older persons treated with antihypertensive drug therapy.

Aged↗
PubMed2005

Intraclass correlation coefficients for cluster randomized trials in primary care: the cholesterol education and research trial (CEART).

Cluster randomization trials are increasingly being used in primary care research. The main feature of these trials is that patients are nested within large clusters such as physician practices or communities and the intervention is applied to the cluster. This study design necessitates calculation of intraclass correlation coefficients in order to determine the required sample size. The purpose of this study is to determine intraclass correlation coefficients for a number of outcome measures at the primary care practice level. The CEART study is a randomized trial testing the effectiveness of translating ATP III guidelines into clinical practice, with primary care physician practices as the unit of randomization and patients as the unit of data collection. The intraclass correlation coefficient (ICC) was<0.02 and the design effect ranged from 1.0 to 2.3, respectively, for weight, total cholesterol, LDL, non-HDL, glucose, creatinine, and % at non-HDL goal. For smoking status, body mass index, systolic blood pressure, HDL cholesterol triglycerides, total cholesterol/HDL ratio and % at LDL goal, the ICC was 0.02-0.047 and the design effect was 2.6-4.1. The largest ICCs (0.05-0.12) and design effects (4.4-9.4) were found for height and diastolic blood pressure. These findings suggest that cluster randomization may substantially increase the sample size necessary to maintain adequate statistical power for selected outcomes such as diastolic blood pressure studies compared with simple randomization for most outcomes evaluated in this study where the design effect is small to moderate. Overall, the ICCs presented will be useful in calculating sample sizes at the primary care level.

Adult↗
PubMed2006

Quality assurance in a large clinical trials consortium: the experience of the Tuberculosis Trials Consortium.

Quality assurance (QA) is essential for data accuracy and proper evaluation of study objectives in clinical trials. The Tuberculosis Trials Consortium (TBTC)-a collaboration of 28 clinical sites and the Centers for Disease Control and Prevention-has developed a comprehensive QA program that provides quantitative assessments of performance based on clearly defined standards that are communicated to data collectors through a feedback process. The Implementation and Quality Committee of the TBTC developed a Site Evaluation Report (SER) that assesses performance measures (PMs) critical to the accomplishment of study objectives. PMs are defined, quantified, and evaluated, and goals and minimum acceptable scores are specified. Sites not meeting a PM minimum must provide an explanation and develop a plan to meet the goal. Site-specific and system-wide problems can be readily identified through this process. The SER is used prospectively for all TBTC treatment trials, and a Web site has been developed to maximize the availability and usefulness of performance data. The TBTC's comprehensive QA program is an example of a successful method for ensuring high quality, evaluable data.

Antitubercular Agents↗