924 resultados para Randomized Trials
Resumo:
Internet-based cognitive behavioral self-help treatment (ICBT) for anxiety disorders has shown promising results in several trials, but there is yet a lack of studies of ICBT in „real world” primary care settings. In this randomized controlled trial we recruited participants through general practitioners. The aim of the study was to examine whether treatment-as-usual (TAU) in primary care settings plus ICBT is superior to TAU alone in reducing anxiety symptoms and other outcome measures among individuals meeting diagnostic criteria of a least one of three anxiety disorders (social anxiety disorder, panic disorder with or without agoraphobia, generalized anxiety disorder). 150 adults fulfilling diagnostic criteria for a least one of the anxiety disorders according to a diagnostic interview are randomly assigned to one of the two conditions: TAU plus ICBT versus TAU. Randomization is stratified by primary disorder, medication (yes/no) and concurrent psychotherapy. ICBT consists of a transdiagnostic and tailored Internet-based self-help program for several anxiety disorders which also includes cognitive bias modification for interpretation (CBM-I). Primary outcomes are symptoms of disorder-specific anxiety measures and diagnostic status after the intervention (9 weeks). Secondary outcomes include primary outcomes at 3-month follow-up and secondary measures such as general symptomatology, depression, quality of life, adherence to ICBT and satisfaction with ICBT. The study is currently being completed. Primary results along with results for specific subgroups (e.g. primary diagnosis, concurrent medication and/or psychotherapy) will be presented and discussed.
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Monte Carlo simulation has been conducted to investigate parameter estimation and hypothesis testing in some well known adaptive randomization procedures. The four urn models studied are Randomized Play-the-Winner (RPW), Randomized Pôlya Urn (RPU), Birth and Death Urn with Immigration (BDUI), and Drop-the-Loses Urn (DL). Two sequential estimation methods, the sequential maximum likelihood estimation (SMLE) and the doubly adaptive biased coin design (DABC), are simulated at three optimal allocation targets that minimize the expected number of failures under the assumption of constant variance of simple difference (RSIHR), relative risk (ORR), and odds ratio (OOR) respectively. Log likelihood ratio test and three Wald-type tests (simple difference, log of relative risk, log of odds ratio) are compared in different adaptive procedures. ^ Simulation results indicates that although RPW is slightly better in assigning more patients to the superior treatment, the DL method is considerably less variable and the test statistics have better normality. When compared with SMLE, DABC has slightly higher overall response rate with lower variance, but has larger bias and variance in parameter estimation. Additionally, the test statistics in SMLE have better normality and lower type I error rate, and the power of hypothesis testing is more comparable with the equal randomization. Usually, RSIHR has the highest power among the 3 optimal allocation ratios. However, the ORR allocation has better power and lower type I error rate when the log of relative risk is the test statistics. The number of expected failures in ORR is smaller than RSIHR. It is also shown that the simple difference of response rates has the worst normality among all 4 test statistics. The power of hypothesis test is always inflated when simple difference is used. On the other hand, the normality of the log likelihood ratio test statistics is robust against the change of adaptive randomization procedures. ^
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Few studies have explored factors related to participation in cancer chemoprevention trials. The purpose of this dissertation was to conduct investigations in this emerging field by studying aspects of participation at three phases of cancer chemoprevention trials: at enrollment, during a placebo run-in period, and post-trial. In all three studies, subjects had a history of cancer and were at high risk of recurrence or second primary tumors.^ The first study explored correlates of enrollment in a head and neck cancer chemoprevention trial by comparing participants and eligible nonparticipants. Of 148 subjects who met the trial's preliminary eligibility criteria, 40% enrolled. In multivariate analysis, enrollment was positively associated with being male (OR 2.36) and being employed (OR 2.73). The most commonly cited reason for declining participation among nonparticipants was transportation.^ The second study examined outcomes of an eight-week placebo run-in period in a head and neck cancer chemoprevention trial. Of 391 subjects, 91.3% were randomized after the run-in. Adherence to drug capsules ranged from 0% to 120.3% (mean $\pm$ SD, 95.8% $\pm$ 15.1). In multivariate analysis, the main variable predicting run-in outcome was race; white subjects were 3.45 times more likely to be randomized than non-white subjects. Subjects with Karnofsky scores of 100 were 2.13 times more likely to be randomized than were subjects with lower scores.^ The third study used post-trial questionnaires to assess subjects' (n = 64) perceptions of participation in a cancer chemoprevention trial. The most highly rated trial benefit was the perception of potential colon cancer prevention, and the most troublesome barrier was erroneous billing for study visits. Perceived benefits were positively associated with interest in participating in future trials of the same (p = 0.05) and longer (p = 0.02) duration, and difficulty with trial pills and procedures was inversely related to interest in future placebo-controlled trials (p = 0.01).^ These are among the first behavioral studies to be completed in the rapidly growing field of cancer chemoprevention. Much work has yet to be done, however, to advance our understanding of the complex issues relating to chemoprevention trial participation. ^
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Background: Postpartum hemorrhage (PPH) remains a major killer of women worldwide. Standard uterotonic treatments used to control postpartum bleeding do not always work and are not always available. Misoprostol's potential as a treatment option for PPH is increasingly known, but its use remains ad hoc and available evidence does not support the safety or efficacy of one particular regimen. This study aimed to determine the adjunct benefit of misoprostol when combined with standard oxytocics for PPH treatment. Methods: A randomized controlled trial was conducted in four Karachi hospitals from December 2005 – April 2007 to assess the benefit of a 600 mcg dose of misoprostol given sublingually in addition to standard oxytocics for postpartum hemorrhage treatment. Consenting women had their blood loss measured after normal vaginal delivery and were enrolled in the study after losing more than 500 ml of blood. Women were randomly assigned to receive either 600 mcg sublingual misoprostol or matching placebo in addition to standard PPH treatment with injectable oxytocics. Both women and providers were blinded to the treatment assignment. Blood loss was collected until active bleeding stopped and for a minimum of one hour after PPH diagnosis. Total blood loss, hemoglobin measures, and treatment outcomes were recorded for all participants. Results: Due to a much lower rate of PPH than expected (1.2%), only sixty-one patients were diagnosed and treated for their PPH in this study, and we were therefore unable to measure statistical significance in any of the primary endpoints. The addition of 600 mcg sublingual misoprostol to standard PPH treatments does, however, suggest a trend in reduced postpartum blood loss, a smaller drop in postpartum hemoglobin, and need for fewer additional interventions. Women who bled less overall had a significantly smaller drop in hemoglobin and received fewer additional interventions. There were no hysterectomies or maternal deaths among study participants. The rate of transient shivering and fever was significantly higher among women receiving misoprostol Conclusion: A 600 mcg dose of misoprostol given sublingually shows promise as an adjunct treatment for PPH and its use should continue to be explored for its life-saving potential in the care of women experiencing PPH. Trial Registration: Clinical trials.gov, Registry No. NCT00116480
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BACKGROUND: Antiretroviral therapy has changed the natural history of human immunodeficiency virus (HIV) infection in developed countries, where it has become a chronic disease. This clinical scenario requires a new approach to simplify follow-up appointments and facilitate access to healthcare professionals. METHODOLOGY: We developed a new internet-based home care model covering the entire management of chronic HIV-infected patients. This was called Virtual Hospital. We report the results of a prospective randomised study performed over two years, comparing standard care received by HIV-infected patients with Virtual Hospital care. HIV-infected patients with access to a computer and broadband were randomised to be monitored either through Virtual Hospital (Arm I) or through standard care at the day hospital (Arm II). After one year of follow up, patients switched their care to the other arm. Virtual Hospital offered four main services: Virtual Consultations, Telepharmacy, Virtual Library and Virtual Community. A technical and clinical evaluation of Virtual Hospital was carried out. FINDINGS: Of the 83 randomised patients, 42 were monitored during the first year through Virtual Hospital (Arm I) and 41 through standard care (Arm II). Baseline characteristics of patients were similar in the two arms. The level of technical satisfaction with the virtual system was high: 85% of patients considered that Virtual Hospital improved their access to clinical data and they felt comfortable with the videoconference system. Neither clinical parameters [level of CD4+ T lymphocytes, proportion of patients with an undetectable level of viral load (p = 0.21) and compliance levels >90% (p = 0.58)] nor the evaluation of quality of life or psychological questionnaires changed significantly between the two types of care. CONCLUSIONS: Virtual Hospital is a feasible and safe tool for the multidisciplinary home care of chronic HIV patients. Telemedicine should be considered as an appropriate support service for the management of chronic HIV infection. TRIAL REGISTRATION: Clinical-Trials.gov: NCT01117675.
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Background and purpose: Trans-Tasman Radiation Oncology Group 96.05 is a prospective randomized controlled trial comparing a single 8 Gy with 20 Gy in five fractions of radiotherapy (RT) for neuropathic pain due to bone metastases. This paper summarizes the quality assurance (QA) activities for the first 234 patients (accrual target 270). Materials and methods: Independent audits to assess compliance with eligibility/exclusion criteria and appropriateness of treatment of the index site were conducted after each cohort of approximately 45 consecutive patients. Reported serious adverse events (SAEs) in the form of cord/cauda equina compression or pathological fracture developing at the index site were investigated and presented in batches to the Independent Data Monitoring Committee. Finally, source data verification of the RT prescription page and treatment records was undertaken for each of the first 234 patients to assess compliance with the protocol. Results: Only one patient was found conclusively not to have genuine neuropathic pain, and there were no detected 'geographical misses' with RT fields. The overall rate of detected infringements for other eligibility criteria over five audits (225 patients) was 8% with a dramatic improvement after the first audit. There has at no stage been a statistically significant difference in SAEs by randomization arm. There was a 22% rate of RT protocol variations involving ten of the 14 contributing centres, although the rate of major dose violations (more than +/- 10% from protocol dose) was only 6% with no statistically significant difference by randomization arm (P = 0.44). Conclusions: QA auditing is an essential but time-consuming component of RT trials, including those assessing palliative endpoints. Our experience confirms that all aspects should commence soon after study activation. Crown Copyright (C) 2003 Published by Elsevier Science Ltd. All rights reserved.
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Background: The OARSI Standing Committee for Clinical Trials Response Criteria Initiative had developed two sets of responder criteria to present the results of changes after treatment in three symptomatic domains (pain, function, and patient's global assessment) as a single variable for clinical trials (1). For each domain, a response was defined by both a relative and an absolute change, with different cut-offs with regard to the drug, the route of administration and the OA localization. Objective: To propose a simplified set of responder criteria with a similar cut-off, whatever the drug, the route or the OA localization. Methods: Data driven approach: (1) Two databases were considered The 'elaboration' database with which the formal OARSI sets of responder criteria were elaborated and The 'revisit' database. (2) Six different scenarios were evaluated: The two formal OARSI sets of criteria Four proposed scenarios of simplified sets of criteria Data from clinical randomized blinded placebo controlled trials were used to evaluate the performances of the two formal scenarios with two different databases ('elaboration' versus 'revisit') and those of the four proposed simplified scenarios within the 'revisit' database. The placebo effect, active effect, treatment effect, and the required sample arm size to obtain the placebo effect and the active treatment effect observed were the performances evaluated for each of the six scenarios. Experts' opinion approach: Results were discussed among the participants of the OMERACT VI meeting, who voted to select the definite OMERACT-OARSI set of criteria (one of the six evaluated scenarios). Results: Data driven approach: Fourteen trials totaling 1886 CA patients and fifteen studies involving 8164 CA patients were evaluated in the 'elaboration' and the 'revisit' databases respectively. The variability of the performances observed in the 'revisit' database when using the different simplified scenarios was similar to that observed between the two databases ('elaboration' versus 'revisit') when using the formal scenarios. The treatment effect and the required sample arm size were similar for each set of criteria. Experts' opinion approach: According to the experts, these two previous performances were the most important of an optimal set of responder criteria. They chose the set of criteria considering both pain and function as evaluation domain and requiring an absolute change and a relative change from baseline to define a response, with similar cut-offs whatever the drug, the route of administration or the CA localization. Conclusion: This data driven and experts' opinion approach is the basis for proposing an optimal simplified set of responder criteria for CA clinical trials. Other studies, using other sets of CA patients, are required in order to further validate this proposed OMERACT - OARSI set of criteria. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
Resumo:
Objective. To assess the measurement properties of a simple index of symptom severity in osteoarthritis (OA) of the hips and knees. Methods. Both the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the proposed new Comprehensive Osteoarthritis Test (COAT) instrument were completed weekly by 125 subjects in the context of a randomized, 12-week, 3 parallel-arm clinical trial. The reliabilities of the various scales were assessed on a weekly basis by use of Cronbach's alpha coefficients. The validity of the COAT total scale was assessed by correlation with the WOMAC total scale on a weekly basis with correlation coefficients, and in terms of the correlations between subject-level intercepts and slopes over time. The relative responsiveness of the WOMAC and COAT total scales was assessed using a multilevel (longitudinal) multivariate (WOMAC, COAT) linear model. Results. The WOMAC and COAT total scales were highly reliable (mean over weeks: WOMAC alpha = 0.98; COAT alpha = 0.97). The correlations between the WOMAC and COAT scales were very high (mean over weeks = 0.92; subject-level intercepts = 0.91, slopes = 0.88). The COAT total scale was significantly more responsive than the WOMAC total scale in the active treatment (34.8% improvement vs 26.8%; p = 0.002). Conclusion. The COAT total scale is simple to administer, reliable, valid, and responsive to treatment effects.
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The comparability of information collected through telephone interviews and information collected through mailed questionnaires has not been well studied. As part of the first phase of a randomized controlled trial of population screening for melanoma in Queensland, Australia, the authors compared histories of skin examination reported in telephone interviews and self-administered mailed questionnaires. A total of 1,270 subjects each completed a telephone interview and a mailed questionnaire 1 month apart in 1999; 564 subjects received the interview first, and 706 received the mailed questionnaire first. Agreement between the two methods was 91.2% and 88.6% for whole-body skin examination by a physician in the last 12 months and the last 3 years, respectively, and 81.9% for whole-body skin self-examination in the last 12 months. Agreement was lower for any skin self-examination. Agreement between the two methods was similar regardless of whether the interview or the questionnaire was administered first. Missing data were less frequent for interviews (0.5%) than for mailed questionnaires (3.8%). Costs were estimated at A$9.55 (US$6.21) per completed interview and A$3.01 (US$1.96) per questionnaire. The similarity of results obtained using telephone interviews and mailed questionnaires, coupled with the substantially higher cost of telephone interviews, suggests that self-administered mailed questionnaires are an appropriate method of assessing this health behavior.
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A systematic review of the literature on the effectiveness of physical interventions for lateral epicondylalgia ( tennis elbow) was carried out. Seventy six randomised controlled trials were identified, 28 of which satisfied the minimum criteria for meta-analysis. The evidence suggests that extracorporeal shock wave therapy is not beneficial in the treatment of tennis elbow. There is a lack of evidence for the long term benefit of physical interventions in general. However, further research with long term follow up into manipulation and exercise as treatments is indicated.
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Objectives: To determine whether ingestion of milk thistle affects the pharmacokinetics of indinavir. Methods: We conducted a three-period, randomized controlled trial with 16 healthy participants. We randomized participants to milk thistle or control. All participants received initial dosing of indinavir, and baseline indinavir levels were obtained (AUC(0-8)) (phase I). The active group were then given 450 mg milk-thistle extract capsules to be taken t.i.d. from day 2 to day 30. The control group received no plant extract. On day 29 and day 30, indinavir dosing and sampling was repeated in both groups as before (phase II). After a wash-out period of 7 days, indinavir dosing and sampling were repeated as before (phase III). Results: All participants completed the trial, but two were excluded from analysis due to protocol violation. There were no significant between-group differences. Active group mean AUC(0-8) indinavir decreased by 4.4% (90% CI, -27.5% to -26%, P=0.78) from phase I to phase II in the active group, and by 17.3% (90% CI, -37.3% to +9%, P=0.25) in phase III. Control group mean AUC(0-8) decreased by 21.5% (90% CI, -43% to +8%, P=0.2) from phase I to phase II and by 38.5% (90% CI, -55.3% to -15.3%, P=0.01) of baseline at phase III. To place our findings in context, milk thistle-oindinavir trials were identified through systematic searches of the literature. A meta-analysis of three milk thistle-indinavir trials revealed a non-significant pooled mean difference of 1% in AUC(0-8) (95% CI, -53% to 55%, P=0.97). Conclusions: Indinavir levels were not reduced significantly in the presence of milk thistle.