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Results for “Randomized Controlled Trials as Topic”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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PubMed2005

A sensitivity analysis of a randomized controlled trial of zinc in treatment of falciparum malaria in children.

BACKGROUND: The randomized trial has long been recognized as a means to assess the efficacy of new interventions, because the investigator can reduce or eliminate many sources of error. As such, clinical trials often do not include quantitative assessments of the extent that systematic error could affect their results. We examined the impact of different sources of bias on a randomized controlled trial of the efficacy of zinc as an adjuvant to malaria therapy in reducing time to total parasite clearance. METHODS: Using data from a previously published study, we identified two sources of bias and used the sensitivity analysis technique developed by Lash and Fink to assess the impact of each source of bias on the outcome. RESULTS: After correcting for each source of bias and reincorporating random error into our results, the point estimate of effect comparing those who received placebo to those who received zinc changed slightly (SMR changed from 0.92 to 0.90) but the 95% interval increased 22% (changing from 0.73-1.16 in the conventional analysis to 0.65-1.26 in the sensitivity analysis). CONCLUSIONS: The findings of this sensitivity analysis serve as a reminder that the frequentist confidence interval underestimates the total error, even in a randomized controlled trial. Authors of randomized controlled trial investigations ought to conduct a complete assessment of the impact of potential sources of bias in their studies. CONSORT guidelines for reporting trial results should be updated to encourage authors to assess the impact of non-random errors on their studies.

Antimalarials↗
PubMed2004

[Photodynamic therapy in AMD. Strategy for indication].

In recent years several prospective studies have dealt with the therapeutic possibilities of PDT. In consideration of lesion size and its composition, a subtly differentiated scheme of therapy has been developed. Based on essential studies, recommendations on the indication for photodynamic therapy are summarized. They are complemented by references to safety and efficacy of photodynamic therapy. Users of PDT are given a short summary of relevant studies with current recommendations, which might ease the daily procedure of indicating photodynamic therapy.

Choroidal Neovascularization↗
PubMed2002

Capecitabine as first-line treatment in colorectal cancer. Pooled data from two large, phase III trials.

The oral, tumour-selective fluoropyrimidine capecitabine represents a major new strategy for the treatment of colorectal cancer. Pooled results from two large, multicentre, open-label, phase III studies comparing oral capecitabine (1250 mg/m2 twice daily for 14 days every 3 weeks) with the Mayo Clinic regimen (5-fluorouracil [5-FU] 425 mg/m2 plus leucovorin 20 mg/m2 days 1-5, every 4 weeks) provide information on over 1200 patients receiving first-line chemotherapy for metastatic colorectal cancer. Analysis of all randomised patients demonstrated a significantly superior overall response rate as assessed by the investigator for capecitabine compared with 5-FU/leucovorin (25.7% versus 16.7%, P<0.0002), reinforcing the individual trial results. Median time to disease progression, overall survival and duration of response were equivalent in the two treatment groups. Furthermore, capecitabine showed a superior safety profile compared with 5-FU/leucovorin, with a significantly lower incidence (P<0.001) of diarrhoea, stomatitis, nausea and alopecia, together with a reduced treatment-related hospitalisation rate. In addition, the incidence of neutropenic fever/sepsis was significantly lower in patients receiving capecitabine.

Adult↗
PubMed2002

Methods of meta-analysis: an analysis.

PURPOSE OF REVIEW: To understand the principles of systematic reviewing and meta-analysis, using recent examples from the medical literature to highlight some of these points. RECENT FINDINGS: The word 'meta-analysis' is an intimidating one, and its associated jargon makes it seem incomprehensible. Actually, it is only a mathematical maneuver to add up data in a systematic review; it might be better called 'meta-addition'. The systematic review is a process of using the best available evidence to answer a particular clinical question. Data combination (usually done with meta-analysis) increases the power to see small differences and makes a more precise estimate of a treatment effect. Its major drawback is heterogeneity (the proverbial problem of adding apples and oranges). Systematic reviews have been used by medical societies to create position statements. Such statements have suggested that parenteral nutrition is far less efficacious than previously believed. Systematic reviews in some areas of nutritional support have clarified type II errors. Problems exist, however, in a number of the published meta-analyses of aspects of this therapy. SUMMARY: Especially in an era of resource restraint, we need to become more skilled at interpreting evidence from clinical research.

Clinical Trials as Topic↗
PubMed2001

Anti-TNF alpha therapy of rheumatoid arthritis: what have we learned?

Rheumatoid arthritis (RA), a systemic disease, is characterized by a chronic inflammatory reaction in the synovium of joints and is associated with degeneration of cartilage and erosion of juxta-articular bone. Many pro-inflammatory cytokines including TNF alpha, chemokines, and growth factors are expressed in diseased joints. The rationale that TNF alpha played a central role in regulating these molecules, and their pathophysiological potential, was initially provided by the demonstration that anti-TNF alpha antibodies added to in vitro cultures of a representative population of cells derived from diseased joints inhibited the spontaneous production of IL-1 and other pro-inflammatory cytokines. Systemic administration of anti-TNF alpha antibody or sTNFR fusion protein to mouse models of RA was shown to be anti-inflammatory and joint protective. Clinical investigations in which the activity of TNF alpha in RA patients was blocked with intravenously administered infliximab, a chimeric anti-TNF alpha monoclonal antibody (mAB), has provided evidence that TNF regulates IL-6, IL-8, MCP-1, and VEGF production, recruitment of immune and inflammatory cells into joints, angiogenesis, and reduction of blood levels of matrix metalloproteinases-1 and -3. Randomized, placebo-controlled, multi-center clinical trials of human TNF alpha inhibitors have demonstrated their consistent and remarkable efficacy in controlling signs and symptoms, with a favorable safety profile, in approximately two thirds of patients for up to 2 years, and their ability to retard joint damage. Infliximab (a mAB), and etanercept (a sTNF-R-Fc fusion protein) have been approved by regulatory authorities in the United States and Europe for treating RA, and they represent a significant new addition to available therapeutic options.

Animals↗
PubMed1997

Review article: critical review of meta-analyses of randomized clinical trials in hepatogastroenterology.

BACKGROUND: This review attempts to identify meta-analyses performed in hepatogastroenterology, and to assess their quality and to identify simple criteria of good quality. METHODS: Meta-analyses of randomized clinical trials in hepatogastroenterology published as full papers before 1993 were included. A quality score was defined as the sum of 27 items evaluated in each publication and coded 2 if adequate, 1 if partial and 0 if missing. Quality criteria were identified by discriminant analysis through three groups of meta-analyses defined by their quality score (poor, middle, high). RESULTS: From 1981 to 1992, 62 publications were identified, including 42% in the last 2 years. Nineteen per cent concerned peptic ulcers, 18% oesophageal varices and 6% digestive cancers. They reported 180 meta-analyses. The quality score ranged from 14 to 40, the median was 29. Twenty-five per cent of the studies obtained a score lower than 23 and 25% a score higher than 34. Several stages of meta-analysis were poorly performed: identification and selection of trials, study of trial quality, data extraction and achievement of sensitivity analyses, subgroup and indirect analyses. Some of them led to biases and questions about the validity of results. Five criteria were significantly associated with high quality: presence of a protocol, assessment of trial quality, only randomized trials pooled, achievement of sensitivity analyses, and peer-reviewed publication. CONCLUSIONS: In hepatogastroenterology, there is an exponential increase in publication of meta-analyses but their quality is heterogeneous. In particular, the control of the biases has to be better performed.

Gastrointestinal Diseases↗
PubMed1998

The adequacy of reporting randomized, controlled trials in the evaluation of antidepressants.

OBJECTIVE: To evaluate the adequacy of the reports of methodological and statistical aspects of randomized, controlled trials that evaluate antidepressant medications and the degree to which their results can be used in subsequent metaanalyses. DATA SOURCES: Randomized, controlled trials published in English that compared 2 antidepressant drugs with a placebo were reviewed. Papers were located using Medline and reference lists. DATA EXTRACTION: Each paper was evaluated using a checklist, and 3 summary criteria scores were derived: minimal, ideal, and overall. RESULTS: Only 9 of the 69 papers met the minimal criteria to be included in a metaanalysis (which would report the final sample size and an estimate of the mean and of the standard deviation); and 0 met all of the ideal criteria for reporting clinical trials. Out of a possible 100 points, the mean score for the articles was 51, and the highest score was 80. Scores were not related to the citation impact factor of the journal in which they appeared. CONCLUSIONS: Researchers must become more aware of the criteria for reporting clinical trials, and editors must insist more strenuously that these criteria be satisfied.

Antidepressive Agents↗
PubMed1998

Rational treatment of panic disorder with antidepressants.

Rational treatment of panic disorders with antidepressants rests on decisions of drug choice, dosage, and duration of treatment. In this paper, we selectively review the author's research with the standard antidepressant, imipramine, in the treatment of panic disorder with agoraphobia as it relates to practical issues. We develop general guidelines for treatment, suggest researchable ways of increasing the net effectiveness of treatment with this class of drugs, and discuss limited generalizations to the extant literature on selective serotonin reuptake inhibitors in panic disorders.

Agoraphobia↗
PubMed2002

Seamlessly expanding a randomized phase II trial to phase III.

A sequential Bayesian phase II/III design is proposed for comparative clinical trials. The design is based on both survival time and discrete early events that may be related to survival and assumes a parametric mixture model. Phase II involves a small number of centers. Patients are randomized between treatments throughout, and sequential decisions are based on predictive probabilities of concluding superiority of the experimental treatment. Whether to stop early, continue, or shift into phase III is assessed repeatedly in phase II. Phase III begins when additional institutions are incorporated into the ongoing phase II trial. Simulation studies in the context of a non-small-cell lung cancer trial indicate that the proposed method maintains overall size and power while usually requiring substantially smaller sample size and shorter trial duration when compared with conventional group-sequential phase III designs.

Adenoviridae↗
PubMed2002

Capecitabine/irinotecan in colorectal cancer: European early-phase data and planned trials.

Capecitabine (Xeloda) and irinotecan (CPT-11, Camptosar) exhibit single-agent activity in colorectal cancer, have nonoverlapping major toxicities, and exhibit a synergistic effect in tumor xenograft models. European early-phase trials of the combination in patients with metastatic colorectal cancer indicate good response rates across doses tested and manageable toxicities, with available data supporting use of a regimen of oral capecitabine at 1,000 mg/m2 twice daily on days 1 to 14 plus IV irinotecan at 250 mg/m2 on day 1 every 21 days in this setting. The European Organisation for Research and Treatment of Cancer has planned a phase III trial (EORTC 40015) comparing this regimen of capecitabine/irinotecan with infusional fluorouracil (5-FU)/leucovorin plus irinotecan in approximately 700 patients with metastatic colorectal cancer. The QUASAR (Quick and Simple and Reliable) 2 adjuvant trial will compare 5-FU/leucovorin with capecitabine/irinotecan given over 6 months as adjuvant therapy in patients with stage II/III colorectal cancer. These trials will help define the roles of this combination in the treatment of colorectal cancer.

Administration, Oral↗
PubMed2003

SysBank: a knowledge base for systematic reviews of randomized clinical trials.

The Systematic Review Bank (SysBank) is a structured knowledge base that captures information about the design, execution, and results of systematic reviews of randomized controlled trials (RCTs). The SysBank data model has been adapted from RCT Bank, a knowledge base of randomized trials, and refined using three published systematic reviews. SysBank links directly to the RCT Bank entries of studies included in the systematic review. SysBank builds upon RCT Bank to support computer-assisted evidence-based medicine.

Artificial Intelligence↗
PubMed1994

Indications and use of the Palmaz-Schatz coronary stent.

Restenosis prevention has been the 'holy grail' of contemporary interventional cardiology. Even though balloon angioplasty has become the standard treatment for ischemic syndromes, it is still plagued by a definite incidence of restenosis. This recidivism has prompted the search for newer, catheter-based modalities of treatment to address this issue. The proliferation of newer devices for intervention has increased the number of options for the interventional cardiology; however, until recently, none has had a significant impact on restenosis. The randomized trials (STRESS and BENESTENT) have both shown a significant reduction in angiographic restenosis with the Palmaz-Schatz stent in de novo coronary lesions. Nonrandomized trials suggest additional benefit in saphenous vein bypass grafts.

Angioplasty, Balloon, Coronary↗
PubMed2006

The use of inhaled formoterol in the treatment of asthma.

OBJECTIVE: To discuss the clinical efficacy and safety of formoterol when used to relieve symptoms of asthma and prevent exercise-induced bronchoconstriction (EIB). DATA SOURCES: A PubMed search was performed for articles published between 1997 and 2005 with the keywords formoterol, asthma, and long-acting beta2-adrenergic agonist, with cross-referencing to identify peer-reviewed journal articles. STUDY SELECTION: Published articles on the clinical use of formoterol for asthma or EIB were included as well as articles detailing the pharmacologic properties of the drug. To present a thorough review of the literature, published studies based on patient number, study design, or other measures of study quality were not excluded. RESULTS: Formoterol is the only long-acting beta2-adrenergic agonist that combines a rapid onset of action (within 3 minutes) with a long duration of effect (approximately 12 hours). Clinically, as recommended by asthma treatment guidelines, formoterol in conjunction with inhaled corticosteroids (ICSs) is a preferred treatment for moderate to severe persistent asthma. Significant clinical data support the use of formoterol in combination with ICSs for the treatment of asthma, with studies demonstrating improved pulmonary function and symptom scores and decreased need for maintenance ICSs and short-acting beta2-adrenergic agonists (SABAs) as relief medication. Recent studies also demonstrate that use of formoterol as needed as relief medication is associated with a prolonged time to exacerbation, improved pulmonary function, and decreased asthma symptoms. When used as monotherapy, formoterol provides protection against EIB. Clinical data also demonstrate that formoterol is safe and well tolerated even in high doses, with an adverse event profile similar to that of SABAs. CONCLUSION: Overall, formoterol is safe and effective as adjunct controller therapy for moderate and severe persistent asthma and as monotherapy for EIB.

Administration, Inhalation↗