PubMed Health⌕ Search

SEARCH · PubMed Health

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.

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

At least 415 records · Page 23Linked to original sources
PubMed2000

[Current status and problem of adjuvant chemotherapy for curatively resected gastric cancer].

Randomized controlled trials (RCT) on adjuvant chemotherapy for gastric cancer published in the West and Japan were reviewed. Although several small trials showed positive data, adjuvant chemotherapy for curatively resected gastric cancer has been thought to be ineffective in western countries. Results of Japanese RCTs also have not become evidence of its benefit. Despite this, suggestive data by non-predefined subset analyses of old RCTs have been misread as definitive evidence of benefit because of less understanding of clinical statistics in Japan. As a result most Japanese patients have received postoperative adjuvant chemoimmunotherapy. Recently understanding of clinical trial has spread gradually and well designed RCTs with sufficient sample size have been reported. First of all we have to determine the efficacy of adjuvant chemotherapy by carefully designed RCT using surgery alone arm as control.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Meta-analysis: an update.

A fairly new type of research, termed meta-analysis, attempts to analyze and combine the results of previous reports. In 1992 we updated our 1987 survey of 86 meta-analyses of randomized control trial reports in the english language literature with an additional 78. We evaluated the quality of these meta-analyses using a scoring method that lists 23 items in six major areas: study design, combinability, control of bias, statistical analysis, sensitivity analysis, and application of results. Of the 23 individual items, the mean number satisfactorily addressed was 7.63 +/- 2.84 (mean +/- S.D.) for 40 papers published from 1955 through 1982, 6.80 +/- 3.86 for 66 papers published from 1983 through 1986, and 11.91 +/- 4.79 for 58 papers published from 1987 through 1990 (F = 31.3, p < .001). We noted that methodology has definitely improved since our first survey of meta-analyses, but an urgent need still exists for a better search of the literature, quality evaluation of trials, and a synthesis of the results. Recently, meta-analysis has expanded to cover non-randomized studies, including evaluation of diagnostic tests and pooling of epidemiologic studies. There is growing concern for standards, and several methodologic issues remain unresolved.

Bias↗
PubMed2005

Sources of evidence for systematic reviews of interventions in diabetes.

AIMS: To analyse the effect on systematic reviews in diabetes interventions of including only trials that are indexed in medline, and to assess the impact of adding trials from other databases and the grey literature. METHODS: All systematic reviews of diabetes interventions which included a meta-analysis of randomized controlled trials, and were published since 1996, were selected. The impact on the meta-analysis of including only those trials indexed in medline, and the effect of then adding trials from other sources, was assessed. Where possible this was measured quantitatively, by redoing the meta-analysis, otherwise a qualitative estimate was made. RESULTS: Forty-four systematic reviews met our inclusion criteria. There were 120 articles reporting trial data which were not indexed in medline. These came from 52% of the reviews. In 34% of the reviews, basing a meta-analysis on a search of only medline would miss trials that could affect the result. Sources of non-medline data which had the biggest effect on the meta-analyses were journal articles from central and embase (mainly in Diabetes, Nutrition and Metabolism) and unpublished data (mainly from industry). The exceptions were journal articles on herbal medicine, mostly indexed in Chinese language databases. CONCLUSIONS: A search of only the medline database is insufficient for systematic reviews of diabetes, because in about 34% of reviews the missed trials could affect the results of the meta-analysis. It is recommended that central (on the Cochrane Library) also be searched. Scanning meeting abstracts, and seeking unpublished data are also recommended if the intervention has only recently been introduced.

Databases, Bibliographic↗
PubMed1996

How easy are randomized controlled trials in epilepsy to find on Medline? The sensitivity and precision of two Medline searches.

Recognition of the need for more scientifically acceptable review strategies is increasing. Systematic reviews have rarely been performed on randomized controlled trials (RCTs) in the field of epilepsy. We have 355 published RCTs on a database, which will be used as a data source from systematic reviews. We wished to test the sensitivity and precision of two Medline search strategies, and to identify reasons why RCTs were missed. Both a basic and a comprehensive search strategy were used to search Medline from 1966 to 1993. Three journals (Epilepsia, Epilepsy Research, Acta Neurological Scandinavica) were searched by hand. The sensitivity and precision of these Medline search strategies in these three journals was calculated. We investigated articles missed by our comprehensive search to ascertain why they had been missed. Of the 308 RCTs on the database published between 1966 and 1993, 275 were found by our comprehensive Medline search, whereas 103 were found by our basic search. The overall precision of our comprehensive and basic searches was 35 and 72%, respectively. The overall sensitivity of our comprehensive and basic searches was 86 and 66%, respectively. Our comprehensive search failed to find 16 RCTs published in the three journals searched by hand. Articles were missed because they were inadequately indexed on Medline and/or did not contain adequate methodological information in their titles or abstracts. To find all relevant trials, a search strategy must be as sensitive as possible, but this sensitivity inevitably involves loss of precision. The National Library of Medicine is addressing indexing problems with Medline, but the quality of reports also must be improved to enhance retrieval.

Abstracting and Indexing↗
PubMed2005

Do the pleiotropic effects of statins in the vasculature predict a role in inflammatory diseases?

Pleiotropic effects are now described for the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (or statins) that might have utility in the context of chronic inflammatory autoimmune disease. Here we discuss the pharmacology and established uses of statins and in this context describe potential anti-inflammatory and immune-modulatory effects. An extensive in vitro data set defines roles for statins in modifying endothelial function, particularly with respect to adhesion molecule expression and apoptosis. Broader effects on leukocyte function have now emerged including altered adhesion molecule expression, cytokine and chemokine release and modulation of development of adaptive immune responses via altered MHC class II upregulation. In vivo data in several inflammatory models, including collagen-induced inflammatory arthritis and experimental autoimmune encephalomyelitis, suggest that such effects might have immune-modulatory potential. Finally, a recent clinical trial has demonstrated immunomodulatory effects for statins in patients with rheumatoid arthritis. Together with their known vasculoprotective effects, this growing body of evidence provides compelling support for longer-term trials of statin therapy in human disease such as rheumatoid arthritis.

Animals↗
PubMed1999

Clinical guidelines in nursing, midwifery and the therapies: a systematic review.

BACKGROUND: While nursing, midwifery and professions allied to medicine (PAMs) are increasingly using clinical guidelines to reduce inappropriate variations in practice and ensure higher quality care, there have been no rigorous overviews of their effectiveness in relation to these professions. We identified 18 evaluations of guidelines which met established quality for evaluations of interventions aimed at changing professional practice. This paper describes characteristics of guidelines evaluated and the effectiveness of different dissemination and implementation strategies used. METHODS: Guideline evaluations conducted since 1975 which used a randomized controlled trial, controlled before-and-after, or interrupted time-series design, were identified using a combination of database and hand searching. FINDINGS: It is mostly impossible to tell whether the guidelines evaluated were based on evidence. The most common method of guideline dissemination was the distribution of printed educational materials. Three studies compared different dissemination and/or implementation strategies: findings suggest educational interventions may be of value in the dissemination of guidelines and confer a benefit over passive dissemination.

Allied Health Occupations↗
PubMed2005

Which resources should be used to identify RCT/CCTs for systematic reviews: a systematic review.

BACKGROUND: Systematic reviewers seek to comprehensively search for relevant studies and summarize these to present the most valid estimate of intervention effectiveness. The more resources searched, the higher the yield, and thus time and costs required to conduct a systematic review. While there is an abundance of evidence to suggest how extensive a search for randomized controlled trials (RCTs) should be, it is neither conclusive nor consistent. This systematic review was conducted in order to assess the value of different resources to identify trials for inclusion in systematic reviews. METHODS: Seven electronic databases, four journals and Cochrane Colloquia were searched. Key authors were contacted and references of relevant articles screened. Included studies compared two or more sources to find RCTs or controlled clinical trials (CCTs). A checklist was developed and applied to assess quality of reporting. Data were extracted by one reviewer and checked by a second. Medians and ranges for precision and recall were calculated; results were grouped by comparison. Meta-analysis was not performed due to large heterogeneity. Subgroup analyses were conducted for: search strategy (Cochrane, Simple, Complex, Index), expertise of the searcher (Cochrane, librarian, non-librarian), and study design (RCT and CCT). RESULTS: Sixty-four studies representing 13 electronic databases met inclusion criteria. The most common comparisons were MEDLINE vs. handsearching (n = 23), MEDLINE vs. MEDLINE+handsearching (n = 13), and MEDLINE vs. reference standard (n = 13). Quality was low, particularly for the reporting of study selection methodology. Overall, recall and precision varied substantially by comparison and ranged from 0 to 100% and 0 to 99%, respectively. The trial registries performed the best with median recall of 89% (range 84, 95) and median precision of 96.5% (96, 97), although these results are based on a small number of studies. Inadequate or inappropriate indexing was the reason most cited for missing studies. Complex and Cochrane search strategies (SS) performed better than Simple SS. CONCLUSION: Multiple-source comprehensive searches are necessary to identify all RCTs for a systematic review, although indexing needs to be improved. Although trial registries demonstrated the highest recall and precision, the Cochrane SS or a Complex SS in consultation with a librarian are recommended. Continued efforts to develop CENTRAL should be supported.

Databases, Bibliographic↗
PubMed2000

Relationship between test frequency and outcomes of anticoagulation: a literature review and commentary with implications for the design of randomized trials of patient self-management.

BACKGROUND: Patient self-management (PSM) of anticoagulation, which is primarily based upon the premise that more frequent testing will lead to tighter anticoagulation control and thus to improved clinical outcomes, is a promising model of care. The goals of this paper are (1) to describe the strength of evidence correlating more frequent testing with improved outcomes; and (2) to discuss implications of these findings for the design of randomized controlled trials (RCTs) assessing the effectiveness and cost-effectiveness of PSM. METHODS: We performed two literature reviews: one examining the strength of the relationship between time in target range (TTR) and the clinical outcomes of major bleeding and thromboembolism; and the second examining the strength of the relationship between frequency of testing and TTR. RESULTS: We found that (1) the relationship between TTR and clinical outcomes is strong, thus supporting use of TTR as a primary outcome variable; and (2) more frequent testing seems to increase TTR, although the studies supporting this latter conclusion were relatively few and not definitive. Statistical analysis suggested that a study which uses clinical event rates as its primary outcome would need to be much larger than a comparable study which is based upon TTR. CONCLUSIONS: When designing randomized trials of PSM, the design should (1) use as its control group high quality anticoagulation management rather than usual care; (2) include the maximum possible amount of self-management in the intervention group; (3) include different testing intervals in the intervention group; (4) use TTR as the primary outcome variable and event rates as a secondary outcome; and (5) base the sample size calculations upon a 5-10% absolute improvement in TTR. Additional RCTs are needed in order to determine how the promise of PSM can best be fulfilled.

Anticoagulants↗
PubMed2003

A pooled analysis of telithromycin in the treatment of community-acquired respiratory tract infections in adults.

BACKGROUND: Thirteen multinational, Phase III studies were conducted to establish the efficacy of telithromycin 800 mg once daily in the treatment of community-acquired respiratory tract infections (RTIs). PATIENTS AND METHODS: Data were analyzed from 4,743 adult patients participating across four indications: community-acquired pneumonia (CAP) of mild to moderate severity, acute exacerbations of chronic bronchitis (AECB), acute maxillary sinusitis (AMS) and tonsillitis/pharyngitis. RESULTS: Treatment with telithromycin for either 5 days (AECB, AMS and tonsillitis/pharyngitis) or 7-10 days (CAP and AMS) provided high rates of clinical and bacteriologic cure (5-day, 87.0% and 86.0%, respectively; 7 to 10-days, 90.3% and 90.5%, respectively) that were equivalent to those of a 10-day course of comparator antibacterials (86.5% and 86.5%, respectively). The clinical efficacy of telithromycin extended to high-risk CAP and AECB patients and to all key respiratory pathogens, including Streptococcus pneumoniae strains resistant to penicillin or erythromycin and atypical/intracellular pathogens. Telithromycin was generally well-tolerated across patient groups. CONCLUSION: These findings support the use of telithromycin as an effective therapy for the treatment of community-acquired RTIs.

Acute Disease↗
PubMed2006

The influence of high-efficiency particulate air filtration on mortality and fungal infection among highly immunosuppressed patients: a systematic review.

BACKGROUND: Patients with hematological malignancies who are treated with intensive chemotherapy or who receive bone marrow transplants are exposed to an increased risk of developing nosocomial fungal infections. The aim of this systematic review was to compare the effectiveness of high-efficiency particulate air (HEPA) filtration with that of non-HEPA filtration in decreasing the rates of mortality and fungal infection among patients with diagnosed hematological malignancies and neutropenia or among patients with bone marrow transplants. METHODS: Articles identified in a Medline search, guidelines, and books, as well as the bibliographies of review articles, monographs, and the articles identified by Medline, were researched. Randomized trials and observational studies comparing HEPA filtration with conventional room ventilation were selected for inclusion in the present review. RESULTS: Sixteen trials (9 with death as an outcome and 10 with fungal infection as an outcome) that compared HEPA filtration with non-HEPA filtration were selected for meta-analyses. We discovered no significant advantages of HEPA filtration in the prevention of death among patients with hematological malignancies with severe neutropenia in randomized controlled trials (RCTs; relative risk [RR], 0.86 [95% confidence interval {CI}, 0.65-1.14]) and in studies of a lower standard (non-RCTs; RR, 0.87 [95% CI, 0.60-1.25]). CONCLUSIONS: The placement in protected areas of patients with hematological malignancies with severe neutropenia or patients with bone marrow transplants appears to be beneficial, but no definitive conclusion could be drawn from the data available.

Air Microbiology↗
PubMed2005

An assessment of the methodological quality of research published in The American Journal of Sports Medicine.

BACKGROUND: Evidence-based medicine has become a popular topic in academic medicine during the past several decades and more recently in orthopaedics and sports medicine. HYPOTHESIS: Articles published in The American Journal of Sports Medicine have shown an improvement in methodological quality in 2001-2003, compared with 1991-1993. STUDY DESIGN: Systematic review. METHODS: All articles published in The American Journal of Sports Medicine during the periods 1991-1993 and 2001-2003 were reviewed and classified by type of study. The use of pertinent methodologies such as prospective data collection, randomization, blinding, and controlled studies was noted for each article. The frequency of each article type and the use of evidence-based techniques were compared across study periods. RESULTS: Case series and descriptive studies decreased during the study period, from 27.4% to 15.3% (P = .00003) and from 11.9% to 5.6% (P = .001), respectively, of articles published. Prospective cohort studies increased from 4.7% to 14.1% (P = .000005), and randomized, prospective clinical trials increased from 2.7% to 5.9% of articles (P = .04). More studies tested an explicit hypothesis (P = .0000002), used prospective data collection (P = .000003), and used blinding (P = .02), and more studies identified a funding source (P = .004). CONCLUSIONS: Overall, there was a shift toward more prospective and randomized research designs published in The American Journal of Sports Medicine during 2001-2003 compared to 1991-1993, demonstrating an improvement in the methodological quality of published research.

Case-Control Studies↗
PubMed2006

A 30 year perspective of the quality of evidence published in 25 clinical journals: signs of change?

METHODS: The quality of clinical studies published in five different specialties, over three decades was evaluated. Computerised search of the Medline database was undertaken to evaluate the articles published in 25 clinical journals in 1983, 1993, and 2003 from five different specialties (medicine, surgery, paediatrics, anaesthesia, and psychiatry). The number of randomised controlled trials (RCTs), meta-analyses, and other clinical trials (non-RCT) were noted. RESULTS: From the 27,030 articles evaluated, there were 2283 (8.4%) RCTs, 166 (0.6%) meta-analyses, and 4153 (15.4%) other clinical trials. For the proportion of RCTs, the rank order of the specialties was; anaesthesia (503; 18%), psychiatry (294; 9.6%), medicine (899; 8.1%), paediatrics (326; 6.4%), and surgery (261; 5.3%) (p<0.001). For the proportion of meta-analysis, the rank order of the specialties was; psychiatry (36; 1.2%), medicine (105; 0.9%), paediatrics (15; 0.3%), anaesthesia (6; 0.2%), and surgery (4; 0.1%) (p<0.001). Overall, from 1983 to 2003, there were increases in the proportion of RCTs (449, 5.9% to 1027, 9.6%), meta-analysis (0, 0% to 127, 1.2%), and other clinical trials (897, 12% to 1983, 19%) (p<0.001). This trend was apparent in each clinical specialty (p<0.001). CONCLUSIONS: Over the three decades evaluated, clinical trials, notably RCTs and meta-analysis form only a small proportion of articles published in prominent journals from five clinical specialties. This is notwithstanding the modest increases in the proportions of RCTs and meta-analysis over the same period.

Consensus↗
PubMed2001

Topical antibiotics for acute bacterial conjunctivitis: a systematic review.

There has been uncertainty about whether antibiotic therapy confers significant benefit in the treatment of acute bacterial conjunctivitis. This study aimed to assess the efficacy of antibiotic therapy in the management of acute bacterial conjunctivitis. Using standard Cochrane search methods, we identified double-blind randomised controlled trials in which any form of antibiotic treatment (topical, systemic or combination) had been compared with placebo in the management of acute bacterial conjunctivitis. Data extraction and analysis followed a pre-defined protocol. Meta-analysis was performed to obtain summary measures of relative risk. Six published trials were identified, of which three fulfilled the eligibility criteria for inclusion in this review. The trials were heterogeneous in terms of their inclusion and exclusion criteria, the nature of the intervention, and the outcome measures assessed. Meta-analysis indicates that acute bacterial conjunctivitis is frequently a self-limiting condition, as clinical remission occurred by days 2 to 5 in 64% (95% confidence interval (CI) = 57-71) of those treated with placebo. Treatment with antibiotics was, however, associated with significantly better rates of clinical remission (days 2 to 5: relative risk (RR) = 1.31, 95% CI = 1.11-1.55), with a suggestion that this benefit was maintained for late clinical remission (days 6 to 10: RR = 1.27, 95% CI = 1.00-1.61). Acute bacterial conjunctivitis is frequently a self-limiting condition but the use of antibiotics is associated with significantly improved rates of early clinical remission, and early and late microbiological remission. Since trials to date have been conducted in selected specialist care patient populations, generalisation of these results to a primary care-based population should be undertaken with a degree of caution.

Acute Disease↗
PubMed1995

Treatment of seasonal allergic rhinitis with fluticasone propionate aqueous nasal spray: review of comparator studies.

Studies have been conducted in the USA comparing fluticasone propionate aqueous nasal spray 200 micrograms once daily with beclomethasone dipropionate aqueous nasal spray 168 micrograms twice daily, oral terfenadine 60 mg twice daily, or oral astemizole 10 mg once daily given for 2 or 4 weeks during tree, grass or ragweed pollen seasons. All six were multicentre, randomised, placebo-controlled, double-blind, parallel-group studies. Efficacy was evaluated by patient and clinician assessments of individual nasal symptoms and overall response to therapy. Fluticasone propionate was superior to beclomethasone dipropionate in one trial according to patient evaluations of symptoms, but response to fluticasone propionate and beclomethasone dipropionate was similar in the second study. Comparisons with antihistamines showed fluticasone propionate to have greater efficacy. It was more effective than terfenadine in both trials according to evaluations by clinicians and patients. Similar findings were observed in the first astemizole trial. The second astemizole study showed superiority of fluticasone propionate over astemizole in terms of patient and clinician evaluations of overall response to therapy and occasionally in terms of symptom evaluations. There were no significant adverse effects, including effects on plasma cortisol concentrations, noted in any of these comparator studies.

Administration, Topical↗
PubMed2002

Study design, statistical method, and level of evidence in Japanese and American clinical journals.

Clinical articles published in Japanese journals are said to be characterized by poor study design, less sophisticated statistics, and producing few high-grade clinical evidences. Two American and two Japanese medical journals, published in 1990, 1993, 1996, and 1999 were compared to find out the differences regarding study design, statistical methods, and level of clinical evidence of original articles and synthetic studies. There were 1689 original articles in American and 308 in Japanese joumals. Regarding study design, American articles contributed much more to randomized controlled trials/controlled trials/clinical trials (27.9% vs. 14.3%, p=0.001), cohort studies (21.6% vs. 6.2%, p=0.001), and case-control studies (6.5% vs.0.3 %, p=0.000). Among original articles in American and Japanese journals, mean number of statistical methods used were 2.4 and 1.7 per article (p=0.000), respectively. Articles providing high grade clinical evidence (grade Ia, Ib & IIa) were much greater in proportion in American journals than Japanese journals (31.1% vs. 12.7%, p=0.001). The overall picture of Japanese medical articles seems to be improving recently, at least in terms of statistical methods toward more diversified and sophisticated way of use, compared to the previous data.

Data Interpretation, Statistical↗
PubMed2007

Prevention and early treatment of invasive fungal infection in patients with cancer and neutropenia and in stem cell transplant recipients in the era of newer broad-spectrum antifungal agents and diagnostic adjuncts.

Invasive fungal infection (IFI) is a leading cause of infection-related mortality among patients with cancer and prolonged neutropenia and among allogeneic hematopoietic stem cell transplant recipients with graft-versus-host disease. Invasive candidiasis was the principal IFI in the period predating fluconazole prophylaxis, whereas today, invasive aspergillosis and other mold infections cause the majority of deaths from fungal infection in this patient population. The changing epidemiology of IFI, in addition to advances made in antifungal therapeutics and early diagnosis of IFI, warrant a reevaluation of earlier strategies aimed at prevention and early treatment of IFI that were developed several years ago. Here, we propose that persistent neutropenic fever is nonspecific for an IFI and should not be used as the sole criterion for empirical modification in the antifungal regimen in a patient receiving mold-active prophylaxis. We explore the potential benefits and gaps in knowledge associated with employing chest CT scans and laboratory markers as diagnostic adjuncts for IFI. Finally, we discuss the implications of newer antifungal agents and diagnostic adjuncts in the design of future clinical trials to evaluate prophylaxis and early prevention strategies.

Antifungal Agents↗
PubMed1999

Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of Reporting of Meta-analyses.

BACKGROUND: The Quality of Reporting of Meta-analyses (QUOROM) conference was convened to address standards for improving the quality of reporting of meta-analyses of clinical randomised controlled trials (RCTs). METHODS: The QUOROM group consisted of 30 clinical epidemiologists, clinicians, statisticians, editors, and researchers. In conference, the group was asked to identify items they thought should be included in a checklist of standards. Whenever possible, checklist items were guided by research evidence suggesting that failure to adhere to the item proposed could lead to biased results. A modified Delphi technique was used in assessing candidate items. FINDINGS: The conference resulted in the QUOROM statement, a checklist, and a flow diagram. The checklist describes our preferred way to present the abstract, introduction, methods, results, and discussion sections of a report of a meta-analysis. It is organised into 21 headings and subheadings regarding searches, selection, validity assessment, data abstraction, study characteristics, and quantitative data synthesis, and in the results with "trial flow", study characteristics, and quantitative data synthesis; research documentation was identified for eight of the 18 items. The flow diagram provides information about both the numbers of RCTs identified, included, and excluded and the reasons for exclusion of trials. INTERPRETATION: We hope this report will generate further thought about ways to improve the quality of reports of meta-analyses of RCTs and that interested readers, reviewers, researchers, and editors will use the QUOROM statement and generate ideas for its improvement.

Authorship↗