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Biomedical subjects

D Moher

Publications and source records attributed to D Moher.

At least 19 recordsLinked to original sources

Hypothermia pediatric head injury trial: the value of a pretrial clinical evaluation phase.

BACKGROUND: The utility of a pretrial clinical evaluation or run-in phase prior to conducting trials of complex interventions such as hypothermia therapy following severe traumatic brain injury in children and adolescents has not been established. METHODS: The primary objective of this study was to prospectively evaluate the ability of investigators to adhere to the clinical protocols of care including the cooling and rewarming procedures as well as management guidelines in patients with severe traumatic brain injury (Glasgow Coma Scale<or=8) treated with 24 h of hypothermia therapy. A secondary objective was to evaluate the ability of study research assistants to complete the study case report form using a procedures manual. The study was conducted at 18 sites in Canada, the United Kingdom and France prior to proceeding to a randomized controlled trial (RCT). After 2 patients were enrolled at each center, an independent clinical evaluation committee examined the process of care and the completeness of data collection. Centers were permitted to enroll patients in the RCT once they met pre-established adherence criteria. RESULTS: Seventeen of the 18 centers completed the pretrial clinical evaluation phase demonstrating compliance with study procedures and proceeded to an RCT of hypothermia therapy. One center enrolled only 1 patient in the pretrial clinical evaluation phase due to small numbers of patients with traumatic brain injury, and therefore, did not proceed to the RCT. Three centers were required to enroll more than 2 patients in the pretrial clinical evaluation phase prior to proceeding to the RCT because of problems with adherence to the clinical protocols at two centers and the training of new study personnel at another center. Of the 39 patients enrolled during the pretrial clinical evaluation phase, 8 (20.5%) died and 22 (62.9%) had a good outcome defined as normal, mild or moderate disability assessed using the Pediatric Cerebral Performance Category score at 6 months following injury. DISCUSSION: The pretrial clinical evaluation phase was useful to ensure compliance with complex hypothermia therapy and consensus-based clinical management guidelines of care successfully implemented across 17 of 18 centers. This study maneuver allowed us to complete a subsequent RCT in 225 children following severe traumatic brain injury.

Algorithms↗

Male erectile dysfunction following spinal cord injury: a systematic review.

STUDY DESIGN: Systematic review. OBJECTIVE: To review sexuality in persons with spinal cord injuries (SCIs), and to report the effectiveness of erectile interventions. METHODS: Reports from six databases (1966-2003), selected annual proceedings (1997-2002) and manufacturer's information were screened against eligibility criteria. Included reports were abstracted and data pooled from case-series reports regarding intracavernous injections and sildenafil. RESULTS: From 2127 unique reports evaluated, 49 were included. Male sexual dysfunction was addressed in these reports of several interventions (behavioural therapy, topical agents, intraurethral alprosatadil, intracavernous injections, vacuum tumescence devices, penile implants, sacral stimulators and oral medication). Penile injections resulted in successful erectile function in 90% (95% CI: 83%, 97%) of men. Sildenafil resulted in 79% (95% CI: 68%, 90%) success; the difference in efficacy was not statistically significant. Five case-series reports involving 363 participants with penile implants demonstrated a high satisfaction rate, but a 10% complication rate. CONCLUSIONS: A large body of evidence addressing sexuality in males focuses on erection. Penile injection, sildenafil and vacuum devices generally obviate the need for penile implants to address erectile dysfunction. Interventions may positively affect sexual activity in the short term. Long-term sexual adjustment and holistic approaches beyond erections remain to be studied. Rigorous study design and reporting, using common outcome measures, will facilitate higher quality research. This will positively impact patient care. SPONSORSHIP: Agency for Healthcare Research and Quality, US Department of Health and Human Services, 2101 East Jefferson Street, Rockville, MD 20852, USA.

Clinical Trials as Topic↗

[Metformin for type-2 diabetes mellitus. Systematic review and meta-analysis].

OBJECTIVE: To evaluate the efficacy of metformin against placebo, diet, oral anti-diabetics, or insulin in type 2 diabetes mellitus. DESIGN: Systematic review. DATA SOURCES: MEDLINE (1966-2003), EMBASE (1974-2003), LILACS (1986-2003), Cochrane library (Issue 3, 2003). SELECTION OF STUDIES: 29 randomized clinical trials of metformin in monotherapy, with results on mortality, morbidity, and biochemistry. EXTRACTION OF DATA: RevMan 4 computer program. Two reviewers extracted the data and evaluated the quality. MAIN VARIABLES: any clinical event related to diabetes (mortality, coronary disease, stroke, arterial disease, and retinopathy). Secondary variables: weight and biochemistry. RESULTS: 29 clinical studies with 37 comparisons of metformin were analyzed (13 with sulphonylureas, 12 with placebo, 3 with diet, 3 with thiazolidinediones, 2 with alpha-glucosidase inhibitors, 2 with insulin, and 2 with meglitinides). Metformin was more beneficial than the sulphonylureas or insulin for any clinical event associated with diabetes (relative risk [RR]=0.78; 95% confidence interval [CI], 0.65-0.94) and than diet (RR=0.74; 95% CI, 0.60-0.90). Metformin decreased glycosylated hemoglobin A1 (weighted mean difference, -1.21%; 95% CI, -1.48 to -0.94), low density lipoprotein cholesterol (weighted mean difference, -0.24; 95% CI, -0.40 to -0.09), and weight (standardized mean difference, -0.11; 95% CI, -0.18 to -0.04). Metformin was more beneficial than the placebo, diet or the thiazolidinediones on glycosylated hemoglobin A1, and than the sulphonylureas or insulin on weight. CONCLUSIONS: In the long term metformin reduces the risks of clinical events associated with diabetes. There are no long term clinical trials which compare alpha-glucosidase inhibitors, meglitinides, and thiazolidinediones with metformin, in primary results. The different treatments compared with metformin did not obtain more benefit for the secondary results evaluated.

Adult↗

Metformin monotherapy for type 2 diabetes mellitus.

BACKGROUND: Metformin is an anti-hyperglycaemic agent used for the treatment of type 2 diabetes mellitus. Type 2 diabetes may present long-term complications: micro- (retinopathy, nephropathy and neuropathy) and macrovascular (stroke, myocardial infarction and peripheral vascular disease). Two meta-analyses have been published before, although only secondary outcomes were assessed. OBJECTIVES: To assess the effects of metformin monotherapy on mortality, morbidity, quality of life, glycaemic control, body weight, lipid levels, blood pressure, insulinaemia, and albuminuria in patients with type 2 diabetes mellitus. SEARCH STRATEGY: Studies were obtained from computerised searches of multiple electronic databases and hand searches of reference lists of relevant trials identified. Date of last search: September 2003. SELECTION CRITERIA: Trials fulfilling the following inclusion criteria: Diabetes mellitus type 2, metformin versus any other oral intervention, assessment of relevant clinical outcome measures, use of random allocation. DATA COLLECTION AND ANALYSIS: Two reviewers extracted data, using a standard data extraction form. Data were summarised under a random effects model. Dichotomous data were expressed as relative risk. We calculated the risk difference (RD), and the Number Needed to Treat, when it was possible. We collected data of mean and standard deviation from changes to baseline. However many trials reported end point data. This limitation lead to the expression of the results as standardised mean differences (SMD) and an overall SMD was calculated. Heterogeneity was tested for using the Z score and the I-squared statistic. Subgroup, sensitivity analysis and meta-regression were used to explore heterogeneity. MAIN RESULTS: We included for analysis 29 trials with 37 arms (5259 participants), comparing metformin (37 arms and 2007 participants) with sulphonylureas (13 and 1167), placebo (12 and 702), diet (three and 493), thiazolidinediones (three and 132), insulin (two and 439), meglitinides (two and 208), and glucosidase inhibitors (two and 111). Nine studies reported data on primary outcomes. Obese patients allocated to intensive blood glucose control with metformin showed a greater benefit than chlorpropamide, glibenclamide, or insulin for any diabetes-related outcomes (P = 0.009), and for all-cause mortality (P = 0.03). Obese participants assigned to intensive blood glucose control with metformin showed a greater benefit than overweight patients on conventional treatment for any diabetes-related outcomes (P = 0.004), diabetes-related death (P = 0.03), all-cause mortality (P = 0.01), and myocardial infarction (P = 0.02). Patients assigned to metformin monotherapy showed a significant benefit for glycaemia control, weight, dyslipidaemia, and diastolic blood pressure. Metformin presents a strong benefit for HbA1c when compared with placebo and diet; and a moderated benefit for: glycaemia control, LDL cholesterol, and BMI or weight when compared with sulphonylureas. AUTHORS' CONCLUSIONS: Metformin may be the first therapeutic option in the diabetes mellitus type 2 with overweight or obesity, as it may prevent some vascular complications, and mortality. Metformin produces beneficial changes in glycaemia control, and moderated in weight, lipids, insulinaemia and diastolic blood pressure. Sulphonylureas, alpha-glucosidase inhibitors, thiazolidinediones, meglitinides, insulin, and diet fail to show more benefit for glycaemia control, body weight, or lipids, than metformin.

Diabetes Mellitus, Type 2↗

Fertility following spinal cord injury: a systematic review.

STUDY DESIGN: Systematic review. OBJECTIVES: To review systematically fertility of persons with spinal cord injuries (SCI) and their partners. METHODS: Reports from six databases (1966-2003), selected annual proceedings (1997-2002) and manufacturer's information were screened against eligibility criteria. Searches covered female obstetrical issues, and the efficacy of vibration and electroejaculation for males, as well as advanced fertility (AF) treatments for partners of SCI males. Data were pooled from case-series reports on SCI males' ejaculation, and pregnancies and live births for partners of SCI males. RESULTS: In all, 2,127 unique reports were evaluated, of which 66 reports were included. No studies investigated fertility in SCI females. Ejaculation interventions in the last decade resulted in response rates of 95% (95% confidence intervals (CI) 91%, 99%), with 100% response rate reported in several recent publications. A total of 13 studies (1993-2001) yielded pregnancy rates of 51% (95% CI 42%, 60%) in partners of SCI males. Of these, 11 studies (1993-2003) yielded live birth rates of 41% (95% CI 33%, 49%). CONCLUSIONS: Fertility of SCI males is extensively studied. Semen for fertility purposes can generally be obtained using vibration and electroejaculation. AF techniques are increasing pregnancy rates. Research is needed to improve sperm quality. Freezing of sperm is unlikely to significantly improve fertility rates. Fertility of SCI females is addressed only in case reports and opinion articles. The opinion that female fertility is unaffected by SCI should be further investigated using appropriate research methodology.

Birth Rate↗

A randomized trial comparing alternative approaches to prenatal diagnosis counseling in advanced maternal age patients.

Prenatal diagnosis (PND) is offered routinely as part of pregnancy care to a large number of women at increased risk of fetal anomalies. Despite an extraordinary growth in the use of PND and significant resource allocation, few studies have examined outcomes of PND counseling, and virtually no research has evaluated the relative efficacy of various approaches to genetic counseling. This study was a randomized trial that compared which counseling methods - individual, group, and use of a decision aid - are effective in PND counseling for women of advanced maternal age (>/=35 years) and their partners. Three hundred and fifty-two women and 225 partners completed pre- and post-intervention questionnaires assessing changes in knowledge, decisional conflict, state anxiety, satisfaction, use of PND, and pregnancy outcomes. All participants showed a significant increase in knowledge and a decrease in decisional conflict post intervention. Those in the group intervention showed a significantly greater increase in knowledge than those in the individual counseling intervention. While high levels of satisfaction were reported by all, those in individual counseling were significantly more satisfied than those receiving group counseling or the decision aid. This study has shown unique benefits with each type of intervention such that women and their partners preferred individual genetic counseling, while they learned best in group-counseling sessions, and experienced the least decisional conflict regarding genetic testing with a decision aid.

Adult↗

Celiac disease.

Explore the source record for details and available documents.

Adult↗

[Reporting studies of diagnostic accuracy according to a standard method; the Standards for Reporting of Diagnostic Accuracy (STARD)].

The objective of the 'Standards for Reporting of Diagnostic Accuracy' (STARD) initiative is to improve the reporting of studies of diagnostic accuracy, so as to allow readers to assess the potential for bias in a study and to evaluate the generalibility of its results. The group searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies. This was used to draw up a list of potential items. During a consensus meeting, a group of researchers, medical journal editors, and members of professional organisations reduced this list to a usable checklist. Wherever possible, evidence from the literature was used to justify the decisions made. The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which a list of 75 potential items was extracted. At the consensus meeting, participants shortened the list to a 25-item checklist. A generic flow diagram was drawn up to provide guidance on the method for including patients, the order in which tests were to be conducted and the number of patients to undergo the test being evaluated, the reference standard, or both. A scientific publication can only be assessed when the reporting is both correct and complete. Use of the checklist and flow diagram will improve the quality of reports produced, to the advantage of clinicians, researchers, reviewers, journal editors and other interested parties.

Algorithms↗

Low molecular weight heparins versus unfractionated heparin for acute coronary syndromes.

BACKGROUND: Acute coronary syndromes (ACS) are an important source of morbidity and mortality. Despite weak evidence for the use of unfractionated heparin (UFH) for acute coronary syndromes it is considered an accepted treatment for unstable angina and non-ST segment elevation myocardial infarction (MI). However, evidence suggests low molecular weight heparins (LMWH) are safer and more effective than UFH in the treatment and prevention of other thrombotic disorders. OBJECTIVES: To assess the effects of LMWH compared to UFH for acute coronary syndromes. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (the Cochrane Library issue 4, 2000), MEDLINE (January 1966 to December 2000), EMBASE (1980 to December 2000) and CINAHL (1982 to December 2000) and reference lists of articles. Authors of all include studies and pharmaceutical industry representatives were contacted to determine if unpublished studies which met the inclusion criteria were available. SELECTION CRITERIA: Randomized controlled trials of subcutaneous LMWH versus intravenous UFH in people with acute coronary syndromes (unstable angina or non-ST segment elevation MI). DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed quality of studies. Data were extracted independently by two reviewers. Study authors were contacted to verify and clarify missing data. MAIN RESULTS: We identified 27 potentially relevant studies, 7 studies (11,092 participants) were included in this review. We found no evidence for difference in overall mortality between the groups treated with LMWH and UFH (RR = 1.0; 95% CI: 0.69, 1.44). Some pooled outcomes showed some evidence of heterogeneity, few of the pooled outcomes were statistically heterogeneous most were homogeneous. LMWH reduced the occurrence of MI (RR = 0.83; 95% CI: 0.70, 0.99) and the need for revascularization procedures (RR = 0.88; 95% CI: 0.82, 0.95). We found no evidence for difference in occurrence of recurrent angina (RR = 0.83; 95% CI: 0.68, 1.02), major bleeds (RR = 1.00; 95% CI: 0.80, 1.24) or minor bleeds (RR = 1.40; 95% CI: 0.66, 2.90). A decrease in the incidence of thrombocytopenia (RR = 0.64; 95% CI: 0.44, 0.94) was observed for patients given LMWH. From these results, 125 patients need to be treated with LMWH to prevent 1 additional MI and 50 patients need to be treated to prevent 1 revascularization procedure. Insufficient data exist to compare different types of LMWH. REVIEWER'S CONCLUSIONS: LMWH and UFH had similar risk of mortality, recurrent angina, and major or minor bleeding but LMWH had decreased risk of MI, revascularization and thrombocytopenia. New Trials with longer follow up are required.

Angina, Unstable↗

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

AIM: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the general isability of its results. METHODS: The standards for reporting of diagnostic accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organisations shortened this list during a 2 day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, by using evidence whenever available. A prototype of a flow diagram provides information about the method of recruitment of patients, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard, or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of clinicians, researchers, reviewers, journals, and the public.

Algorithms↗

The inclusion of reports of randomised trials published in languages other than English in systematic reviews.

OBJECTIVE: To assemble a large dataset of language restricted and language inclusive systematic reviews, including both conventional medicinal (CM) and complementary and alternative medicine (CAM) interventions. To then assess the quality of these reports by considering and comparing different types of systematic reviews and their associated RCTs; CM and CAM interventions; the effect of language restrictions compared with language inclusions, and whether these results are influenced by other issues, including statistical heterogeneity and publication bias, in the systematic review process. DATA SOURCES: MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews and the Centralised Information Service for Complementary Medicine. REVIEW METHODS: Three types of systematic reviews were included: language restricted; language inclusive/English language (EL) reviews that searched RCTs in languages other than English (LOE) but did not find any and, hence, could not include any, in the quantitative data synthesis; and systematic reviews that searched for RCTs in LOE and included them in the quantitative data synthesis. Fisher's exact test was applied to compare the three different types of systematic reviews with respect to their reporting characteristics and the systematic review quality assessment tool. The odds ratio of LOE trials versus EL trials was computed for each review and this information was pooled across the reviews to examine the influence that language of publication and type of intervention (CM, CAM) have on the estimates of intervention effect. Several sensitivity analyses were performed. RESULTS: The LOE RCTs were predominantly in French and German. Language inclusive/LOE systematic reviews were of the highest quality compared with the other types of reviews. The CAM reviews were of higher quality compared with the CM reviews. There were only minor differences in the quality of reports of EL RCTs compared with the eight other languages considered. However, there are inconsistent differences in the quality of LOE reports depending on the intervention type. The results, and those reported previously, suggest that excluding reports of RCTs in LOE from the analytical part of a systematic review is reasonable. Because the present research and previous efforts have not included every type of CM RCT and the resulting possibility of the uncertainty as to when bias will be present by excluding LOE, it is always prudent to perform a comprehensive search for all evidence. This result only applies to reviews investigating the benefits of CM interventions. This does not imply that systematic reviewers should neglect reports in LOE. We recommend that systematic reviewers search for reports regardless of the language. There may be merit in including them in some aspects of the review process although this decision is likely to depend on several factors, including fiscal and other resources being available. Language restrictions significantly shift the estimates of an intervention's effectiveness when the intervention is CAM. Here, excluding trials reported in LOE, compared with their inclusion, resulted in a reduced intervention effect. The present results do not appear to be influenced by statistical heterogeneity and publication bias. CONCLUSIONS: With the exception of CAM systematic reviews, the quality of recently published systematic reviews is less than optimal. Language inclusive/LOE systematic reviews appear to be a marker for a better quality systematic review. Language restrictions do not appear to bias the estimates of a conventional intervention's effectiveness. However, there is substantial bias in the results of a CAM systematic review if LOE reports are excluded from it.

Complementary Therapies↗

How efficacious and safe is short-acting methylphenidate for the treatment of attention-deficit disorder in children and adolescents? A meta-analysis.

BACKGROUND: Numerous small clinical trials have been carried out to study the behaviourally defined efficacy and safety of short-acting methylphenidate compared with placebo for attention-deficit disorder (ADD) in individuals aged 18 years and less. However, no meta-analyses that carefully examined these questions have been done. We reviewed the behavioural evidence from all the randomized controlled trials that compared methylphenidate and placebo, and completed a meta-analysis. METHODS: We searched several electronic sources for articles published between 1981 and 1999: MEDLINE, EMBASE, PsychINFO, ERIC, CINAHL, HEALTHSTAR, Biological Abstracts, Current Contents and Dissertation Abstracts. The Cochrane Library Trials Registry and Current Controlled Trials were also consulted. A study was considered eligible for inclusion if it entailed the following: a placebo-controlled randomized trial that involved short-acting methylphenidate and participants aged 18 years or less at the start of the trial who had received any primary diagnosis of ADD that was made in a systematic and reproducible way. RESULTS: We included 62 randomized trials that involved a total of 2897 participants with a primary diagnosis of ADD (e.g., with or without hyperactivity). The median age of trial participants was 8.7 years, and the median "percent male" composition of trials was 88.1%. Most studies used a crossover design. Using the scores from 2 separate indices, this collection of trials exhibited low quality. Interventions lasted, on average, 3 weeks, with no trial lasting longer than 28 weeks. Each primary outcome (hyperactivity index) demonstrated a significant effect of methylphenidate (effect size reported by teacher 0.78, 95% confidence interval [CI] 0.64-0.91; effect size reported by parent 0.54, 95% CI 0.40-0.67). However, these apparent beneficial effects are tempered by a strong indication of publication bias and the lack of robustness of the findings, especially those involving core ADD features. Methylphenidate also has an adverse event profile that requires consideration. For example, clinicians only need to treat 4 children to identify an episode of decreased appetite. INTERPRETATION: Short-acting methylphenidate has a statistically significant clinical effect in the short-term treatment of individuals with a diagnosis of ADD aged 18 years and less. However, the extension of this placebo-controlled effect beyond 4 weeks of treatment has not been demonstrated. Exact knowledge of the extent and definition of the short-term behavioural usefulness of methylphenidate is questioned.

Adolescent↗

The CONSORT statement: revised recommendations for improving the quality of reports of parallel group randomized trials.

To comprehend the results of a randomized controlled trial (RCT), readers must understand its design, conduct, analysis and interpretation. That goal can only be achieved through complete transparency from authors. Despite several decades of educational efforts, the reporting of RCTs needs improvement. Investigators and editors developed the original CONSORT (Consolidated Standards of Reporting Trials) statement to help authors improve reporting by using a checklist and flow diagram. The revised CONSORT statement presented in this paper incorporates new evidence and addresses some criticisms of the original statement.The checklist items pertain to the content of the Title, Abstract, Introduction, Methods, Results and Discussion. The revised checklist includes 22-items selected because empirical evidence indicates that not reporting the information is associated with biasedestimates of treatment effect or the information is essential to judge the reliability or relevance of the findings. We intended the flow diagram to depict the passage of participants through an RCT. The revised flow diagram depicts information from four stages of a trial (enrollment, intervention allocation, follow-up, and analysis). The diagram explicitly includes the number of participants, for each intervention group, included in the primary data analysis. Inclusion of these numbers allows the reader to judge whether the authors have performed an intention-to-treat analysis.In sum, the CONSORT statement is intended to improve the reporting of an RCT, enabling readers to understand a trial's conduct and to assess the validity of its results.

Humans↗

The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials.

To comprehend the results of a randomized controlled trial (RCT), readers must understand its design, conduct, analysis, and interpretation. That goal can be achieved only through complete transparency from authors. Despite several decades of educational efforts, the reporting of RCTs needs improvement. Investigators and editors developed the original CONSORT (Consolidated Standards of Reporting Trials) statement to help authors improve reporting by using a checklist and flow diagram. The revised CONSORT statement presented in this article incorporates new evidence and addresses some criticisms of the original statement. The checklist items pertain to the content of the Title, Abstract, Introduction, Methods, Results, and Comment. The revised checklist includes 22 items selected because empirical evidence indicates that not reporting the information is associated with biased estimates of treatment effect or because the information is essential to judge the reliability or relevance of the findings. We intended the flow diagram to depict the passage of participants through an RCT. The revised flow diagram depicts information from 4 stages of a trial (enrollment, intervention allocation, follow-up, and analysis). The diagram explicitly includes the number of participants, according to each intervention group, included in the primary data analysis. Inclusion of these numbers allows the reader to judge whether the authors have performed an intention-to-treat analysis. In sum, the CONSORT statement is intended to improve the reporting of an RCT, enabling readers to understand a trial's conduct and to assess the validity of its results.

Publishing↗