Biomedical subjects

David Moher

Publications and source records attributed to David Moher.

At least 55 records · Page 3Linked to original sources

PubMed2004

Assisted reproductive technology and the incidence of ovarian cancer: a meta-analysis.

OBJECTIVE: To systematically evaluate the available literature regarding the relationship between assisted reproductive technology and ovarian cancer. DATA SOURCES: Computerized search of 6 databases from 1966 (or closest) to present: Cochrane Controlled Trials Register, Cancerlit, CINHAL, Current Contents, PubMed in process (formerly called PreMEDLINE), and MEDLINE. We collected references from the bibliographies of reviews, original research articles, content experts, and conference proceedings to find published and unpublished literature. METHODS OF STUDY SELECTION: Case-control and cohort studies are included. The population of interest is treated infertile women, the control population is untreated infertile women, and the intervention or exposure of interest includes the following fertility medications: clomiphene citrate, gonadotropins, human chorionic gonadotropin, and gonadotropin releasing hormone agonists. The primary outcome is incident, primary ovarian cancer. Three cohort and 7 case-control studies were included in the quantitative analyses. TABULATION, INTEGRATION, AND RESULTS: The Newcastle-Ottawa Quality Assessment Scales were used. Two investigators independently extracted study methods, sources of bias, and outcomes. The following information was recorded: publication information, subject characteristics, intervention information and outcomes. Studies combined were sufficiently homogeneous for quantitative summary. Case-control and cohort data showed a significantly elevated risk for exposure of infertility medications and ovarian cancer in subjects who underwent assisted reproductive technology compared with general population controls (1.52; 95% confidence interval [CI] 1.18 to 1.97). When cases of ovarian cancer were compared with infertile controls for exposure to infertility medications, the odds ratio (0.99; 95% CI 0.67, 1.45) was not elevated. However, cohort data comparing outcome in treated infertile patients with untreated infertile patients suggests that treated patients may tend to a lower incidence of ovarian cancer-odds ratio = 0.67 (95% CI 0.32, 1.41). CONCLUSION: Ovarian cancer does not appear to be increased in treated infertile patients versus untreated infertile patients. Treated infertile patients may have a lower incidence of ovarian cancer than untreated infertile patients.

Adolescent↗

PubMed2004

Determining the reporting quality of RCTs in clinical pharmacology.

BACKGROUND: The Consolidated Standards for Reporting Trials (CONSORT) are recommendations for improving the quality of reports of randomized controlled trials (RCTs). OBJECTIVE: To determine the extent to which clinical pharmacology journals implement specific CONSORT recommendations. DESIGN AND SETTING: Analysis of RCTs published between May 2002 and May 2003 in four clinical pharmacology journals. MAIN OUTCOME MEASURES: Proportion of RCTs that published a participant flow diagram and that reported on randomization and restriction methods, allocation concealment, blinding, intention-to-treat analysis, ethical considerations, adverse events and source of funding. RESULTS: Of 482 clinical trials, 193 were RCTs. Healthy participants were involved in 129 [66.8%, 95% confidence interval (CI) 59.9, 73.1] trials, patients who required treatment in 61 (31.6%, 95% CI 25.4, 38.4) trials and both in three (1.6%, 95% CI 0.5, 4.4) trials. The following items were infrequently reported: sequence generation (17%), allocation concealment (3%), use of restriction (16%), description of blinding (26%), and flow diagrams of study participants (2%). In contrast, the following areas were often reported: use of intention-to-treat analysis (79%), description of withdrawals (92.2%) and description of adverse events (71%), ethics review (94%) and informed consent (95%). Sources of funding were reported in 56% of studies. CONCLUSION: The use of the selected CONSORT items is limited in these journals, possibly as many items may not be relevant to the types of studies published in clinical pharmacology journals. Further efforts are required to determine the applicability of CONSORT to RCTs in clinical pharmacology.

Humans↗

PubMed2003

A randomized trial of aspirin on the risk of embolic events in patients with infective endocarditis.

OBJECTIVES: This study examined the effect of aspirin on the risk of embolic events in infective endocarditis (IE). BACKGROUND: Embolism is a major complication of IE, and studies in animal models have shown that platelet inhibition with aspirin can lead to more rapid vegetation resolution and a lower rate of embolic events. METHODS: We conducted a randomized, double-blinded, placebo-controlled trial of aspirin treatment (325 mg/day) for four weeks in patients with IE to test the hypothesis that the addition of aspirin would reduce the incidence of clinical systemic embolic events. Patients with perivalvular abscess were excluded. Serial cerebral computed tomograms and transesophageal echocardiograms were obtained in a subset of patients. RESULTS: During the four-year study period, 115 patients were enrolled: 60 assigned to aspirin and 55 assigned to placebo. Embolic events occurred in 17 patients (28.3%) on aspirin and 11 patients (20.0%) on placebo, with an odds ratio (OR) of 1.62 (95% confidence interval [CI] 0.68 to 3.86, p = 0.29). There was a trend toward a higher incidence of bleeding in the patients taking aspirin versus placebo (OR 1.92, 95% CI 0.76 to 4.86, p = 0.075). Development of new intracranial lesions was similar in both groups. Aspirin had no effect on vegetation resolution and valvular dysfunction. CONCLUSIONS: In endocarditis patients already receiving antibiotic treatment, the addition of aspirin does not appear to reduce the risk of embolic events and is likely associated with an increased risk of bleeding. Aspirin is not indicated in the early management of patients with IE.

Aged↗

PubMed2003

Identifying null meta-analyses that are ripe for updating.

BACKGROUND: As an increasingly large number of meta-analyses are published, quantitative methods are needed to help clinicians and systematic review teams determine when meta-analyses are not up to date. METHODS: We propose new methods for determining when non-significant meta-analytic results might be overturned, based on a prediction of the number of participants required in new studies. To guide decision making, we introduce the "new participant ratio", the ratio of the actual number of participants in new studies to the predicted number required to obtain statistical significance. A simulation study was conducted to study the performance of our methods and a real meta-analysis provides further evidence. RESULTS: In our three simulation configurations, our diagnostic test for determining whether a meta-analysis is out of date had sensitivity of 55%, 62%, and 49% with corresponding specificity of 85%, 80%, and 90% respectively. CONCLUSIONS: Simulations suggest that our methods are able to detect out-of-date meta-analyses. These quick and approximate methods show promise for use by systematic review teams to help decide whether to commit the considerable resources required to update a meta-analysis. Further investigation and evaluation of the methods is required before they can be recommended for general use.

Computer Simulation↗

PubMed2003

Prolonged therapeutic hypothermia after traumatic brain injury in adults: a systematic review.

CONTEXT: The benefits of therapeutic hypothermia as a treatment for traumatic brain injury (TBI) remain unclear. OBJECTIVE: To explore the effects of depth, duration, and rate of rewarming after discontinuation of hypothermia on mortality and neurologic outcome in adults after TBI. DATA SOURCES: An electronic search of MEDLINE (OVID), EMBASE, Current Contents, the Cochrane library and a hand search of key journals were performed. Corresponding authors of identified studies were contacted for additional unpublished or ongoing clinical trials. STUDY SELECTION: All randomized controlled trials of therapeutic hypothermia for at least 24 hours vs normothermia in adults with TBI. DATA EXTRACTION: Demographic and clinical data, hypothermia interventions and cointerventions, mortality and neurologic outcomes, and methodological quality were abstracted by 2 independent reviewers. DATA SYNTHESIS: Twelve trials met eligibility criteria and were included in the analysis. We also performed subanalyses by different hypothermia interventions (ie, depth, duration, and rapidity of rewarming after hypothermia) and methodological quality. Therapeutic hypothermia was associated with a 19% reduction in the risk of death (95% confidence interval [CI], 0.69-0.96) and a 22% reduction in the risk of poor neurologic outcome (95% CI, 0.63-0.98) compared with normothermia. Hypothermia longer than 48 hours was associated with a reduction in the risks of death and of poor neurologic outcome (relative risk [RR], 0.70; 95% CI, 0.56-0.87 and RR, 0.65; 95% CI, 0.48-0.89, respectively) compared with normothermia. Hypothermia to a target temperature between 32 degrees C and 33 degrees C, a duration of 24 hours, and rewarming within 24 hours were all associated with reduced risks of poor neurologic outcome compared with normothermia. Assessment of methodological quality did not reveal evidence of bias. CONCLUSIONS: Therapeutic hypothermia may reduce the risks of mortality and poor neurologic outcome in adults with TBI. Outcomes were influenced, however, by depth and duration of hypothermia as well as rate of rewarming (<or=24 hours) after discontinuation of hypothermia. Nonetheless, the evidence is not yet sufficient to recommend routine use of therapeutic hypothermia for TBI outside of research settings.

Adult↗

PubMed2003

Randomized controlled trials in pediatric complementary and alternative medicine: where can they be found?

BACKGROUND: The safety and effectiveness of CAM interventions are of great relevance to pediatric health care providers. The objective of this study is to identify sources of reported randomized controlled trials (RCTs) in the field of pediatric complementary and alternative medicine (CAM). METHODS: Reports of RCTs were identified by searching Medline and 12 additional bibliographic databases and by reviewing the reference lists of previously identified pediatric CAM systematic reviews. RESULTS: We identified 908 reports of RCTs that included children under 18 and investigated a CAM therapy. Since 1965, there has been a steady growth in the number of these trials that are being published. The four journals that published the most reported RCTs are The American Journal of Clinical Nutrition, Pediatrics, Journal of Pediatrics, and Lancet. Medline, CAB Health, and Embase were the best database sources for identifying these studies; they indexed 93.2%, 58.4% and 42.2 % respectively of the journals publishing reports of pediatric CAM RCTs. CONCLUSIONS: Those working or interested in the field of pediatric CAM should routinely search Medline, CAB Health and Embase for literature in the field. The four core journals identified above should be included in their collection.

Authorship↗

PubMed2003

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

To comprehend the results of a randomised controlled trial (RCT), readers must understand its design, conduct, analysis, and interpretation. That goal can be achieved only through total 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 use of a checklist and flow diagram. The revised CONSORT statement presented here 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 this 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 four stages of a trial (enrollment, intervention allocation, follow- up, and analysis). The diagram explicitly shows 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 done 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↗

PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: The STARD Initiative.

BACKGROUND: To comprehend the results of diagnostic accuracy studies, readers must understand the design, conduct, analysis, and results of such studies. That goal can be achieved only through complete transparency from authors. OBJECTIVE: 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 the study and to evaluate its generalizability. 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, methodologists and statisticians, and members of professional organizations 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 on diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. The consensus meeting shortened the list to 25 items, using evidence on bias whenever available. A prototypical flow diagram provides information about the method of patient recruitment, 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 the clinicians, researchers, reviewers, journals, and the public.

Algorithms↗

PubMed2003

The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration.

The quality of reporting of studies of diagnostic accuracy is less than optimal. Complete and accurate reporting is necessary to enable readers to assess the potential for bias in the study and to evaluate the generalizability of the results. A group of scientists and editors has developed the STARD (Standards for Reporting of Diagnostic Accuracy) statement to improve the reporting the quality of reporting of studies of diagnostic accuracy. The statement consists of a checklist of 25 items and flow diagram that authors can use to ensure that all relevant information is present. This explanatory document aims to facilitate the use, understanding, and dissemination of the checklist. The document contains a clarification of the meaning, rationale, and optimal use of each item on the checklist, as well as a short summary of the available evidence on bias and applicability. The STARD statement, checklist, flowchart, and this explanation and elaboration document should be useful resources to improve reporting of diagnostic accuracy studies. Complete and informative reporting can only lead to better decisions in health care.

Algorithms↗

PubMed2003

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

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy, to allow readers to assess the potential for bias in a study, and to evaluate a study's generalisability. 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 two 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 patient recruitment, the order of test execution, and the numbers of patients undergoing the test under evaluation and the reference standard, or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the STARD checklist and 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↗

PubMed2003

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

OBJECTIVE: 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 the study and to evaluate its generalisability. 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 organizations shortened this list during a two-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 regarding 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 25 items, using evidence on bias whenever available. A prototypical flow diagram provides information about the method of patient recruitment, 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 the clinicians, researchers, reviewers, journals, and the public.

Algorithms↗

PubMed2003

Should meta-analysts search Embase in addition to Medline?

It is widely accepted that meta-analysts should search multiple databases. The selection of databases is ideally based on the potential contribution of each database to the project or on the potential for bias if a database is excluded, as supported by research evidence. We explore whether searching Embase yields additional trials that influence a meta-analysis. We identified meta-analyses that searched Medline and Embase. A random-effects weighted mean method was used to estimate the intervention effect in articles indexed only in Embase compared with those indexed elsewhere. On average, Embase-unique trials yielded significantly smaller estimates by 29% (ratio of odds ratio [ROR] 0.71, 95% confidence interval [CI] 0.56-0.90) but influenced the pooled estimate by an average of only 6% (ROR 0.94, 95% CI 0.88-0.99). Searching Medline but not Embase risks biasing a meta-analysis by finding studies that show larger estimates, but their prevalence seems low enough that the risk may be slight, provided the rest of the search is comprehensive.

Databases, Bibliographic↗

PubMed2003

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

RATIONALE AND OBJECTIVES: To comprehend the results of diagnostic accuracy studies, readers must understand the design, conduct, and analysis of such studies. The authors sought to develop guidelines for improving the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers better to assess the validity and generalizability of study results. MATERIALS AND METHODS: The Standards for Reporting of Diagnostic Accuracy group steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and to extract potential guidelines for authors and editors. An extensive list of items was prepared. Members of the steering committee then met for 2 days with other researchers, editors, methodologists, statisticians, and members of professional organizations to develop a checklist and a prototypical flowchart to guide authors and editors of studies of diagnostic accuracy. RESULTS: The search for published guidelines on diagnostic research yielded 33 previously published checklists, from which the group produced an initial list of 75 items. This list was honed to 25 key items by group consensus and on the basis of published research on bias. A prototypical flowchart was developed as a tool for conveying information about the method of patient recruitment, the order of test execution, and the numbers of patients undergoing the test under evaluation, the reference test, or both. Potential users reviewed the conference version of the checklist and flowchart and provided additional suggestions, which were then incorporated. CONCLUSION: Use of these carefully developed, consensus-based guidelines should enable clearer and more complete reporting of studies of diagnostic accuracy, as well as better reader understanding of the validity and generalizability of study results.

Bias↗

PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: The STARD Initiative.

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy, to allow readers to assess the potential for bias in the study and to evaluate its generalisability. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering group 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 two-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 regarding 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, using evidence, whenever available. A prototypical flow diagram provides information about the method of patient recruitment, 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 the clinicians, researchers, reviewers, journals, and the public.

Algorithms↗

PubMed2003

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

BACKGROUND: 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 generalizability 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 organizations 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 regarding 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 25 items, using evidence on bias whenever available. A prototypical flow diagram provides information about the method of patient recruitment, 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 the clinicians, researchers, reviewers, journals and the public.

Diagnostic Errors↗

PubMed2003

Toward complete and accurate reporting of studies of diagnostic accuracy. The STARD initiative.

Our objective was to improve the accuracy and completeness of reporting of studies of diagnostic accuracy, to allow readers to assess the potential for bias in the study, and to evaluate its generalizability. The Standards for Reporting of Diagnostic Accuracy 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 organizations 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. The search for published guidelines regarding 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, using evidence whenever available. A prototypical flow diagram provides information about the method of patient recruitment, the order of test execution, and the numbers of patients undergoing the test under evaluation, the reference standard, or both. 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↗

PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative. Standards for Reporting of Diagnostic Accuracy.

BACKGROUND: To comprehend the results of diagnostic accuracy studies, readers must understand the design, conduct, analysis, and results of such studies. That goal can be achieved only through complete transparency from authors. OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy to allow readers to assess the potential for bias in the study and to evaluate its generalisability. 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 two-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 on diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. The consensus meeting shortened the list to 25 items, using evidence on bias whenever available. A prototypical flow diagram provides information about the method of patient recruitment, 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↗

PubMed2003

The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration.

The quality of reporting of studies of diagnostic accuracy is less than optimal. Complete and accurate reporting is necessary to enable readers to assess the potential for bias in the study and to evaluate the generalisability of the results. A group of scientists and editors has developed the STARD (Standards for Reporting of Diagnostic Accuracy) statement to improve the reporting the quality of reporting of studies of diagnostic accuracy. The statement consists of a checklist of 25 items and flow diagram that authors can use to ensure that all relevant information is present. This explanatory document aims to facilitate the use, understanding and dissemination of the checklist. The document contains a clarification of the meaning, rationale and optimal use of each item on the checklist, as well as a short summary of the available evidence on bias and applicability. The STARD statement, checklist, flowchart and this explanation and elaboration document should be useful resources to improve reporting of diagnostic accuracy studies. Complete and informative reporting can only lead to better decisions in healthcare.

Algorithms↗