Journal ArticleDOI
An empirical study of the effect of the control rate as a predictor of treatment efficacy in meta-analysis of clinical trials.
TLDR
The significant correlation between the CR and the TE suggests that, rather than merely pooling the TE into a single summary estimate, investigators should search for the causes of heterogeneity related to patient characteristics and treatment protocols to determine when treatment is most beneficial and that they should plan to study this heterogeneity in clinical trials.Abstract:
If the control rate (CR) in a clinical trial represents the incidence or the baseline severity of illness in the study population, the size of treatment effects may tend to very with the size of control rates. To investigate this hypothesis, we examined 115 meta-analyses covering a wide range of medical applications for evidence of a linear relationship between the CR and three treatment effect (TE) measures: the risk difference (RD); the log relative risk (RR), and the log odds ratio (OR). We used a hierarchical model that estimates the true regression while accounting for the random error in the measurement of and the functional dependence between the observed TE and the CR. Using a two standard error rule of significance, we found the control rate was about two times more likely to be significantly related to the RD (31 per cent) than to the RR (13 per cent) or the OR (14 per cent). Correlations between TE and CR were more likely when the meta-analysis included 10 or more trials and if patient follow-up was less than six months and homogeneous. Use of weighted linear regression (WLR) of the observed TE on the observed CR instead of the hierarchical model underestimated standard errors and overestimated the number of significant results by a factor of two. The significant correlation between the CR and the TE suggests that, rather than merely pooling the TE into a single summary estimate, investigators should search for the causes of heterogeneity related to patient characteristics and treatment protocols to determine when treatment is most beneficial and that they should plan to study this heterogeneity in clinical trials.read more
Citations
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Journal ArticleDOI
The TIMI Risk Score for Unstable Angina/Non–ST Elevation MI: A Method for Prognostication and Therapeutic Decision Making
Elliott M. Antman,Marc Cohen,Peter J.L.M Bernink,Carolyn H. McCabe,Thomas Horacek,Gary Papuchis,Branco Mautner,Ramón Corbalán,David Radley,Eugene Braunwald +9 more
TL;DR: In patients with UA/NSTEMI, the TIMI risk score is a simple prognostication scheme that categorizes a patient's risk of death and ischemic events and provides a basis for therapeutic decision making.
Journal ArticleDOI
Publication and related bias in meta-analysis : power of statistical tests and prevalence in the literature
TL;DR: Tests for small-study effects should routinely be performed in meta-analysis, particularly for moderate amounts of bias or meta-analyses based on a small number of small studies.
Journal ArticleDOI
GRADE guidelines: 7. Rating the quality of evidence—inconsistency
Gordon H. Guyatt,Andrew D Oxman,Regina Kunz,James Woodcock,Jan Brozek,Mark Helfand,Pablo Alonso-Coello,Paul Glasziou,Roman Jaeschke,Elie A. Akl,Susan L Norris,Gunn Elisabeth Vist,Philipp Dahm,Vijay K Shukla,Julian P T Higgins,Yngve Falck-Ytter,Holger J. Schünemann +16 more
TL;DR: Credibility is increased if subgroup effects are based on a small number of a priori hypotheses with a specified direction; subgroup comparisons come from within rather than between studies; tests of interaction generate low P-values; and have a biological rationale.
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Microarray data analysis: from disarray to consolidation and consensus.
TL;DR: In just a few years, microarrays have gone from obscurity to being almost ubiquitous in biological research, and points of consensus are emerging about the general approaches that warrant use and elaboration.
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The case of the misleading funnel plot.
TL;DR: Evidence based medicine insists on rigorous standards to appraise clinical interventions, and failure to apply the same rules to its own tools could be equally damaging.
References
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Meta-Analysis in Clinical Trials*
TL;DR: This paper examines eight published reviews each reporting results from several related trials in order to evaluate the efficacy of a certain treatment for a specified medical condition and suggests a simple noniterative procedure for characterizing the distribution of treatment effects in a series of studies.
Journal ArticleDOI
Blood pressure, stroke, and coronary heart disease: Part 2, short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context
Rory Collins,Richard Peto,Stephen MacMahon,Patricia R. Hebert,N H Fiebach,Kimberley Eberlein,Jon Godwin,Nawab Qizilbash,James O. Taylor,Charles H. Hennekens +9 more
TL;DR: A sufficiently high risk of stroke (perhaps because of age, blood pressure, or, in particular, history of cerebrovascular disease) may be the clearest indication for antihypertensive treatment.
Journal ArticleDOI
Improving the quality of reporting of randomized controlled trials. The CONSORT statement.
Colin B. Begg,Mildred K. Cho,Susan Eastwood,Richard Horton,David Moher,Ingram Olkin,Roy M. Pitkin,Drummond Rennie,Kenneth F. Schulz,David L. Simel,Donna F. Stroup +10 more
TL;DR: For RCTs to ultimately benefit patients, the published report should be of the highest possible standard and should provide the reader with the ability to make informed judgments regarding the internal and external validity of the trial.
Journal Article
Chemotherapy in non-small cell lung cancer: A meta-analysis using updated data on individual patients from 52 randomised clinical trials
TL;DR: The results of this meta-analysis suggest that chemotherapy may have a role in treating non-small cell lung cancer, and reached conventional levels of significance when used with radical radiotherapy and with supportive care.
Journal ArticleDOI
Overview of randomized trials of angiotensin-converting enzyme inhibitors on mortality and morbidity in patients with heart failure
Rekha Garg,Salim Yusuf +1 more
TL;DR: Total mortality and hospitalization for congestive heart failure are significantly reduced by ACE inhibitors with consistent effects in a broad range of patients.