P1-07-07: Assessing Two Methods of Meta-Analysis in Studies of Patients with Breast Cancer: Individual Patient Data-Based (IPD) Versus Literature Based Abstracted Data (AD) in 5 Meta-Analyses Including over 28,000 Patients. Are There Results Differences of Concern?

Author(s):  
RJ Gralla ◽  
E Bria ◽  
H Raftopoulos ◽  
I Sperduti ◽  
D Giannarelli ◽  
...  
2020 ◽  
Vol 80 ◽  
pp. 101883
Author(s):  
James Temple ◽  
Peter Salmon ◽  
Catrin Tudur Smith ◽  
Christopher D. Huntley ◽  
Angela Byrne ◽  
...  

2008 ◽  
Vol 24 (03) ◽  
pp. 358-361 ◽  
Author(s):  
Laura Koopman ◽  
Geert J. M. G. van der Heijden ◽  
Arno W. Hoes ◽  
Diederick E. Grobbee ◽  
Maroeska M. Rovers

Objectives:Individual patient data (IPD) meta-analyses have been proposed as a major improvement in meta-analytic methods to study subgroup effects. Subgroup effects of conventional and IPD meta-analyses using identical data have not been compared. Our objective is to compare such subgroup effects using the data of six trials (n= 1,643) on the effectiveness of antibiotics in children with acute otitis media (AOM).Methods:Effects (relative risks, risk differences [RD], and their confidence intervals [CI]) of antibiotics in subgroups of children with AOM resulting from (i) conventional meta-analysis using summary statistics derived from published data (CMA), (ii) two-stage approach to IPD meta-analysis using summary statistics derived from IPD (IPDMA-2), and (iii) one-stage approach to IPD meta-analysis where IPD is pooled into a single data set (IPDMA-1) were compared.Results:In the conventional meta-analysis, only two of the six studies were included, because only these reported on relevant subgroup effects. The conventional meta-analysis showed larger (age < 2 years) or smaller (age ≥ 2 years) subgroup effects and wider CIs than both IPD meta-analyses (age < 2 years: RDCMA-21 percent, RDIPDMA-1-16 percent, RDIPDMA-2-15 percent; age ≥2 years: RDCMA-5 percent, RDIPDMA-1-11 percent, RDIPDMA-2-11 percent). The most important reason for these discrepant results is that the two studies included in the conventional meta-analysis reported outcomes that were different both from each other and from the IPD meta-analyses.Conclusions:This empirical example shows that conventional meta-analyses do not allow proper subgroup analyses, whereas IPD meta-analyses produce more accurate subgroup effects. We also found no differences between the one- and two-stage meta-analytic approaches.


2021 ◽  
Vol 108 (Supplement_4) ◽  
Author(s):  
P Probst ◽  
U Klaiber ◽  
S Seide ◽  
M Kawai ◽  
I Matsumoto ◽  
...  

Abstract Objective Some studies have indicated that resecting the pylorus during partial pancreatoduodenectomy (PD) may lead to reduced delayed gastric emptying (DGE). Randomized controlled trials (RCTs) showed conflicting results regarding superiority of pylorus-resecting PD (prPD) compared to the pylorus-preserving procedure (ppPD). The aim of this individual patient data meta-analysis was to investigate risk factors on an individual patient level which may explain the observed differences between the existing RCTs. Methods RCTs comparing ppPD and prPD were searched systematically in MEDLINE, Web of Science and CENTRAL. Individual patient data (IPD) from existing RCTs were included. The primary endpoint was DGE according to the International Study Group of Pancreatic Surgery (ISGPS) adjusted for age, sex and body-mass-index (BMI). The meta-regression model was applied to the IPD of the RCTs. Mixed effects models were applied to perform meta-analyses. Results IPD from 418 patients (three RCTs) were used for quantitative synthesis. There was no significant statistical difference between ppPD and prPD regarding DGE adjusted for age, sex and BMI (OR 0.72; 95%-CI: 0.41 to 1.22) and DGE grade (RR 1.01; 95%-CI: 0.64 to 1.57). Regarding other relevant perioperative and postoperative outcome parameters, there were also no significant differences among the two techniques. Conclusion This IPD meta-analysis comparing preservation and resection of the pylorus during PD confirmed that the resection of the pylorus is not superior to the pylorus-preserving procedure regarding DGE. The pylorus should therefore be preserved whenever possible. Further RCT are futile, because their results are unlikely to change the pooled estimate for DGE.


Author(s):  
Janet L. Peacock ◽  
Sally M. Kerry ◽  
Raymond R. Balise

Chapter 13 introduces systematic reviews and meta-analyses, describing the use of aggregate or individual patient data. It describes how bias can arise in meta-analyses. It describes and demonstrates the use of the PRISMA guidelines statement.


2000 ◽  
Vol 16 (2) ◽  
pp. 657-667 ◽  
Author(s):  
Jayne F. Tierney ◽  
Mike Clarke ◽  
Lesley A. Stewart

Objective: There is increasing empirical evidence for the existence of bias in the publication of primary clinical research, with statistically significant results being published more readily, more quickly, and in higher impact journals. Meta-analysis of individual patient data (IPD) may represent a gold standard of “secondary” clinical research, giving the best possible summary of current evidence for a particular question, but publication of these may also be subject to bias. This study aimed to explore which factors might be associated with publication of IPD meta-analyses and to identify potential sources of bias.Methods: For all known IPD meta-analysis projects in cancer, the responsible investigator was surveyed by means of a questionnaire to determine descriptive characteristics of the meta-analysis, the nature of the results, and details of the publication history.Results: There is no good evidence that overall publication status of meta-analyses in cancer is dependent on the statistical or clinical significance of the results. However, those meta-analyses with nonsignificant results did seem to take longer to publish and were published in lower impact journals compared with those with more striking results.Conclusions: Based on the current data, there seems to be no strong association between the results of IPD meta-analyses in cancer and publication.


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