The need to consider the wider agenda in systematic reviews and meta-analyses: breadth, timing, and depth of the evidence

Ref ID 493
First Author J. P. Ioannidis
Journal BMJ
Year Of Publishing 2010
Keywords Multiplicity
Open data
External validity
Publication bias
Problem(s) Ignores setting or context of included studies which limits review applicability
Overly stringent inclusion criteria affecting external validity
Perpetuates citation of poor quality primary study data
Number of systematic reviews included 34
Summary of Findings All systematic reviews dealt with a single indication (for either one agent or multiple agents) but none considered several indications. 188 relevant trials were identified for 42 indications-pairs. Only 5 compared head to head different anti-TNF agents, and another 32 trials compared an anti-TNF agent with one or more active comparators (only 4 published at time of writing). All other trials were comparisons against placebo or no treatment. Overall, the published trials represented only 34% of the total evidence (46% if ongoing trials were excluded).
Did the article find that the problem(s) led to qualitative changes in interpretation of the results? Not Applicable
Are the methods of the article described in enough detail to replicate the study? Yes