Often, meta-analyses are conducted after a collection of studies have been identified; statistical pooling occurs at one point in time.
Given the very large heterogeneity that may be encountered in observational studies, often meta-analysis may not be done in systematic reviews of observational studies, whereas this problem occurs much less frequently in systematic reviews of randomised controlled trials, for which meta-analysis is the norm, especially when interventions are drugs or vitamins.
Her take on the strip is often hilarious and frequently meta — exactly the sort of stuff we'd hope for Nancy and Sluggo.
Sensitive to the distance between filmmaker and subject, and between viewer and subject, anti-biopics are often, implicitly, meta-biopics, in much the same way that Janet Malcolm's book on Sylvia Plath and Ted Hughes, "The Silent Woman," turned a nominal biography into a meditation on the limits and the philosophical problems of biography.
Researchers often use meta-analyses to identify evidence-based practices.
This simple example of a recently published and often quoted meta-analysis shows that summary effect sizes and associated confidence intervals may be highly misleading when primary data suffer from fundamental problems such as restricted range due to ceiling or floor effects.
An often cited meta-analysis by Schaumberg et al. from 1998 reported pooled estimates of the proportion of eyes developing visually significant PCO of 11.8% (at 1 year postoperatively), 20.7% (at 3 years) and 28.4% (at 5 years) [ 13].
In one study, starting doses for r-hFSH varied between 150 and 300 IU. 3 In other reviews, gonadotropin dosage was highly heterogeneous and often not meta-analyzed, due to the marked heterogeneity between the data from individual trials.
The main strategy so far to address the problem is to continue to use commercially available microarrays, which only assess common variants, but to increase sample sizes, often through meta-analyses of results from several studies, in order to detect smaller effects.
"Meta" often means the thing is talking about itself.
It is intriguing that the gene expression levels are significantly distinct between meta-groups (Dunn's Method, p<0.001), but are often insignificant within meta-groups (data not shown), implying the partition of modules is reasonable.
