On level 1 we separated primary research studies and systematic reviews, and for both of these categories whether articles already reported data or were protocols.
Sensitivity and specificity are considered inappropriate for meta-analyses, as they do not behave independently when they are pooled from various primary studies to generate separate averages.[ 2] In our survey, separate pooling of sensitivities or specificity was used frequently in meta-analyses where summary ROC would have been more appropriate.
Nevertheless, the implementation of the study in four separate primary care settings allows for broader, comprehensive understanding with respect to issues of program effectiveness, applicability, feasibility and context.
The overall purpose of the synthesis was to 'pool' the results from individual primary studies by initially separating the findings, interpreting and then combining them through the identification of key themes across the studies [ 24].
Ancillary studies often involve the comparison of cohorts who experienced different treatment protocols in separate primary trials, or pooling of subsets of participants across different primary studies for use in new analyses.
A total of 33 relevant primary studies in relation to 27 separate interventions were included in this review.
A meta-analysis is an attempt to combine data from several separate primary data sources to increase the power for the study for the outcome variable.
A number of primary studies assessing the association between diabetes and separate geriatric outcomes had methodological flaws, such as a cross-sectional design [13], [21], [22], problematic diabetic ascertainment [23], [24], or inadequate consideration of potential confounders [25].
In addition, although the study is limited by small numbers, important trends are shown that suggest different metastatic pathways for mucosal melanoma arising from anatomically separate primary sites.
