At their core systematic reviews aggregate evidence from primary studies, globally.
307 A recent systematic review, aggregating the results of several methodological investigations, found that, for subjective outcomes, trials that used inadequate or unclear allocation concealment yielded 31% larger estimates of effect than those that used adequate concealment, and trials that were not blinded yielded 25% larger estimates.
It is also unclear why a high proportion of guidelines utilised evidence from existing systematic reviews of aggregate data (or carried out their own analyses based on aggregate data) when relevant systematic reviews and meta-analyses of IPD were available, as was the case for each of the guidelines included in this study.
Apexification of immature teeth with calcium hydroxide or mineral trioxide aggregate: systematic review and meta-analysis.
The available systematic reviews of aggregate data are compromised because the primary studies report both adjusted and unadjusted estimates.
The primary source of bias in this case will be the systematic changes in aggregate facility-level characteristics, such as mean demographics and comorbidities, over time.
No widely agreed criteria exist for assessing the risk of bias in aggregate systematic reviews of prognostic studies [ 14] and there is a complete absence of established guidelines for prognostic IPD reviews (personal communication, D. Altman, R.Riley 2012).
These investigations comprise a review of individual case reports (including an independent evaluation by an external expert panel), quantitative analyses assessing potential associations, systematic reviews of aggregate safety data and a literature review.
Copies of the EMBASE and MEDLINE search strategies can be found in Additional file 2: Appendix 2. One reviewer will apply the IPD review eligibility criteria to the full-text articles of the studies identified in our literature search and also all studies excluded from our aggregate systematic review to ensure we do not miss eligible IPD.
We investigated the potential CRPS signal in relation to HPV-16/18-adjuvanted HPV-16/18-adjuvanted HPV-16/18-adjuvanted CRPS cases with independent expert confirmation; a disproportionality analysis and analyses of temporality; an observaccinesus expeCervarix®ysis using pubyishedatabaseound incidence review systematic reviews of aggregate safety data, and a literature review.
