Abstract
BackgroundMeta-analyses typically consider multiple outcomes and report univariate effect sizes considered as independent. Multivariate meta-analysis (MVMA) incorporates outcome correlation and synthesises direct evidence and related outcome estimates within a single analysis. In a series of meta-analyses from the critically ill literature, the current study contrasts multiple univariate effect estimates and their precision with those derived from MVMA.MethodsA previous meta-epidemiological study was used to identify meta-analyses with either one or two secondary outcomes providing sufficient detail to structure bivariate or tri-variate MVMA, with mortality as primary outcome. Analysis was performed using a random effects model for both odds ratio (OR) and risk ratio (RR); borrowing of strength (BoS) between multivariate outcome estimates was reported. Estimate comparisons, β coefficients, standard errors (SE) and confidence interval (CI) width, univariate versus multivariate, were performed using Lin’s concordance correlation coefficient (CCC).ResultsIn bivariate meta-analyses, for OR (n = 49) and RR (n = 48), there was substantial concordance (≥ 0.69) between estimates; but this was less so for tri-variate meta-analyses for both OR (n = 25; ≥ 0.38) and RR (≥ -0.10; n = 22). A variable change in the multivariate precision of primary mortality outcome estimates compared with univariate was present for both bivariate and tri-variate meta-analyses and for metrics. For second outcomes, precision tended to decrease and CI width increase for bivariate meta-analyses, but was variable in the tri-variate. For third outcomes, precision increased and CI width decreased. In bivariate meta-analyses, OR coefficient significance reversal, univariate versus MVMA, occurred once for mortality and 6 cases for second outcomes. RR coefficient significance reversal occurred in 4 cases; 2 were discordant with OR. For tri-variate OR meta-analyses reversal of coefficient estimate significance occurred in two cases for mortality, nine cases for second and 7 cases for third outcomes. In RR meta-analyses significance reversals occurred for mortality in 2 cases, 6 cases for second and 3 cases for third; there were 7 discordances with OR. BoS was greater in trivariate MVMAs compared with bivariate and for OR versus RR.ConclusionsMVMA would appear to be the preferred solution to multiple univariate analyses; parameter significance changes may occur. Analytic metric appears to be a determinant.
Highlights
Meta-analyses typically consider multiple outcomes and report univariate effect sizes considered as independent
*Correspondence: john.moran@adelaide.edu.au Department of Intensive Care Medicine, The Queen Elizabeth Hospital, Woodville, SA 5011, Australia. Such an approach has two attendant consequences; it ignores the effect of outcome correlation upon individual estimates, assuming that they are independent [1], and engenders multiplicity of the Type I error rate [2]. Confounding such effects is the selective reporting of outcomes, or outcome reporting bias (ORB), whereby secondary outcomes are selectively reported based upon outcome results [3, 4]
One problematic requirement of Multivariate meta-analysis (MVMA) is the provision of with-study correlations which are rarely reported, methods based upon individual patient [12] or aggregated data [13] and within the Bayesian framework [14] have been undertaken
Summary
Meta-analyses typically consider multiple outcomes and report univariate effect sizes considered as independent. Meta-analyses typically consider more than one outcome, and the conventional approach is to report multiple univariate effect size estimates of these separate outcomes. Such an approach has two attendant consequences; it ignores the effect of outcome correlation upon individual estimates, assuming that they are independent [1], and engenders multiplicity of the Type I error rate [2]. Confounding such effects is the selective reporting of outcomes, or outcome reporting bias (ORB), whereby secondary outcomes are selectively reported based upon outcome results [3, 4]. As results based upon indices of risk, odds ratio (OR) and risk ratio (RR), are not generally inter-translatable [16], both OR and RR estimates were compared
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
