Abstract
Meta-analysis can be a powerful tool for demonstrating the
applicability of a concept beyond the context of individual clinical
trials and observational studies, including exploration of effects
across different subgroups. Meta-analysis avoids Simpsona??s paradox,
in which a consistent effect in constituent trials is reversed
when results are simply pooled. Meta-analysis in critical care
medicine is made more complicated, however, by the heterogeneous
nature of critically ill patients and the contexts within
which they are treated. Failure to properly adjust for this
heterogeneity risks missing important subgroup effects in, for
example, the interaction of treatment with varying levels of baseline
risk. When subgroups are defined by characteristics that vary
within constituent trials (such as age) rather than features constant
within each trial (such as drug dose), there is the additional risk of
incorrect conclusions due to the ecological fallacy. The present
review explains these problems and the strategies by which they
are overcome.
Original language | English |
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Pages (from-to) | 1 - 8 |
Number of pages | 8 |
Journal | Critical Care |
Volume | 12 |
Issue number | 220 |
DOIs | |
Publication status | Published - 2008 |