We extracted measures of associations that were the most adjusted for sociodemographic and lifestyle factors, with and without further adjustment for adiposity measures.
The overall risk of bias was low, as all studies were prospective cohort studies and most adjusted for many confounders.
Most studies were longitudinal cohort designs, allowing for stronger conclusions to be drawn regarding the predictive utility of the constructs under review and most adjusted for pre-pregnancy BMI, a known confounder of GWG [ 1].
Some studies adjusted the ORs to allow for confounders, and where possible, the most adjusted data have been reported.
The validity of use of "most adjusted" models, which account both for potential confounders and causal intermediates, has been debated.
When studies reported relative risks with different degrees of statistical adjustment for confounding, we used the most adjusted estimate.
The estimates are again little affected by preferring least, rather than most, adjusted RRs, with the estimates now 3.41 (3.00-3.87) for COPD, 3.43 (3.12-3.77) for CB and 4.32 (2.40-7.78) for emphysema.
Using the most adjusted data, however, the risks of saturated fat were largely gone.
We also abstracted the variables that each study used in its most adjusted analysis.
Alternatively, using RRs selected as most adjusted for other aspects of smoking, the overall estimate was 1.34 (1.16-1.56, n = 14).
