Re: Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies
In my opinion, the author's search strategy in this meta-analysis is very poor. Why, after countless studies demonstrating the presence of publication bias, have the authors only searched Pubmed and Embase? Is there a lack of unpublished data?
A meta-analysis by Hopewell et al (2007) showed that, on average, published studies show a 9% greater effect than unpublished studies. Thus, if authors, such as Liu et al, choose to ignore unpublished data, it should be well documented why. Ignoring the issue altogether leads to readers, such as myself, questioning the reported findings.
Competing interests: No competing interests