free full text: Reporting of eligibility criteria of randomised trials: cohort study comparing trial protocols with subsequent articles -- Blümle et al. 342 -- bmj.com

Conclusions:
Many users of trial information rely on published journal articles. These articles generally do not reflect the exact definition of the study population as prespecified in the protocol. Incomplete or inadequate reporting of eligibility criteria hampers a proper assessment of the applicability of trial results.