Summary
Treats studies as inferential chains in which conclusions are only as strong as the weakest link, walking through seven sequential decisions from research question to interpretation and matching STROBE, CONSORT, and PRISMA reporting frameworks plus GRADE certainty ratings to different study families. Distinguishes reporting quality from methodological quality, showing that a flawed convenience-sample study can be fully STROBE-compliant. Lays out a five-stage stepwise appraisal procedure illustrated by the hormone-replacement-therapy reversal and adds pattern recognition for warning signs along with a procedure for synthesizing evidence when studies disagree.