>>11766105look at the date of the study if it is very old there is a good chance that updated studies have been written in response to the old one.
sometimes the newer study will cite the old one and discuss the findings of the past evaluating how accurate it was.
also look for meta analysis studies
"Meta-analysis is a quantitative, formal, epidemiological study design used to systematically assess the results of previous research to derive conclusions about that body of research. Typically, but not necessarily, the study is based on randomized, controlled clinical trials."
