2 Systematic reviews apply scientific strategies in ways that limit bias to the assembly, a critical appraisal, and synthesis of relevant studies that address a specific clinical question. Narrative reviews, although still very common in the medical field, have been criticised because of the high risk of bias, and “systematic reviews” are preferred. Review articles in the medical literature have traditionally been in the form of “narrative reviews” where experts in a particular field provide what is supposed to be a “summary of evidence” in that field. Health care professionals have always used review articles as a source of summarised evidence on a particular topic. It is therefore important that health care decisions are not based solely on one or two studies without account being taken of the whole range of research information available on that topic. The quality of the studies may be variable, and the individual studies might have produced conflicting results. 1 After a literature search on a specific clinical question, many articles may be retrieved. In the first article of the series, I described basic strategies that could be used to search the medical literature. Health care professionals are increasingly required to base their practice on the best available evidence.

Comprehensive meta analysis for mac