Mentoring, as a partnership in personal and professional growth and development, is central to academic medicine, but it is challenged by increased clinical, administrative, research, and other educational demands on medical faculty. Therefore, evidence for the value of mentoring needs to be evaluated. To systematically review the evidence about the prevalence of mentorship and its relationship to career development. MEDLINE, Current Contents, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, PsycINFO, and Scopus databases from the earliest available date to May 2006. We identified all studies evaluating the effect of mentoring on career choices and academic advancement among medical students and physicians. Minimum inclusion criteria were a description of the study population and availability of extractable data. No restrictions were placed on study methods or language. The literature search identified 3640 citations. Review of abstracts led to retrieval of 142 full-text articles for assessment; 42 articles describing 39 studies were selected for review. Of these, 34 (87%) were cross-sectional self-report surveys with small sample size and response rates ranging from 5% to 99%. One case-control study nested in a survey used a comparison group that had not received mentoring, and 1 cohort study had a small sample size and a large loss to follow-up. Less than 50% of medical students and in some fields less than 20% of faculty members had a mentor. Women perceived that they had more difficulty finding mentors than their colleagues who are men. Mentorship was reported to have an important influence on personal development, career guidance, career choice, and research productivity, including publication and grant success. Mentoring is perceived as an important part of academic medicine, but the evidence to support this perception is not strong. Practical recommendations on mentoring in medicine that are evidence-based will require studies using more rigorous methods, addressing contextual issues, and using cross-disciplinary approaches.
