How effective is teaching critical appraisal skills to healthcare professionals? A systematic review of the literature

Article type
Authors
Taylor RS, Reeves B, Ewings P
Abstract
Objective: There is currently a worldwide interest in an evidence-based based approach to healthcare provision. In order to achieve this, individual healthcare professionals and managers are being trained in 'critical appraisal' skills ie the ability to assess the validity and applicability of published evidence and incorporate the results of this assessment into patient care. This paper describes a systematic review of studies undertaken to evaluate the impact of teaching critical appraisal skills to healthcare professionals.

Methods: An initial groups of studies, evaluating the effectiveness of various critical appraisal teaching strategies, was identified from a previously published review. Additional studies were identified by a literature search of MEDLINE and CINAHL databases searched for the period of 1966-1995. The bibliographies of the references obtained by these methods were also inspected. In addition, previous reviews, major textbooks on medical education and evidence-based healthcare were searched for references. Articles were included in the review if: (1) the purpose of the study was to assess the effectiveness of teaching critical appraisal skills, (2) the study included a comparison (control) group, and (3) objective measurement of study outcome(s) was undertaken and determination was made regarding the extent to which these indicated the study was positive (demonstrated a statistically significant improvement in outcome at the level of P<0.05), negative (showed no improvement or a decrement in outcome, despite sufficient statistical power to do so), or inconclusive (failed to demonstrate a change but lacked statistical power)

Results: Nine studies were identified which met the review's inclusion criteria. These studies included one randomised controlled trial, 2 non-randomised trials and the remainder used non-experimental designs. The outcomes assessed included knowledge of epidemiology/statistics, reading behaviour, appraisal skill level, and attitudes towards the use of evidence in practice. These studies reported a total of 17 outcomes, 8 (47%) of which demonstrated a positive result, in 3 (18%) a negative result, and in 6 cases (35%) an inconclusive result.

Discussion: In the main these results are supportive of the effectiveness of critical appraisal training in physicians and medical students. However, there a number of reasons for being cautious about generalising their findings: the methodological quality of the studies was variable, the assessment of outcome was often not blinded, the outcomes used were invariably not validated, and the studies were limited to the medical profession. There is an urgent need for methodologically well-conducted trials investigating the impact of teaching critical appraisal skills to a range of health care professionals.