Effects of evidence-based clinical practice guidelines on quality of care: a systematic review

Background: Evidence-based clinical guidelines aim to improve the quality of care. In The Netherlands, considerable time and effort have been invested in the development and implementation of evidence-based guidelines since the 1990s. Thus far, no reviews are available on their effectiveness. The primary aim of this article was to assess the evidence for the effectiveness of Dutch evidence-based clinical guidelines in improving the quality of care. Methods: A systematic review of studies evaluating the effects of Dutch evidence-based guidelines on both the process and structure of care and patient outcomes was conducted. The electronic databases Medline and Embase (1990-2007) and relevant scientific journals were searched. Studies were only selected if they included a controlled trial, an interrupted time series design or a before and after design. Results: A total of 20 studies were included. In 17 of 19 studies that measured the effects on the process or structure of care, significant improvements were reported. Thirteen of these studies reported improvement with respect to some of the recommendations studied. In addition, the size of the observed effects varied largely across the recommendations within guidelines. Six of nine studies that measured patient health outcomes showed significant but small improvements as a result of the use of clinical guidelines. Conclusions: This review demonstrates that Dutch evidence-based clinical guidelines can be effective in improving the process and structure of care. The effects of guidelines on patient health outcomes were studied far less and data are less convincing. The high level of variation in effects across recommendations suggests that implementation strategies tailored to individual recommendations within the guideline are needed to establish relevant improvements in healthcare. Moreover, the results highlight the need for well-designed studies focusing on the level of the recommendations to determine which factors influence guideline utilisation and improved patient outcomes.