BACKGROUND:Clinical pathways are structured multidisciplinary care plans used by health services to detail essential steps in the care of patients with a specific clinical problem. They aim to link evidence to practice and optimise clinical outcomes whilst maximising clinical efficiency. OBJECTIVES:To assess the effect of clinical pathways on professional practice, patient outcomes, length of stay and hospital costs. SEARCH STRATEGY:We searched the Database of Abstracts of Reviews of Effectiveness (DARE), the Effective Practice and Organisation of Care (EPOC) Register, the Cochrane Central Register of Controlled Trials (CENTRAL) and bibliographic databases including MEDLINE, EMBASE, CINAHL, NHS EED and Global Health. We also searched the reference lists of relevant articles and contacted relevant professional organisations. SELECTION CRITERIA:Randomised controlled trials, controlled clinical trials, controlled before and after studies and interrupted time series studies comparing stand alone clinical pathways with usual care as well as clinical pathways as part of a multifaceted intervention with usual care. DATA COLLECTION AND ANALYSIS:Two review authors independently screened all titles to assess eligibility and methodological quality. Studies were grouped into those comparing clinical pathways with usual care and those comparing clinical pathways as part of a multifaceted intervention with usual care. MAIN RESULTS:Twenty-seven studies involving 11,398 participants met the eligibility and study quality criteria for inclusion. Twenty studies compared stand alone clinical pathways with usual care. These studies indicated a reduction in in-hospital complications (odds ratio (OR) 0.58; 95% confidence interval (CI) 0.36 to 0.94) and improved documentation (OR 13.65: 95%CI 5.38 to 34.64). There was no evidence of differences in readmission to hospital or in-hospital mortality. Length of stay was the most commonly employed outcome measure with most studies reporting significant reductions. A decrease in hospital costs/ charges was also observed, ranging from WMD +261 US$ favouring usual care to WMD -4919 US$ favouring clinical pathways (in US$ dollar standardized to the year 2000). Considerable heterogeneity prevented meta-analysis of length of stay and hospital cost results. An assessment of whether lower hospital costs contributed to cost shifting to another health sector was not undertaken.Seven studies compared clinical pathways as part of a multifaceted intervention with usual care. No evidence of differences were found between intervention and control groups. AUTHORS' CONCLUSIONS:Clinical pathways are associated with reduced in-hospital complications and improved documentation without negatively impacting on length of stay and hospital costs.