Abstract: We included two RCTs and four CRCTs involving 352 physicians, 48 residents, and 135 allied health practitioners. Overall risk of bias was low as was quality of the evidence. One comparison was supported by three studies and three comparisons were supported by single studies, but outcomes across the three studies were highly heterogeneous. We found no studies to support EHI versus no alternative. Given these factors, it was not possible to determine the relative effectiveness of interventions. All studies reported practitioner use of EHI, two reported on compliance with electronic practice guidelines, and none reported on patient outcomes. One trial (139 participants) measured guideline adherence for an electronic versus printed guideline, but reported no difference between groups (median OR 0.85, IQR 0.74 to 1.08). One small cross-over trial (10 participants) reported increased use of clinical guidelines when provided with a mobile versus stationary, desktop computer (mean use per shift: intervention group (IG) 3.6, standard deviation (SD) 1.7 vs. control group (CG) 2.0 (SD 1.9), P value = 0.033). One cross-over trial (203 participants) reported that using a customized versus a generic interface had little impact on practitioners' use of EHI (mean difference in adjusted end-of-study rate: 0.77 logins/month/user, 95% confidence interval (CI) CI 0.43 to 1.11). Three trials included education or training and reported increased use of EHI by practitioners following training. This review provided no evidence that the use of EHI translates into improved clinical practice or patient outcomes, though it does suggest that when practitioners are provided with EHI and education or training, the use of EHI increases. We have defined use as the activity of logging into an EHI resource, but based on our findings use does not automatically translate to the application of EHI in practice. While using EHI may be an important component of evidence-based medicine, alone it is insufficient to improve patient care or clinical practices. For EHI to be applied in patient care, it will be necessary to understand why practitioners' are reluctant to apply EHI when treating people, and to determine the most effective way(s) to reduce this reluctance.

Plain-language summary: We found six studies involving 535 healthcare practitioners. The studies examined strategies encouraging practitioners to use EHI when caring for patients. We measured practitioners' use of EHI by counting the number of times they logged onto it; by measuring whether or not practitioners' followed the guidance provided by EHI; and by improvements experienced by patients. The studies compared the following strategies: EHI versus printed information (one study); EHI on a "mobile" (e.g. laptop computer) versus a stationary, desktop computer (one study); EHI presented with different search interfaces (an interface is what a user sees when accessing an online resource, think of Google versus Yahoo) (one study); and EHI provided with training (three studies). The results of this review showed that when provided with a combination of EHI and training, practitioners used the information more often. Two studies measured doctors' use of electronic treatment guidelines, but showed that the electronic aspect of the guidelines did not mean that doctors followed the guidelines. This review provided no information on whether more frequent use of EHI translated into improved clinical practice or whether patients were better off when doctors or nurses used health information when treating them. All included studies were randomized controlled trials (clinical studies where people are randomly put into one of two or more treatment groups), which are considered high-quality sources of evidence. However, three of the four comparisons that we examined were supported by only one study each and single studies do not typically produce high-quality evidence. Overall, we rate the body of evidence in this review as low quality.