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.