Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet #Preprint #PeerReviewMe: Warning: This is a unreviewed preprint. Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn. Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period. Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author). Background: eHealth tools are becoming increasingly popular for helping patients self-manage chronic conditions. Little research has examined the effect of ehealth tools for patient self-reporting on medication management. This review aims to determine whether ehealth tools featuring patient self-reporting of symptoms, adverse effects and drug therapy problems are effective at prompting medication changes and improving patient outcomes. Objective: The primary objective is to determine how patient self-reporting of symptoms and adverse effects via ehealth tools influences medication use and changes made to medications. Secondary objectives are to investigate how patient use of ehealth tools influences identification of adverse events, patient self-management of disease and self-efficacy, medication use behaviour, medication reconciliation and recommendations for drug changes, changes in patient signs and symptoms, health services utilization, quality of life, and patient satisfaction with health care. Methods: MEDLINE, EMBASE and CINAHL were searched from Jan 1, 2000 through to January 4, 2016. References were also searched. Title, abstract and full text review, as well as data abstraction and risk of bias assessment were performed in duplicate. Due to high heterogeneity, results were not meta-analyzed, and instead presented as a narrative synthesis. Results: 13 studies, including 10 randomized controlled trials (RCTs) and 3 single-arm cohort studies were included, from which 10 unique ehealth tools were identified. Here six of seven RCTs found improvement in patient symptoms following ehealth tool use, especially in adolescent asthma patients. Four of six RCTs reported that ehealth tools may have potential to initiate changes to medications based on patient self-reports. Two of four RCTs showed that ehealth tools may improve patient self-efficacy and self-management of chronic disease. Little or no evidence was found to support the effectiveness of ehealth tools at improving medication recommendations and reconciliation by clinicians, medication-use behaviour, health service utilization, quality of life, or patient satisfaction. eHealth tools with multifaceted functionalities and those allowing direct patient-provider communication may be more effective at improving patient self-management and self-efficacy. Conclusions: Initial evidence showing ehealth tools may improve patient symptoms and lead to medication changes is promising. Patients generally found ehealth tools useful in improving communication with health care providers. Implementation issues such as poor patient engagement and poor clinician workflow integration were identified. More high-quality research is needed to explore how ehealth tools can be used to effectively manage use of medications to improve patient outcomes.