had full access to all the data in the study and takes full responsibility for the integrity of the data and the accuracy of the data analysis.

PURPOSE Mobile devices provide individuals with rapid and frequent access to electronic patient portals. We investigated how oncology patients use this technology to review test results and communicate with providers. PATIENTS AND METHODS We performed a retrospective study of patients enrolled in the MyChart electronic health portal associated with the Epic electronic medical record at the Harold C. Simmons Comprehensive Cancer Center from 2012 to 2017. We recorded type of portal access according to year and patient characteristics. Associations among patient characteristics and types of portal access were tested using Mann-Whitney U test, χ2 test, and linear Gaussian regression models. RESULTS Since the availability of a mobile device application in 2012, 2,524 patients with cancer accessed MyChart from a mobile device at least once, which accounted for 291,526 mobile log-ins. The number of patients with MyChart mobile application log-ins increased from 4% in 2012 to 13% in 2017 ( P = .004). Among these patients, the median proportion of log-ins that occurred through mobile device use increased from 22% to 72% during this time period ( P < .001). Mobile access occurred more frequently among younger ( P < .001), black ( P = .002), and Hispanic ( P = .004) patients. Since 2012, total portal log-in frequency increased approximately 110% among patients who used the mobile application compared with 25% among those who did not use the mobile application ( P < .001). CONCLUSION Mobile access to electronic health portals has increased patient portal use, particularly among traditionally underserved populations. How this widely and immediately available technology affects patient expectations and experiences warrants additional study.

179 Background: Mobile devices provide individuals with rapid and frequent access to electronic patient portals. How patients use this growing and widespread technology to review test results and communicate with providers is not known. Methods: Retrospective study of patients enrolled in the MyChart electronic health portal associated with the EPIC electronic medical record in the Harold C. Simmons Comprehensive Cancer Center. We recorded type of portal access according to year and patient characteristics. Associations between patient characteristics and type of portal access were tested using Mann-Whitney test, Chi-square test, and linear Gaussian regression models. Results: Since the availability of mobile access in 2012, 2,524 patients accessed MyChart from a mobile device at least once, accounting for 291,526 mobile logins. The proportion of patients with mobile MyChart logins increased from 4% in 2012 to 13% in 2017 ( P= 0.004). Among these patients, the proportion of logins from mobile devices increased from 22% to 72% ( P< 0.001). Mobile access occurred more frequently among younger ( P< 0.001), black ( P= 0.002), and Hispanic ( P= 0.004) patients. In 2017, among patients who accessed MyChart from mobile devices at least once, those under age 40 years used the mobile application for over 90% of logins; those over age 60 years used the mobile application for 65% of logins. Black and Hispanic patients who used mobile MyChart access did so for approximately 80% of logins, compared to 70% of logins for non-Hispanic white patients. Before 2012, patients who went on to use mobile access averaged about five more logins per year than did mobile application never-users. While login frequency increased for both groups, the change was far greater for mobile application users. After 2012, total portal login frequency increased approximately 110% among patients who used mobile access, compared to 25% among non-users ( P< 0.001). Conclusions: Mobile access to electronic health portals has increased patient portal use, particularly among traditionally underserved populations. How this widely and immediately available technology impacts patient and practice experiences warrants further study.