Association of Mobile Patient Portal Access With Diabetes Medication Adherence and Glycemic Levels Among Adults With Diabetes

This cohort study examines the association of increased patient portal access with medication adherence and glycemic control among patients with diabetes. Question Is mobile access to a patient portal associated with improved outcomes for patients with diabetes? Findings In this cohort study of 111463 patients with diabetes serving as their own controls, gaining mobile portal access was associated with significantly higher adherence to oral diabetes medications and lower glycemic levels. These improvements were substantially larger among patients with higher baseline glycemic levels. Meaning These findings suggest that convenient access to portal self-management tools through a mobile device could significantly improve diabetes care. Importance Online patient portals support self-management, and mobile devices expand portal access, but whether this translates to improvements in diabetes outcomes is unclear. Objective To examine the association of adding mobile patient portal access with diabetes medication adherence and glycemic levels among adults with diabetes. Design, Setting, and Participants This retrospective cohort study included patients with diabetes treated at Kaiser Permanente Northern California, a large, integrated health care delivery system, from April 1, 2015, to December 31, 2017. Inclusion criteria were adults with diabetes with an oral diabetes prescription at baseline and no insulin use. Data were analyzed from March 2018 to March 2019. Exposures Patient portal access status for each calendar month from April 2015 to December 2017, categorized as never used, used from a computer only, used from a mobile device only, or used from both computer and mobile device. Main Outcomes and Measures Medication adherence, measured by monthly percentage of days covered (PDC), and glycemic levels, measured by changes in glycated hemoglobin A(1c) (HbA(1c)) levels. The association of portal access with study outcomes was assessed using linear regression with patient-level fixed effects and adjusting for time-changing variables, stratified by baseline HbA(1c) level. Results Among 111463 included patients (mean [SD] age, 63.79 [12.93] years; 59918 [53.76%] men), the number of patients using the portal from both a computer and mobile device increased over time from 38371 patients (34.42%) in April 2015 to 57920 patients (61.71%) in December 2017. Among patients with no prior portal access, adding computer-only portal access was associated with an increase in PDC of 1.16 (95% CI, 0.63 to 1.70) percentage points and a change of -0.06 (95% CI, -0.08 to -0.03) percentage points in HbA(1c) level, and adding both mobile and computer portal access was associated with an increase in PDC of 1.67 (95% CI, 1.10 to 2.23) percentage points and a change of -0.13 (95% CI, -0.16 to -0.10) percentage points in HbA(1c) level. Among patients with higher baseline HbA(1c) level (>8.0%), changing from no portal access to both computer and mobile access was associated with an increase in PDC of 5.09 (95% CI, 3.78 to 6.40) percentage points and a change of -0.19 (95% CI, -0.27 to -0.15) percentage points in HbA(1c) level. Conclusions and Relevance These findings suggest that providing patients with computer patient portal access and combining it with mobile patient portal access are associated with significantly improved diabetes medication adherence and glycemic control, with greater benefits among patients with more clinical need. Convenient access to portal self-management tools through a mobile device could significantly improve diabetes management.