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Use of the Refill Function Through an Online Patient Portal is Associated With Improved Adherence to Statins in an Integrated Health System

Sarkar, Urmimala, MD, MPH*,†; Lyles, Courtney R., PhD*,†; Parker, Melissa M., MS; Allen, Jill, PhD§; Nguyen, Robert, MA§; Moffet, Howard H., MPH; Schillinger, Dean, MD*,†; Karter, Andrew J., PhD‡,∥

doi: 10.1097/MLR.0000000000000069
Original Articles

Background: Online patient portals are being widely implemented, but their impact on health behaviors are not well-studied.

Objective: To determine whether statin adherence improved after initiating use of the portal refill function.

Research Design: Observational cohort study within an integrated health care delivery system.

Subjects: Diabetic patients on statins who had registered for online portal access by 2010. A total of 8705 subjects initiated the online refill function use within the study window, including “exclusive” and “occasional” users (ie, requesting all vs. some refills online, respectively). Using risk-set sampling, we temporally matched 9055 reference group patients who never used online refills.

Measures: We calculated statin adherence before and after refill function initiation, assessed as percent time without medications (nonadherence defined as a gap of >20%). Secondary outcome was dyslipidemia [low-density lipoprotein (LDL)≥100]. Difference-in-differences regression models estimated pre-post changes in nonadherence and dyslipidemia, comparing refill function users to the reference group and adjusting for age, sex, race/ethnicity, medications, frequency of portal use, and outpatient visits.

Results: In unadjusted examinations, nonadherence decreased only among patients initiating occasional or exclusive use of the refill function (26%–24% and 22%–15%, respectively). In adjusted models, nonadherence declined by an absolute 6% (95% confidence interval, 4%–7%) among exclusive users, without significant changes among occasional users. Similar LDL decreases were also seen among exclusive users.

Conclusions: Compared with portal users who did not refill medications online, adherence to statin medications and LDL levels improved among diabetic patients who initiated and exclusively used the patient portal for refills, suggesting that wider adoption of online refills may improve adherence.

*Center for Vulnerable Populations

Department of Medicine, Division of General Internal Medicine, San Francisco General Hospital, University of California-San Francisco, San Francisco, CA

Division of Research, Kaiser Permanente Northern California

§Kaiser Foundation Health Plan, Internet Services Group, Oakland, CA

School of Public Health & Community Health, University of Washington, Seattle, WA

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

Supported by the National Institutes of Health (R01-DK080726, R01-DK081796). A.J.K., D.S., and H.H.M. are supported by the NIDDK Health Delivery Systems—Center for Diabetes Translational Research (HDS-CDTR) (P30 DK092924). U.S. is supported by the Agency for Health Care Research and Quality (K08HS017594). All listed authors meet each of the 3 authorship requirements as stated in the Uniform Requirements for Manuscripts Submitted to Biomedical Journals.

The authors declare no conflict of interest.

Reprints: Urmimala Sarkar, MD, MPH, Department of Medicine, Division of General Internal Medicine, University of California-San Francisco, Box 1364, 1001 Potrero, Bldg 10, 3rd Floor, San Francisco, CA 94143-1364. E-mail:

© 2014 by Lippincott Williams & Wilkins.