Can a Patient Portal Improve Adherence to Medications?

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A patient portal is an online application which gives patients access to personal health information stored in a health care organization’s electronic health record (EHR). Patients use the portal to view information such as their lab results, medication lists, immunization records, and allergies. Some patient portals also allow users to request prescription refills (among other functions). Giving patients a convenient way of requesting refills should make it easier for them to keep up with refills, avoid lapses in the medication regimen, and achieve better disease control.

A research study with more than 17,000 patients was conducted to confirm whether that assertion was true. The study investigated whether patients who used the patient portal to request medication refills actually took their prescribed cholesterol medications (statins) more consistently than those who didn’t use the portal for refills. The investigators also compared levels of LDL cholesterol. The study involved adults with diabetes because cholesterol control is important in diabetes. All patients were members of the Kaiser Permanente Northern California health care system.

Patients were prescribed statins and had used at least one of the portal functions before they were entered into the study. They were further categorized into three groups. Non-users were those who never used the online refill function of the portal. Non-users requested their medication refills in-person or by telephone.

Patients in the second group were “occasional users”, i.e. those that requested statin refills via the online portal at least once but also used other means. The third group was comprised of “exclusive users” who requested all of their statin refills via the portal.

Medication adherence means that the patient takes it consistently and therefore requests the next refill before or very soon after the current medication supply runs out.

In other words, there is no medication gap. A patient who doesn’t take the medication consistently (nonadherence) requests the next refill later than expected. For example, if the first prescription was for 100 days, then a patient who requests the next refill 140 days after the first prescription started was not taking the medication consistently, and had a medication gap of 40 days (or 40% of 100). The main outcome of this study was nonadherence to statins, defined as having a medication gap greater than 20% of the study period.

Statin nonadherence did not change among portal non-users. In contrast, nonadherence decreased from 26% to 24% among occasional users and from 22% to 15% among exclusive users. The authors used statistical models (described below) to estimate that the prevalence of nonadherence decreased by 6% among exclusive users, after accounting for expected changes in adherence based on the non-user group. These models found no significant differences between occasional users of the online refill function and non-users.

There were similar improvements in LDL levels when comparing exclusive users to non-users.

There are limitations in the conclusions which can be drawn from this observational study. It is possible that patients who use portals have inherent characteristics that make it more likely that they would refill the statins. For example, portal users might believe in the benefits of statins more strongly than those who don’t use the portal. In that case, the portal itself may not have had any significant influence on adherence to the statins. These types of biases cannot be completely eliminated. However, the authors used standard statistical models to minimize the effect of these biases on their results. The models accounted for the patients’ previous tendency to be adherent to statins before the study, demographic characteristics (e.g. age, gender, race/ethnicity), and clinical characteristics.

In summary, this study found that compared to portal users who did not request statin refills online, patients who used the online portal for all their statin refill requests were more adherent to the medications and had better LDL levels. While it doesn’t prove that the portal itself was responsible for these improvements, it suggests that patient portals may boost medication adherence.


Urmimala S et al. Use of the Refill Function Through an Online Patient Portal is Associated With Improved Adherence to Statins in an Integrated Health System. Medical Care 2014; 52(3): 194–201.

Office of the National Coordinator for Health Information Technology. What is a patient portal. Accessed on July 29, 2014.

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