DEERFIELD, Ill — Reminder calls from pharmacists prove effective in getting late-to-refill seniors back on their medication regimen, according to a Walgreens study.

Medicare Part D patients who were late to refill prescriptions and received reminder calls from local Walgreens pharmacists showed almost 23% greater adherence within the first 14 days of the expected refill date, Walgreens said Wednesday.

Those receiving late-to-refill reminder calls also exhibited higher adherence rates over a one-year period, according to the study, titled “Impact of Late-to-Refill Reminder Calls on Medication Adherence in the Medicare Part D Population” and published online in Patient Preference & Adherence.

The randomized control study involved more than 735,000 patients who exhibited nonadherent behavior, defined as not refilling at least three days before an expected refill date. Patients were assigned to an intervention group and a control group, using Walgreens pharmaceutical claims data from 2015 to estimate the impact of late-to-refill calls by pharmacists on short-term and annual adherence.

For Part D patients showing nonadherent behavior, a late-to-refill reminder call raise the number of adherent patients by about 3%. That improvement in patient medication adherence can benefit Part D plans and help improve Star Ratings and related cost savings, according to the study.

“Improving medication adherence is critical to controlling most medical conditions. And for many medical conditions, enhancing adherence can also reduce hospitalizations and related medical costs,” Walgreens chief medical officer Harry Leider said in a statement. “This research provides further evidence of the positive impact we can have through targeted initiatives, such as the late-to-refill program, to help make our patients healthier and happier.”

About 32% of Part D patients are noncompliant with their diabetes, hypertension and cholesterol medications, the study said.

“Patient forgetfulness and misconceptions about the risk of side effects are potential drivers of nonadherence in this population,” the Walgreens researchers stated. “Local pharmacists can nudge patients to increase adherence, since they can remind them to refill medications on time and address their concerns about their medications.”