The researchers looked specifically at racial and ethnic minorities and found that while these groups had poorer medication adherence than white patients before using the online refills, using the online refills conferred the same benefit for every group.
"Many other systems are implementing online portals other than Kaiser," said lead author Dr. Courtney Lyles in a phone interview. "The key message that our study puts forward is that providing tools to help with medication adherence is critical."
Lyles, an affiliate investigator at the Kaiser Permanente Division of Research and assistant professor at the University of California, San Francisco, and her colleagues studied patients in the type 2 diabetes registry in Kaiser Permanente Northern California between 2006 and 2012.
All had access to online patient tools that allow for viewing medical history and visit summaries, viewing laboratory results, scheduling appointments, sending and receiving secure email messages with providers, and requesting prescription refills.
Patients could request a prescription refill online and receive the medication by mail or pick it up in person at the pharmacy.
The researchers compared diabetes patients with statin prescriptions who used the online refill tool to those who did not, and compared individual patients before and after they started using the online refills.
According to pharmacy data, at baseline, whites on average spent about 12% of the time without having the medicine on hand, compared to about 16% of the time for blacks and Latinos, and about 13% of the time for Asians and Filipinos.
But when patients switched from other refill habits to exclusively online refills, they reduced their time without statins by more than 3%, the researchers reported in an article online September 2 in the Journal of the American Medical Informatics Association.
Racial and ethnic minority patients are less likely to use online portals, even after adjusting for Internet access or use of Internet in everyday life, Lyles said.
"There is a concern that if particular populations are less likely to use these portals, then perhaps the benefits will be differential," she said. "But we found that racial minorities are less likely to use it overall, but have the same benefit in adherence."
Online portals do appear to make prescription refills more convenient, and people using the portals reduced the number of days without medication by 10 or 15 days per year, according to Dr. Jessica S. Ancker, a health care policy researcher at Weill Cornell Medical College in New York City, who was not part of the new study.
Healthcare organizations started offering online portals as a "leap of faith," assuming they would improve patient experiences, but without any concrete proof, she said.
"A new wave of research measures whether it's improving things," she said.
The Agency for Healthcare Research and Quality funded this research.