Blog Post

Chart of the Day: Longer Prescriptions Could Equalize All Patients’ Medication Supply

A Simple Change to Clinicians’ Prescribing System Reduced Prescription Disparities by Race, Ethnicity, Insurance Type, and Income

May 21, 2025

By:

Chris Tachibana, PhD, MS

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**Figure 1.** Within weeks of setting the default statin prescription length to 90 days across a primary care system, the percentage of all patients with a 90-day prescription increased from 71% to 92%. No change occurred for the control, nonstatin medication (levothyroxine, for hypothyroidism). Source: Authors’ analysis of the Penn Medicine electronic health record

Increasing the default prescription length for statins from 30 days to 90 days rapidly raised the proportion of patients receiving a 90-day prescription. This simple nudge to clinicians to offer patients a longer prescription nearly eliminated racial, ethnic, insurance-based, and income-based disparities in prescription length, in a new study by LDI Senior Fellows Alexander Fanaroff, Michael Harhay, Maryanne Peifer, Kevin Volpp, Kit Delgado, and colleagues. The results suggest a way to ensure all patients have a sufficient medication supply.

Statin medications are recommended for many individuals at risk for cardiovascular disease. People who have medications readily available have lower death rates than those who do not. “A longer prescription length means patients don’t have to fill their prescription as often,” Fanaroff said. “This might help them regularly take their medication without missing days.”

The researchers used health system data from a primary care system to identify inequities in statin prescription length. Individuals with Hispanic ethnicity or Black race, Medicaid insurance, or residence in a ZIP code with a median annual household income below $50,000 were less likely to have a 90-day statin prescription than people with non-Hispanic white or Asian race or ethnicity, Medicare or commercial insurance, or residence in a higher-income area.

“Reasons for these disparities might be related to past payer restrictions or clinicians’ beliefs about what patients can afford,” Fanaroff said, “but with generic statins, patient costs may be a smaller concern.”

Changing Default Length Increased—and Equalized—90-Day Prescriptions

Fanaroff and colleagues then changed the default statin prescription length from 30 to 90 days in the prescribing system used by clinicians. They monitored the subsequent 18,500 statin prescriptions through January 2024. Within weeks of the prescription-length change, the proportion of all patients receiving a 90-day prescription increased by more than 20 percentage points (Figure 1).

After the change, 90% of nearly all groups had 90-day statin prescriptions, greatly diminishing the baseline disparities in prescription length by racial, ethnic, insurance type, and income groups. In the group with Hispanic ethnicity, only 85% had 90-day prescriptions, but this reduced the previous disparity with the non-Hispanic white group by 13 percentage points.

Clinicians changed the prescription length back to 30 days for about 8% of patients. “This is likely because of patient preference,” Fanaroff said, “and shows clinicians and patients still had freedom of choice about their prescription.”

This study addressed only clinician prescribing behavior. The impact on patients, including their prescription fills or cardiovascular health, is unknown. The authors will follow up by studying whether the 90-day prescription length helps patients regularly take their medication and, eventually, improve their cardiovascular health.

The study, “Change in Default Prescription Length and Statin Prescribing Behavior” was published on April 7, 2025, in JAMA Internal Medicine. Authors include Mili Mehta, Alexander C. Fanaroff, Corinne M. Rhodes, Aria Xiong, Christopher K. Snider, E. Madeline Grenader, Michael O. Harhay, Nune Mehrabyan, Maryanne K. Peifer, Kevin G. M. Volpp, and M. Kit Delgado.