A new study finds that people who live with someone with a prescription for opioid painkillers are more likely to get their own prescription for opioids.

The findings come from an analysis of 12.6 million people living in a household in which someone was prescribed opioids, and 6.4 million people in homes in which someone was prescribed nonprescription steroidal anti-inflammatory drugs (NSAIDs) for pain.

The study found 11.83 percent of people living with someone prescribed opioids and 11.11 percent of people living with a person prescribed NSAIDs started taking opioids over the next year, Reuters reports.

While the increase in risk was small, lead study author Marissa Seamans of the Johns Hopkins University Bloomberg School of Public Health in Baltimore said it matters “because millions of opioids are prescribed and have harmful effects.”

The study appears in JAMA Internal Medicine.