As the United States is in the midst of a prescription opioid epidemic, doctors, legislators, and law enforcement are attempting to keep drugs out of the hands of people seeking them for their euphoric highs.

One major problem remains, however.

Leftover opioids

The pills are still as easy to obtain as opening someone’s medicine cabinet.

A survey from Johns Hopkins Bloomberg School of Public Health found that more than 60 percent of people who were prescribed opioid painkillers reported having leftover pills.

More than 60 percent of those people reported keeping them to use at a later time. Less than 10 percent reported keeping them behind lock and key.

Read More: Prescription Drugs Are Leading to Heroin Addictions »

Storing and Sharing

Alene Kennedy-Hendricks, Ph.D., the study leader and an assistant scientist in the Department of Health Policy and Management at Johns Hopkins Bloomberg School of Public Health, said opioid painkiller prescription patterns have contributed to the epidemic of addiction and overdose in the United States.

“It's not clear why so many of our survey respondents reported having leftover medication, but it could be that they were prescribed more medication than they needed,” she said in a press release.

The survey, which involved 1,032 U.S. adults, and was published this week in JAMA Internal Medicine, also showed that one in five people reported sharing their medication with someone else, often so that person could treat pain.

Many who receive the medications for legitimate reasons often don’t get information on safely storing these medications or how to properly dispose of them.

“We don't make it easy for people to get rid of these medications,” Kennedy-Hendricks said. “We need to do a better job so that we can reduce the risks not only to patients but to their family members.”

A 2014 study appearing in Internal Medicine found that many high-risk opioid users continue to obtain prescriptions from doctors, while others got them from relatives and friends for free or at a cost.

And the cost to society continues to show.

While there hasn’t been a large uptick in complaints of pain in the United States, sales of prescription opioids nearly quadrupled from 1999 to 2014, according to the U.S. Centers for Disease Control and Prevention (CDC).

But who are getting these pills?

A lot of people, actually, and it’s often dependent on where they live or their healthcare provider.

Read More: Treating Chronic Pain in an Opioid Epidemic »

Opioid Prescription Rates Vary

The CDC estimates that one out of five patients with noncancer pain or pain-related diagnoses are prescribed opioids.

The most prescriptions come from the fields of pain management, surgery, or physical rehabilitation.

What happens too often is someone is injured or has surgery, is given prescription painkillers, and becomes addicted. The drugs are, after all, prescription forms of heroin — and sometimes stronger — and can be highly addictive.

While opioids play an important role in treating pain, their widespread use and accessibility have fueled not only a prescription drug crisis, but have also led to a surge in heroin. Heroin, also an opioid, is often cheaper than pills.

A study out of the Harvard Medical School released this week found that nearly 15 percent of patients who have never received an opioid prescription received one while hospitalized under Medicare.

Those rates, however, vary nearly twofold between hospitals. Some, the researchers say, discharged as many as 20 percent of patients with an opioid prescription.

Among those patients, 40 percent were still taking opioids 90 days after they were discharged from the hospital.

Since 44 people in the United States die every day from a prescription drug overdose, Anupam Jena, lead author of the study and a physician at Massachusetts General Hospital, said these numbers raise concern.

“It's critical that we understand hospital prescribing patterns so that we can make sure we are prescribing these medications safely and effectively without fueling this deadly crisis,” he said in a press release.

Besides variations from hospital to hospital, prescription rates vary by state. According to the CDC, states with the highest opioid prescription rates write nearly three times as many as those with the lowest rates.

Local, state, and federal authorities continue to crack down on “pill mills,” or facilities that dole out opioids and other prescriptions by the hundreds with little to no medical justification.

As a result, a growing number of doctors are facing charges for murder and other crimes stemming from the deaths of their patients resulting from those prescriptions.

Read More: More ‘Pill Mill’ Doctors Being Prosecuted Amid Opioid Epidemic »