One in five Americans suffer from chronic pain, limiting their daily function and causing nearly $300 billion in lost productivity each year, according to new work by Harvard University researchers.

An estimated 50.2 million Americans, or 20.5% of the adult population, report pain most or every day, the researchers found in a paper for the medical journal Pain, published April 20. Of these, 22.1 million are bothered "a lot" by hip, knee or foot pain, while 20.5 million have serious back pain. 

Previous research has established that chronic pain is twice as prevalent in women as in men, with genetics accounting for part of the explanation.

"When left untreated, chronic pain can have a pretty profound impact," said lead author Jason Yong, a medical director in the pain management center at Brigham and Women's Hospital, an affiliate of Harvard Medical School. "If we are able to help manage it and decrease it a little bit, we can make meaningful improvements in people's lives." 

Yong wrote the paper alongside Peter Mullins, also of Brigham and Women's, and Neil Bhattacharyya, of Harvard Medical School.

The researchers used data from the Centers for Disease Control and Prevention's National Health Interview Survey, which had 31,997 adult respondents who self-reported their health status. In 2019, the survey added a series of questions about chronic pain, which the Harvard researchers exploited for their study, extrapolating the results to cover the entire U.S. adult population. 

Adults with chronic pain missed an average of 10.3 days of work per year, compared to 2.8 days for those without it. Based on this figure, Yong and his colleagues calculated that missed days due to chronic pain correspond to a $296 billion drag on gross domestic product each year, including about $80 billion in lost wages. 

That figure does not include medical expenses such as doctors' visits and prescriptions, which Yong said likely push the total cost of pain far higher. 

"This number of about $300 billion for the total value of lost productivity does not include the direct costs, so the complete economic impact that pain has on America is far greater," he said. "I would guess that [including medical costs] would double that number." 

Nearly half of respondents with chronic pain said they occasionally missed work due to a health problem, compared to just 15% of those without it. 

The research also covered what treatments patients use to address chronic pain. 

One in five people with chronic pain, or 9.4 million respondents, had tried physical therapy. Massage was the second most common treatment, with 8.8 million or 17.6% of pain patients having tried that treatment, even though the researchers said there was "a dearth of high-quality evidence" for massage's effectiveness in addressing pain. 

Psychological treatments for reducing pain were far less common. Just 7.8% of pain patients had tried meditation or guided imagery, while 2.6% had tried self-management programs, 1.9% had tried talk therapy and 0.9% had utilized peer support groups. 

"What really stuck out was the underutilization of behavioral help," said Yong. 

The study did not touch on patients' opioid use. More than 191 million opioid prescriptions for opioids were written in the U.S. in 2017, according to the CDC.  

Yong, who also treats patients in a clinical setting in addition to his research, said the study shows that Americans should take a more varied approach to pain by combining physical therapy with meditation, for example. 

"The hallmark for how we approach treating a patient dealing with pain and suffering from pain is the multimodal, multidisciplinary approach," he said. "Over the past few years, insurance companies have been more amenable to approving services from chiropractic manipulation to acupuncture, and that just goes to adding to the different disciplines and specialties that are helping to treat pain." 

Since the study used data from 2019, it did not incorporate the effects of the coronavirus pandemic on pain, which Yong expects will be wide-ranging as restrictions drastically changed Americans' lifestyles. Anecdotally, he said some of his patients who had been successfully managing chronic pain have had their conditions deteriorate over the past year. 

"I would not be surprised if chronic pain has also increased because we are seeing a lot of patients in our clinic," he said. 

Yong is eagerly awaiting the release of the next National Health Interview Survey in 2022. He expects researchers will add to their understanding of COVID-19's effects on pain through analyses of that data in 2023 and 2024. 

In the meantime, Yong is working on a follow-up study using the 2019 survey data. Since the Pain paper did not include breakdowns by factors like race or income, he plans to publish another paper incorporating demographic and social determinants of health in the future. 

The paper, "The prevalence of chronic pain among adults in the United States," published April 20 in Pain, was authored by Jason Yong and Peter Mullins, Brigham and Women's Hospital; and Neil Bhattacharyya, Harvard Medical School.