The incidence of chronic pain is high in the United States

New cases of chronic pain – defined as pain felt most days or every day for 3 months – occurred more frequently than new cases of other common chronic conditions, according to US survey data.

The incidence of chronic pain was 52.4 cases per 1,000 person-years, reported Richard Nahin, MPH, PhD, of the NIH in Bethesda, Maryland, and his co-authors.

This was higher than the incidence of diabetes (7.1 cases/1,000 person-years), depression (15.9 cases) and hypertension (45.3 cases), the researchers said in Open JAMA Network.

In addition, chronic pain was persistent: almost two-thirds (61.4%) of adults with chronic pain in 2019 continued to suffer from it in 2020.

The findings come from National Health Survey (NHIS) data and are the first national estimates of the incidence of chronic pain.

Recent data from the NHIS showed that the prevalence of chronic pain in the United States was around 21%, affecting around 51.6 million adults. High-impact chronic pain – pain severe enough to restrict daily activities – affected 17.1 million people.

“Understanding incidence, beyond overall prevalence, is critical to understanding how chronic pain manifests and changes over time,” Nahin said in a statement. “These pain progression data underscore the need for increased use of multimodal, multidisciplinary interventions that can alter the course of pain and improve outcomes for people.”

The NHIS is a cross-sectional survey conducted annually by the National Center for Health Statistics. Nahin and his co-authors assessed 10,415 adults who participated in the 2019 and 2020 surveys. Participants with chronic pain in both time periods were considered to have persistent chronic pain.

The sample included 51.7% women. More than half of the study population – 54% – was between the ages of 18 and 49. Most participants (72.6%) were Caucasian; 16.5% were Hispanic and 12.2% were black. Most (70.5%) were not university graduates.

At baseline (2019), 40.3% of participants reported no pain, 38.9% reported non-chronic pain, and 20.8% reported chronic pain.

Among people without pain in 2019, the rate of incident chronic pain was 52.4/1000 cases (95% CI 44.9-59.9). The incident high impact chronic pain rate was 12.0 (95% CI: 8.2-15.8). Lower education and older age were associated with higher rates of chronic pain in 2020, regardless of pain status in 2019.

In 2020, the rates of chronic persistent pain and chronic persistent high-impact pain were 462.0 and 361.2 cases per 1,000 person-years, respectively.

Of those reporting non-chronic pain in 2019, 14.9% had progressed to chronic pain at follow-up. Of those who reported chronic pain in 2019, 10.4% had fully recovered (pain free) by 2020.

“Although it is sometimes assumed that chronic pain persists indefinitely, our finding that 10.4% of adults with chronic pain experienced improvement over time is consistent with previous evidence from studies in Denmark, Norway, Sweden and the UK, which found rates ranging from 5.4% to 8.7%,” the researchers note.

The study did not include information about the underlying causes of the pain, and survey data was only collected twice over 2 years of follow-up, Nahin and his co-authors acknowledged. It is possible that people with new or persistent chronic pain or high-impact chronic pain were less likely to participate in the 2020 follow-up survey, which may have led to underestimated rates.