Disease Burden, Chronic Pain Cases Remain High Among US Adults

The incidence and burden of chronic pain is higher than that of other chronic diseases and requires improved measures of prevention and early management, according to study findings published in JAMA Network Open.  

Chronic pain is a common condition within the United States and presents a heavy burden on the individual and society. However, epidemiological research on the topic remains incomplete, as certain communities and groups are susceptible to underreporting and under-management of pain symptoms. For the study, researchers aimed to assess the incidence and characteristics of chronic pain lasting at least 3 months and high-impact chronic pain (HICP) that limits activities of everyday life.

The researchers looked at data from the 2019-2020 National Health Interview Survey Longitudinal Cohort (NHIS-LC). The primary outcomes were incidence rates of both chronic pain and HICP. Incidence rates were reported per 1000 person years (PYs) of follow-up. Secondary outcomes included demographic characteristics and incidence rates of chronic pain among different demographic groups.

In total, 10,415 individuals were included in the sample. Just over half were women (51.7%), 54% were aged between 18 and 49, and 70.5% did not have college degrees. The majority of patients were White (72.6%), while 16.5% identified as Hispanic. The mean follow-up was 1.3 years.

At baseline, 40.3% of patients reported having no pain, 38.9% nonchronic pain, and 20.8% reported chronic pain. The majority of patients reported the same pain status at baseline in 2019 and follow-up in 2020.

The 1-year cumulative incidence for chronic pain and HICP were 6.3% and 1.4% at follow-up, respectively, among those who reported no pain at baseline. A total of 14.9% of patients reporting nonchronic pain at baseline had progressed to chronic pain at follow-up, while 10.4% of patients with baseline chronic pain reported being pain free later on.

Differences in incidence rates of chronic pain and HICP were noted according to baseline pain status. Incidence rates of chronic pain and HICP were 52.4 (95% CI, 44.9-59.9) cases per 1000 PY and 12.0 (95% CI, 8.2-15.8) cases per 10000 PY at follow-up, respectively, among those reporting no initial pain.

Rates of chronic pain at follow-up were higher among patients with nonchronic pain at baseline (116.2 cases [95% CI, 105.3-127.1] per 1000 PY), as well as among those initially reporting chronic pain (462.0 [95% CI, 439.7-484.3] cases per 1000 PY). Patients with chronic pain and HICP at baseline were associated with high rates of HICP at follow- up (189.7 [95% CI, 149.4-230.1] cases per 1000 PY and 361.2 [95% CI, 265.6-456.8] cases per 1000 PY, respectively).

Patients of more advanced age reported higher rates of chronic pain, as well as those without a college degree, regardless of baseline pain status. Rates of chronic pain at follow-up were higher among patients who were non-Hispanic reporting nonchronic pain at baseline vs those identifying as Mexican. No differences in rates of chronic pain were reported between men and women.

This study was limited by a lack of data on the underlying causes of pain. Additionally, only a small sample of American Indian or Alaska Native populations were included in the study population. Lastly, the small number of patients reporting HICP prevented further subgroup analysis.

The researchers concluded, “These longitudinal data emphasize the high disease burden of chronic pain in the US adult population and the need for early management of pain.”