Prevalence of Incident and Persistent Chronic Pain

"In this cohort study, nearly two-thirds (61.4%) of adults with chronic pain in 2019 continued to have chronic pain in 2020. While 14.9% of those with nonchronic pain reported chronic pain 1 year later, only 6.3% of those pain free in 2019 developed incident chronic pain and only 1.4% exhibited an onset of HICP. Lower educational attainment and older age were associated with higher rates of chronic pain in 2020 regardless of pain status in 2019. Of note, the incidence of chronic pain (52.4 cases per 1000 PY) was high compared with other chronic diseases and conditions for which the incidence in the US adult population is known, including diabetes (7.1 cases per 1000 PY),27 depression (15.9 cases per 1000 PY),28 and hypertension (45.3 cases per 1000 PY).29

"Although chronic pain is sometimes assumed to persist indefinitely, our finding that 10.4% of adults with chronic pain experienced improvement over time is consistent with previous evidence from studies in Denmark,30 Norway,31 Sweden,32 and the UK,33 which revealed rates ranging from 5.4% to 8.7% (eTable 2 in Supplement 1). Also similar across our study and these 4 studies30-33 were the rates of 1-year cumulative incidence for chronic pain at baseline, which ranged from 1.8%30 to 8.3%32 (eTable 2 in Supplement 1). The observed differences likely reflect variability in study methods, including how chronic pain was defined, the populations studied, and the length of follow-up. The rates for persistent chronic pain varied from 47.9%30 in the youngest cohort (aged ≥16 years at entry) to 93.5%32 in the oldest cohort (aged ≥65 years at entry). These rates suggest an age effect consistent with our finding that participants 50 years or older had a 29% higher adjusted RR of persistent pain than younger participants. Our ongoing research examines the underlying factors that may explain the observed differences in chronic pain incidence, persistence, and recovery rates in our study."