Science2019United Stateshigh confidence

Approximately 1 in 5 U.S. adults had chronic pain in 2019.

Notes on verification

Confirmed by CDC NHIS data brief and independent peer-reviewed study in PAIN journal, both reporting ~20.4-20.5% prevalence, consistent across multiple secondary sources. [cascade flags: aggregator_dropped_primary_exists | tier=silver indep_score=0.925 clusters=2 claim_tier=notable]

Sources