Identification of high-impact chronic pain in adolescents with musculoskeletal pain.

High-impact chronic pain (HICP) describes pain that interferes substantially with daily functioning and is associated with diminished quality of life, yet brief tools to identify and track HICP in adolescents are lacking. The 3-item Pain, Enjoyment, and General Activity (PEG) scale derived from the Brief Pain Inventory offers a promising rapid measure, but its psychometric properties and an empirically derived HICP cut-off score based on PEG have not been established in pediatric chronic pain. The present study examined convergent validity, classification accuracy, and a PEG cut-off for HICP in 263 adolescents (10-18 years; 84.4% female) with chronic musculoskeletal pain receiving tertiary pain care. The PEG was strongly associated with primary clinical variables: functional disability ( r = 0.63), quality of life ( r = -0.56), and pain intensity and unpleasantness ( r = 0.58, 0.61), and strongly-to-moderately associated with secondary clinical variables: fatigue ( r = 0.53), depression ( r = 0.49), and pain catastrophizing ( r = 0.49), with modest associations with sleep and anxiety ( r = -0.31, 0.25). Receiver operating characteristic analysis indicated that across all 4 primary clinical variables, the PEG demonstrated the strongest discrimination of upper-tertile functional disability scores (Functional Disability Inventory ≥28, area under the curve = 0.81, sensitivity 0.75, specificity 0.76, positive predictive value 0.64, Youden index 0.51, PEG score cut-off 6) and was cross-validated against pain intensity, pain unpleasantness, and quality-of-life variables. The PEG represents a promising brief monitoring and clinical status tool to support risk-stratified care and clinical research in pediatric chronic musculoskeletal pain.