Prevalence and Factors Associated With High-Impact Chronic Pain in Knee Osteoarthritis: The Johnston County Health Study.

Pain is a hallmark symptom of knee osteoarthritis (KOA), yet intensity and severity vary widely among individuals. There is a knowledge gap in understanding key characteristics of high-impact chronic pain (HICP) within the context of KOA. Therefore, our first purpose was to examine the prevalence of HICP in a cohort of individuals with radiographic evidence of KOA, and our second purpose was to assess patient-level factors associated with HICP. Data from the Johnston County Health Study were used to compare those with and without HICP. Variables included sociodemographic factors, clinical factors, health care use, and psychosocial distress. HICP status was classified with Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference and Physical Function measures. The results indicated that 15.5% (48/310) of participants were classified as having HICP when the PROMIS-Pain Interference cutoff score was used, while 21.2% (66/310) were classified as having HICP with a PROMIS-Physical Function cutoff score. Multivariable analyses indicated that HICP was consistently characterized by increased kinesiophobia and somatization, regardless of PROMIS measure used for HICP status. A secondary insight was that HICP was not consistently characterized by sociodemographic and clinical variables, as these findings were dependent on PROMIS measure used. These findings could be used to develop intervention approaches specific to individuals with KOA and to inform future investigations of sociodemographic and clinical factors associated with HICP. PERSPECTIVE: These findings provide additional information on the characterization of HICP for individuals with KOA. There was consistency in psychosocial factors associated with HICP, while sociodemographic and clinical factors varied based on how HICP status was defined.