Analysis of the discordance between radiographic changes and knee pain in osteoarthritis of the knee

Objectives. To analyze cross sectional data from the National Health and Nu trition Examination Survey (NHANES I) concerning 3 indicators of osteoarthr itis (OA) of the knee. radiographic evidence of structural damage, self-rep orted knee pain, and self-report of a diagnosis of arthritis at any joint b y a physician. Methods. Analysis of NHANES I data for 6880 persons ages 25-74 in the Unite d Stares. Results. Radiographic stage 2-4 knee OA was found in 319 subjects (3.7%); only 47% of these individuals reported knee pain, and only 61% rep orted that a physician had told them that they had arthritis. Knee pain was reported by 1004 subjects (14.6%), only 15% of whom had radiographic stage 211 changes of OA, and 59% of whom reported having a diagnosis of arthriti s by a physician. A report of arthritis diagnosed by a physician was given by 1762 subjects (25.6%), of whom only 11% had stags 2-4 radiographic knee OA and 34% reported knee pain. Conclusion, Substantial discordance exists in this population based study b etween radiographic OA of the knee versus knee pain, versus a diagnosis of arthritis by a physician. These phenomena may be important in the design of clinical research studies, as well as in criteria for OA.