Reliability of New Indices of Radiographic Osteoarthritis of the Hand and Hip and Lumbar Disc Degeneration

Objective: To develop a method for assessing the presence and severity of radiographic features of osteoarthritis (OA) of the hip and hand, and thoracic and lumbar disc degeneration.

Methods: An atlas illustrating scoring of individual radiographic features and summary grades for individual joints was developed. Three readers evaluated 31 pelvic films, 27 hand films, and 25 lateral lumbar and thoracic spine films selected from a community based sample of healthy elderly women. Interrater agreement between the 3 readers, and test-retest agreement for one of the readers, were estimated by the intraclass correlation coefficient (ICC) and kappa statistic.

Results: Interrater agreement (ICC, unless otherwise noted) for individual radiographic features of the hip ranged from 0.66 for osteophytes to 0.80 for narrowing. For the 9 interphalangeal (IP) joints of the hand, agreement ranged from 0.42 (kappa) for sclerosis to 0.93 for narrowing, and for the lumbar spine from 0.55 (kappa) for sclerosis to 0.95 for narrowing. Interrater agreement for summary grades of radiographic findings was as follows: hip, 0.81; 5 distal interphalangeal joints (DIP), 0.89; 4 proximal interphalangeal joints (PIP), 0.82; and lumbar spine, 0.93. Intrarater agreement for summary grades was as follows: hips, 0.79; 5 DIP, 0.86; 4 PIP, 0.81; and lumbar spine, 0.90.

Conclusion: We have developed reliable indices of the presence and severity of radiographic features of hip and hand OA and spinal disc degeneration for use in epidemiologic studies. The assessment includes grading of individual radiographic features, which allows for the independent variation in these features often found in OA and a summary grade of disease that is derived from the presence and severity of individual features.