Comparison of the original and the modified Larsen methods and the Sharp method in scoring radiographic progression in early rheumatoid arthritis

Abstract

Objective: To compare the original Larsen method and the proposed modification of the Larsen method with omission of scoring soft tissue swelling and periarticular osteoporosis, and the Sharp method in measurement of radiographic progression in early rheumatoid arthritis (RA).

Methods: Radiographs of hands and feet were assessed by the 3 scoring methods at Months 0 and 12 in 83 patients with recent onset RA. Sensitivity to change was determined using standardized response mean (SRM).

Results: Highly significant radiographic progression was observed by all 3 methods. The modified Larsen method showed the largest SRM (0.88), but the differences were slight between the 3 scoring methods (SRM 0.80 for the original Larsen method, SRM 0.72 for the Sharp method). High interobserver reproducibility was observed for all methods tested.

Conclusion: In early RA the sensitivity to change of all 3 scoring methods was high, but in this patient population the newly modified Larsen method was the most responsive method.