Validity and reliability of the BODI for assessing damage in Behcet's disease.

Objective: In the present study, we aimed to validate the Behçet's syndrome Overall Damage Index (BODI) and compare its performance with that of vasculitis damage index (VDI) in Iranian patients with BD.

Methods: This study included 274 patients with a diagnosis of BD and median follow-up of 40 months. The medical records of the patients were reviewed and the demographic characteristics, disease activity status, clinical manifestations, and data on organs damage were collected from all patients.

Results: To evaluate the construct/convergent validity, BODI and VDI were applied to all participants. We found a good correlation between BODI score and VDI score. There was a significant and strong correlation between physician global assessment with BODI (r = 0.869, P = 0.001) and VDI (r = 0.817, P = 0.001). The ability of BODI to determine the accumulation of damage over time was assessed by analyzing the changes in BODI score over time. The increase in BODI score was occurred in 53 (19.3%) patients. In comparison, the increase in VDI score occurred in 36 (13.1%) patients. The increase in median BODI was significantly more than median VDI (P < 0.001). Multiple linear regression analysis showed that age at disease onset, disease duration, and disease severity were independent predictors of BODI scores. Reliability of BODI was examined by comparing the BODI scores as determined by two independent assessors in 100 patients. Cronbach's α was 0.942.

Conclusion: The BODI demonstrated acceptable validity and reliability in assessing BD-related damage in Iranian patients with BD.