RELIABILITY TESTING OF THE DERMATOLOGY INDEX OF DISEASE SEVERITY (DIDS) - AN INDEX FOR STAGING THE SEVERITY OF CUTANEOUS INFLAMMATORY DISEASE

Objectives: To describe a new severity of illness index for inflammato ry skin disease called the Dermatology Index of Disease Severity (DIDS ), and to show its preliminary use and reliability in staging disease in patients with psoriasis and dermatitis. Design: Interobserver ratin g study using the DIDS with as many as 10 observers independently rati ng the same patient at a single point in time. Setting: Ambulatory car e clinics at an academic medical center with patients from various soc ioeconomic backgrounds. Patients: Thirty-four patients with psoriasis and 15 patients with dermatitis were included in the study. Main Outco me Measures: The severity of illness for each patient was rated as 1 o f 5 stages: 0, no evidence of clinical disease; I, limited disease; II , mild disease; III, moderate disease; and IV, severe disease. The deg ree of interobserver concordance was measured by the Cohen kappa stati stic. Results: All 5 stages were represented in the study of patients with psoriasis. The overall kappa statistic was 0.76, which is defined as substantial interobserver concordance. The use of the instrument i n dermatitis showed good consensus in staging, where the kappa statist ic was 0.41. Conclusion: We introduce an easy and efficient instrument for staging the severity of illness in inflammatory cutaneous disease s. The reliability of the DIDS is demonstrated in patients with psoria sis and in patients with dermatitis.