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November 1997

Reliability Testing of the Dermatology Index of Disease Severity (DIDS)An Index for Staging the Severity of Cutaneous Inflammatory Disease

Author Affiliations

From the Departments of Dermatology (Drs Faust, Gonin, Chuang, Lewis, and Farmer) and Medicine (Drs Faust, Gonin, and Melfi), Indiana University Medical Center, and The Roudebush Veterans Affairs Medical Center (Dr Chuang), Indianapolis, Ind.

Arch Dermatol. 1997;133(11):1443-1448. doi:10.1001/archderm.1997.03890470121019

Objectives:  To describe a new severity of illness index for inflammatory 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 rating study using the DIDS with as many as 10 observers independently rating the same patient at a single point in time.

Setting:  Ambulatory care clinics at an academic medical center with patients from various socioeconomic backgrounds.

Patients:  Thirty-four patients with psoriasis and 15 patients with dermatitis were included in the study.

Main Outcome Measures:  The severity of illness for each patient was rated as 1 of 5 stages: 0, no evidence of clinical disease; I, limited disease; II, mild disease; III, moderate disease; and IV, severe disease. The degree of interobserver concordance was measured by the Cohen κ statistic.

Results:  All 5 stages were represented in the study of patients with psoriasis. The overall κ statistic was 0.76, which is defined as substantial interobserver concordance. The use of the instrument in dermatitis showed good consensus in staging, where the κ statistic was 0.41.

Conclusion:  We introduce an easy and efficient instrument for staging the severity of illness in inflammatory cutaneous diseases. The reliability of the DIDS is demonstrated in patients with psoriasis and in patients with dermatitis.Arch Dermatol. 1997;133:1443-1448