Estefanía Galeano-Piedrahita, Servicio de Dermatología, Universidad CES, Medellín, Colombia
Ana M. Muñoz, Servicio de Dermatología, Aurora Centro Especializado Cáncer de Piel, Medellín, Colombia
Ángela M. Londoño-García, Servicio de Dermatología, Universidad CES, Medellín, Colombia
César González-Ardila, Servicio de Dermatología, Universidad El Bosque, Bogotá, Colombia
Milton Mejía-Montoya, Servicio de Dermatología, Clínica Vida Fundación Colombiana de Cancerología, Medellín, Colombia
Elsa M. Vásquez-Trespalacios, Servicio de Epidemiología, Universidad CES, Medellín. Colombia
Introduction: Different scales have been described that assess the severity of nail psoriasis. The objective is to evaluate the intra-observer reliability of the military modified nail psoriasis area and severity index (NAPSImm) to know its usefulness as a clinimetric tool and to compare it with the existing indices to identify advantages and disadvantages. Method: It is a cross-sectional analytical study, where 42 patients over 18 years of age with nail psoriasis were evaluated. Four evaluators (2 experts in psoriasis, 1 dermatologist and 1 dermatology resident) evaluated the NAPSI, NAPSI of a target nail and NAPSImm scales by means of photographs for each patient in a blinded way and the intraobserver reliability was subsequently calculated. Results: 42 patients were included, 25 (59.5%) men and 17 (40.5%) women with an average age of 50.40 years. The four evaluators analyzed 100% of the cases, with an intraclass correlation coefficient for NAPSI of 0.837 (95% CI 0.739-0.905), for the target nail NAPSI of 0.576 (95% CI 0.752-2.356) and for the NAPSImm of 0.590 (95% CI 0.342-0.761). Conclusions: The four evaluators presented a substantial degree of agreement. The NAPSI scale continues with a high degree of agreement, almost perfect, compared to the NAPSI of a target nail and the NAPSImm, for which the degree of agreement was moderate, but when performing subgroup analysis, the degree of agreement for the NAPSImm was substantial. If an agreement is reached from the beginning to always evaluate the same nail, the NAPSImm could be used instead of the NAPSI.
Keywords: Nail disease. Psoriasis. Severity of illness index.