Validation of the Spanish Version of the Itch Severity Scale: The PSEDA Study

Background and objectivesThe Itch Severity Scale (ISS) facilitates objective assessment of the intensity of pruritus. The aim of this study was to validate a Spanish version of the ISS in patients with atopic dermatitis.Material and methodsA prospective epidemiological study was undertaken in patients diagnosed with atopic dermatitis at least 1 year previously and a control group without the disease. Patients with atopic dermatitis were stratified according to the status of the lesions (active or inactive) and questionnaires were completed at baseline and 3-month and 6-month follow-up. Data were collected on sociodemographic variables relating to atopic dermatitis (including the modified Eczema Area and Severity Index [mEASI]), concomitant disease, and patient measures such as ISS, Dermatology Life Quality Index (DLQI), and Children's DLQI (cDLQI).ResultsA total of 207 children (2-17 years) were included: 56 control subjects, 103 patients with active lesions, and 48 with inactive lesions. The mean (SD) age of the participants in this age group was 8.1 (4.0) years. A total of 261 adults (≥ 18 years) were included: 89 control subjects, 124 patients with active lesions, and 48 with inactive lesions. The mean age of the adult participants was 32.3 (13.4) years. A response rate of > 80% was obtained on the pediatric ISS (feasibility) and the responses correlated with the mEASI and cDLQI at baseline (P < .001) as an indicator of validity. An effect size of 0.988 was observed (sensitivity to change) along with a Chronbach α of 0.840 (internal consistency). A response rate of >95% was obtained on the adult ISS (feasibility) and the responses correlated with the mEASI and DLQI at baseline (P < .001) as an indicator of validity. An effect size of 1.0 was observed (sensitivity to change) along with a Chronbach α of 0.825 (internal consistency).ConclusionsThe Spanish version of the ISS is feasible, valid, sensitive to change, and displays good reliability based on internal consistency in both children and adults.

ResumenIntroducción y objetivoEl cuestionario Itch Severity Scale (ISS) permite evaluar objetivamente la intensidad del prurito. El presente estudio pretende validar la versión española del cuestionario ISS en pacientes con dermatitis atópica (DA).Materiales y métodosEstudio epidemiológico prospectivo, incluyendo pacientes con DA de más de un año de evolución y un grupo control sin DA. Los pacientes con DA se estratificaron según actividad de las lesiones (activas/inactivas), realizando una visita basal y dos de seguimiento (3 y 6 meses). Se recogieron variables sociodemográficas, relacionadas con la DA (incluyendo el modified Eczema Area and Severity Index o mEASI), enfermedades concomitantes y medidas del paciente como ISS, Dermatology Life Quality Index (DLQI) o Children's DLQI (cDLQI).ResultadosSe incluyeron 207 pacientes pediátricos (2-17 años): 56 controles, 103 con lesiones activas y 48 inactivas, con una edad media (DE) de 8,1(4,0) años. Los adultos fueron 261 pacientes (≥ 18 años): 89 controles, 124 con lesiones activas y 48 inactivas, con una edad media (DE) de 32,3 (13,4) años.ISS pediátricos: tasa de respuesta > 80% (factibilidad), correlacionándose con mEASI y cDLQI en visita basal (p < 0,001) (validez), effect size de 0,988 (sensibilidad al cambio) y alpha de Cronbach de 0,840 (consistencia interna).ISS adultos: tasa de respuesta fue > 95% (factibilidad), correlacionándose con mEASI y DLQI en visita basal (p < 0,001) (validez), effect size de 1,0 (sensibilidad al cambio), alpha de Cronbach de 0,825 (consistencia interna).ConclusionesLa versión española del ISS se mostró factible, válida, sensible al cambio y fiable en términos de consistencia interna, tanto en niños como en adultos.