J Investig Allergol Clin Immunol 2009; Vol. 19(1): 35-42 © 2009 Esmon Publicidad ORIGINAL ARTICLE International Study of Wheezing in Infants (EISL): Validation of Written Questionnaire for Children Aged Below 3 Years AC Dela Bianca, 1 GF Wandalsen, 1 K Miyagi, 1 L Camargo, 1 D Cezarin, 1 J Mallol, 2 D Solé 1 1 Department of Pediatrics, Federal University of São Paulo-Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil 2 Department of Pediatric Respiratory Medicine, Hospital CRS El Pino, University of Santiago, Chile ■ Abstract Background: The multicenter International Study of Wheezing in Infants (EISL) was developed to study the prevalence of recurrent wheezing and related risk factors in infants during the fi rst year of life using a written questionnaire (EISL-WQ). Objectives: To constructively validate a modifi ed, shortened version of the EISL-WQ in children up to 36 months of age in São Paulo, Brazil, and to verify its usefulness in diagnosing probable asthma in these children. Methods: The parents of 170 infants aged 12 to 36 months answered the shortened EISL-WQ in an emergency room and were asked if their child was currently wheezing before a diagnosis was made by a physician. The consistency between parent perception and the physician’s diagnosis was then evaluated. A second group (n = 55) participated in the validation of the short-term repeatability of the shortened questionnaire by completing it twice (mean interval, 23 days). Result s: There was good agreement between parent perception of wheezing and the physician’s diagnosis following auscultation (Kappa statistic = 0.7; odds ratio = 38.33; 95% confi dence interval, 15.8 to 92.8; P< .001); sensitivity (82.8%), specifi city (85.0%), positive predictive value (81.5%), and negative predictive value (86.0%) were all high. The short-term repeatability of the shortened version of the EISL-WQ was also high (κ > 0.75). Questions added to the shortened EISL-WQ improved the internal consistency of the original questionnaire (Cronbach α = 0.823, P< .001) and a high Youden index was found for patients defi ned as probable asthmatics. Conclusions: The shortened version of the EISL-WQ translated into Portuguese has high internal consistency, and is a valid, reliable, and reproducible instrument for obtaining data on wheezing in children below 36 months of age and for identifying those with probable asthma. Key words: Asthma. Infants. Written questionnaire. Reproducibility. Validation. ■ Resumen Antecedentes: El Estudio Internacional de Sibilancias en lactantes (EISL) fue desarrollado para valorar la prevalencia de las sibilancias recurrentes y factores de riesgo relacionados en niños durante el primer año de vida usando un cuestionario escrito (EISL-CE). Objectivos: Validar constructivamente una versión reducida y modifi cada de EISL-CE en niños con edades inferiores a 36 meses en São Paulo, Brasil, y comprobar su utilidad diagnosticando el probable asma en estos niños. Métodos: Los padres de 170 niños con edades comprendidas entre 12 y 36 meses respondieron a una versión reducida de EISL-CE en una sala de urgencias y se les preguntó si el niño presentaba sibilancias en ese momento antes de ser diagnosticado por un médico. Se evaluó la consistencia entre la percepción de los padres y el diagnóstico del médico. Un segundo grupo (n = 55) participó en la validación de la reproducibilidad a corto plazo del cuestionario reducido rellenándolo en dos ocasiones (intervalo medio de tiempo, 23 días). Resultados: Existía una buena concordancia entre la percepción de los padres sobre las sibilancias y el diagnóstico del médico tras la auscultación (el índice Kappa = 0,7; la odds ratio = 38,33; el intervalo de confi anza al 95%, de 15.8 a 92,8; P< ,001); la sensibilidad (82,8%), la especifi cidad (85,0%), el valor predictivo positivo (81,5%), y el valor predictivo negativo (86,0%) fueron altos. La reproducibilidad a corto plazo de la versión reducida del EISL-CE fue también alta (κ > 0,75). Las preguntas añadidas al EISL-CE reducido mejoraron la