Objectives: To obtain a Spanish version of the Kindl semantically and culturally equivalent to the original German version and to test its psychometric properties.
Material and methods: The methodology used in the adaptation process was based on the forward-backward translation method. To assess the psychometric properties of the Spanish Kindl, the pilot test of the project "Screening for and promotion of HRQL in children and adolescents: a European Public Health perspective (Kidscreen)" it was include in. A classroom was selected for each educational level (8-16 years old) from three schools in Gerona and Barcelona. The Spanish Kindl was administered twice, one week apart. Internal consistency was assessed by computing Cronbach alpha and test-retest stability was assessed using intraclass correlation coefficients (ICC). Analysis of variance was performed according to age, sex, type of school, and self-perceived health status.
Results: Half of the items (12/24) required minor changes during the adaptation process. The response rate was 91 % (n = 447). Internal consistency was acceptable for most domains (alpha range = 0.40-0.88), as was test-retest stability (ICC range = 0.52-0.80). Girls and older teenagers scored worse in most domains (p < 0.01). No differences were found by type of school.
Conclusions: The Spanish version of the Kindl showed adequate reliability and validity coefficients and represents a new HRQL instrument that can be applied in pediatric clinical practice and public health.