Spanish Version of Teenagers' Quality of Life (T-QoL) for Adolescents with Skin Diseases: Translation, Cultural Adaptation and Validation

Abstract

Background: Teenagers' Quality of Life (T-QoL) is an age-specific measure to assess QoL of teenagers suffering from different skin diseases. A validated Spanish language version is lacking. We present the translation, cultural adaptation and validation of the T-QoL into Spanish.

Methods: A prospective study with 133 patients (between 12 and 19 years old), attended at the dermatology department of Toledo University Hospital, Spain (September 2019-May 2020), was carried out for the validation study. The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines were used for the translation and cultural adaptation. We evaluated the convergent validity with the Dermatology Life Quality Index (DLQI), the Children's Dermatology Life Quality Index (CDLQI) and with a Global Question (GQ) on self-assessed disease severity. We also analysed internal consistency and reliability of the T-QoL tool and confirmed its structure with a factor analysis.

Results: Global T-QoL scores significantly correlated with the DLQI and the CDLQI (r = 0.75) and with the GQ (r = 0.63). The confirmatory factor analysis showed optimal fit for the bi-factor model and an adequate fit for the correlated three-factor model. Reliability indicators were high (Cronbach's α = 0.89; Guttman's Lambda 6 index = 0.91; Omega ω = 0.91) and test-retest showed a high stability (ICC = 0.85). The results were consistent with those found by the authors of the original test.

Conclusion: Our Spanish version of the T-QoL tool is valid and reliable to assess QoL of Spanish-speaking adolescents with skin diseases.

Keywords: Adolescentes; Adolescents; Calidad de vida; Cuestionario; Dermatology; Dermatología; Investigación cualitativa; Qualitative research; Quality of life; Questionnaire.