Validation of the Greek version of the Quality of Life in Short Stature Youth (QoLISSY) questionnaire

Background: The Quality of Life in Short Stature Youth (QoLISSY) questionnaire is a condition-specific instrument for measuring the health-related quality of life (HRQoL) in short statured children/adolescents from patients' and parents' perspectives. The aim of this study was to investigate the psychometric properties of the Greek version of the QoLISSY questionnaire. Methods: The original European QoLISSY scales were translated into Greek following the guidelines for linguistic validation and applied to 184 dyads of children 8-18 years old and their parents, as well as to 11 parents of children 4-7 years old in Greece. The field testing responses to the Greek version of QoLISSY were analyzed. Results: The qualitative analysis of the Greek data provided results consistent with the European sample. The subsequent field test showed acceptable internal consistency (Cronbach alpha between 0.67-0.93) and high test-retest reliability (intraclass correlation coefficients [ICC] >= 0.70). Correlations with the generic KIDSCREEN questionnaire indicated good convergent validity. Confirmatory factor analysis (CFA) also yielded acceptable results. Higher HRQoL for taller children suggests that QoLISSY was able to detect significant height-related differences. Conclusions: The Greek version of the QoLISSY questionnaire is psychometrically sound and its use is recommended in further clinical research to ascertain the impact of short stature (SS) and treatments in Greek children/adolescents and families.