Psychometric performance of the Quality of Life in Short Stature Youth (QoLISSY) questionnaire in the Netherlands

The European Quality of Life in Short Stature Youth (QoLISSY) questionnaire is a disease-specific instrument assessing quality of life (QoL) in children with short stature from the child and parent perspectives. In order to use the QoLISSY in Dutch samples, a translation process and psychometric testing is needed. Children diagnosed with short stature (8 to 18 years) and their parents were recruited from a Dutch growth clinic. Reliability was assessed using Cronbach's alpha and intraclass correlation coefficients (ICCs). Pearsons' correlations with the generic KIDSCREEN and a confirmatory factor analysis (CFA) were performed to test validity. Scales showed good internal consistency with alpha ranging from 0.80 to 0.94 (child report) and from 0.85 to 0.95 (parent report). Test-retest reliability (ICC) ranged from 0.15 to 0.91 (child report) and from 0.14 to 0.83 (parent report). Correlations with the KIDSCREEN in the mean range indicated criterion validity. The models' goodness of fit was confirmed by CFA results in the Dutch and in comparison with the European sample. Conclusion: The Dutch QoLISSY is a psychometrically reliable and valid short stature-specific QoL measure. It is now available for use in clinical research and practice to evaluate well-being and possible effects of growth hormone treatment and psychological interventions in the Netherlands.