Firstly basic item analyses were calculated. One psychometric approach used confirmatory and explorative factor analyses. In a next step the item reduction process was carried out on the basis of Item Response Theory Models (IRT).
The result was the KIDSCREEN-27 with five Rasch scaled dimensions: Physical Well-Being, Psychological Well-Being, Autonomy & Parents, Peers & Social Support and School Environment.
The construct validity of the instrument is satisfying; the calculation of a factor analysis explains 56% of the variance and for the reliability of each of the five dimensions Cronbach’s Alpha is >0.70. Analyses to test the construct validity show results in the expected theoretical direction: females show lower HRQOL in the physical and psychological well-being dimensions; older adolescents show lower HRQOL on all dimensions than younger children; children and adolescents with special health care needs display a lower HRQOL in all dimensions in comparison to healthy children and adolescents; and children and adolescents who have spent more than two nights in hospital in the last year display a lower HRQOL in all dimensions in comparison to healthy children and adolescents.
Answering the KIDSCREEN-27 requires only 10-15 minutes. The instrument provides a profile and allows an interpretation of the five dimensions.