The aim was to analyse the performance of the pilot questionnaire in a representative sample of the target population, to refine the scale structure, and to assess the retest-reliability as well as the construct validity of the KIDSCREEN instrument.
The aim of the KIDSCREEN project was not only to develop an instrument to assess HRQoL in children and adolescents and their parents, but to describe the relationship between the KIDSCREEN questionnaire and other relevant determinants. Besides age and gender, relevant determinants of HRQoL mentioned repeatedly in the literature are the health status of children and adolescents, children’s and adolescents’ mental health, the parent-child relationship and social support, familial socio-economic status and the parents’ health status. Children’s and adolescents’ HRQoL has an impact on their risk behaviour and health service use. In the KIDSCREEN survey the above mentioned determinants were included to test the relationship between the determinants and the KIDSCREEN questionnaire and to validate the questionnaire.
Instruments and Questionnaires included in the KIDSCREEN
Survey Relevant determinants and variables were included in the KIDSCREEN survey for the sample description and to validate the KIDSCREEN instruments:
- SES (socio-demographic and socio-economic status),
- BMI (weight, height),
- health status (CSHCN screener),
- psychosomatic complaints (HBSC),
- mental health (SDQ Strength and Difficulties Questionnaire),
- risk behaviour (smoking, alcohol),
- health services utilisation (EUROHIS),
- parent-child relationship (social support: SAS-Social Support Scale,
- Oslo 3-item Social Support Scale),
- emotional well-being (items from the CHQ, KINDL, SF-36),
- DISABKIDS generic, chronic disability items,
- YQOL (Youth Quality of Life Instrument),
- CHIP (Child Health and Illness Profile),
- CHQ PF 28 (Child Health Questionnaire Parent Form),
- generic questionnaire (country specific, e.g. KINDL included in AT, CH, DE; Cantril's Ladder in CZ, HU, PL),
- parental health (SF12 Short Form).
Sampling and Administration
In the survey phase of the KIDSCREEN project, national representative surveys were conducted in order to obtain reference scores of health-related quality of life for each participating country. Two approaches of survey selection were followed in the KIDSCREEN study in order to obtain surveys: six countries (AT, CH, DE, ES, FR, NL) centrally organised the sampling, monitoring and evaluation through phone contacts; five countries (EL, HU, IE, PL, SE) did it through schools and one country (CZ) through households. In the UK telephone and school sampling methods were combined. In Ireland a preliminary study in two Health Board areas was conducted and a national representative survey has been proposed. For this reason, the survey data for Ireland has not yet been analysed. In both sampling methods - the combination of telephone and mail survey and school sampling - a second administration of the questionnaire to a subsample was carried out two to four weeks after the first survey in order to check test-retest reliability.
The KIDSCREEN field survey was conducted in an overall sample of 21,804 children and adolescents 8-18 years old. The distribution by sex and age of children was quite similar to the reference population. In comparison to the reference population from Eurostat, the KIDSCREEN’s mothers and fathers had higher level of education. Similarly, compared to refusers, survey participants declared more frequently to have high educational level, better general perceived health, to be married and to live in cities. These results coincide with other European studies.
The survey results provided the reference data reported in the KIDSCREEN manual.