Use with Younger Children (< 8 years)
The KIDSCREEN questionnaires were developed on a sample of children and adolescents aged 8 to 18. For this target group the items were developed, norm values are offered and the T-values were calculated. In our experi-ence, the KIDSCREEN works very well even with 7-year-olds.
In principle, you can also use the KIDSCREEN with 6-year-old children, for example. However, it could be that these relatively young children do not understand some questions or that some questions are inappropriate - de-pending on the sample examined. Slight changes in wording would be conceivable for appropriate adaptation, but these would need to be described and discussed. Please also note that no norm data are available for younger respondent groups and that the T-values were not calculated using 6-year-olds. In such a case, we would advise the independent calculation of sum scores.
We would also like to take this opportunity to briefly introduce the KINDL-R, which is also a very interesting instrument: The KINDL-R is a generic instrument for the assessment of health-related quality of life in children and adolescents between 3 and 17 years of age. The KINDL-R has been translated into numerous languages and used in numerous national and international studies. With 24 items, the KINDL-R is a short, methodologically tested, and flexible instrument. Three versions of the KINDL-R are available for different age or developmental levels. In addition, for each age version of the KINDL-R, a self-report and an external-report version are offered.
Use with young adults (> 18 years)
The use of the KIDSCREEN with older persons is possible in principle. However, it should be noted that norm val-ues are only available for the age group 8-18 years and the T-values are calculated based on the values of the reference sample (8- to 18-year-olds). Accordingly, in such a case we would advise an independent calculation of sum scores.
Alternatively, the SF-36 or the WHOQOL-BREF are most frequently used in adults. Both can be used for purely older survey groups. However, if a mixed-age survey group is involved, these instruments do not provide a directly comparable value to the KIDSCREEN.
If the term "school" is no longer appropriate for an older target group or participants who no longer go to school, it can be expanded to include, for example, the term "vocational school," "university," or even "job."
Use with People with Trisomy 21 (Down Syndrome)
The KIDSCREEN (especially the KIDSCREEN-27) has already been used in some studies with people with trisomy 21 (adults, adolescents, and children). In this particular case, the KIDSCREEN is more suitable for adults than other instruments that are used otherwise, because it is easier to understand. Here are two relevant studies on the subject:
Required Sample Size
The required sample size depends on the research question and the analyses to be performed in the respective study and not on the instrument (KIDSCREEN). Here, an a priori power analysis can provide information. There is no specific guideline value. In general, the larger the sample, the more meaningful the results.
Target Person for the Proxy Questionnaire
The proxy version was designed to be answered by a parent from the child's perspective. Therefore, the target respondents are parents or other guardians/caregivers whose relationship should be close enough to empathize with the child. The answer by teachers, for example, is therefore not helpful under most circumstances.