In principle, there should be no changes to the KIDSCREEN questionnaires. Changes such as the omission of items or adaptations to a specific sample should generally be viewed critically, since each change alters a stand-ardized instrument and restricts comparability (with other studies, also internationally, and with norm and refer-ence values).
In rare cases, however, omitting items or adjusting to a sample may be appropriate. For example, it happened in the following cases that word changes were made:
It is important that all item changes are consistent so that all items of the questionnaire fit together despite the changes. In the case of publication, changes must be described and discussed, and this must also be considered in comparison with other studies.
Changes to items can lead to a different interpretation, possibly resulting in different constructs being captured than in the validated original questionnaire, (the same applies to use with groups for which the questionnaire has not been validated, e.g. an older sample). As soon as changes of any kind are made, the KIDSCREEN is no longer being used in its original version.
In addition, critical changes, such as the omission of individual items, can lead to the calculation of T-scores (with the syntaxes based on the Rasch person parameters of the norm sample) no longer being displayed.
Use of Individual Scales
During the development of the KIDSCREEN, analyses were conducted that confirmed that the scales of the KID-SCREEN also function well individually. Thus, the questionnaire does not necessarily have to be used or analyzed with all scales. It is therefore also conceivable to use the KIDSCREEN-27 and to supplement it with items from the KIDSCREEN-52 with the aim of capturing, in addition to the 5 scales of the KIDSCREEN-27, certain scales of the KIDSCREEN-52 that are particularly interesting for your study. If, on the other hand, the aim is to reduce the num-ber of items in a large survey, for example, but still to cover the overall construct of health-related quality of life, we recommend switching to a shorter version of the KIDSCREEN.
General Health Item im KIDSCREEN-10
In the KIDSCREEN-10, an eleventh additional item, the so-called "General Health Item" ("In general, how would you say your health is?") is included. This was used, for example, in Bartel et al. (2017) to validate the Kids-CAT. Similarly, it can be used to validate the KIDSCREEN-10. It is important to note, however, that it cannot be used to validate either the KIDSCREEN-27 or the KIDSCREEN-52, as this item is part of both questionnaires.