PURPOSE: Linking ready-made questionnaires to codes within the International Classification of Functioning, Disability and Health, Children and Youth Version with the intention of using the information statistically for studying mental health problems can pose several challenges. Many of the constructs measured are latent, and therefore, difficult to describe in single codes. The aim of this study was to describe and discuss challenges encountered in this coding process.

MATERIALS AND METHODS: A questionnaire from a Swedish research programme was linked to the International Classification of Functioning, Disability and Health, Children and Youth Version and the agreement was assessed.

RESULTS: Including the original aim of the questionnaire into the coding process was found to be very important for managing the coding of the latent constructs of the items. Items from the International Classification of Functioning, Disability and Health, Children and Youth Version chapters with narrow definitions for example mental functions, were more easily translated to meaningful concepts to code, while broadly defined chapters, such as interactions and relationships, were more difficult.

CONCLUSION: This study stresses the importance of a clear, predefined coding scheme as well as the importance of not relying too heavily on common linking rules, especially in cases when it is not possible to use multiple codes for a single item. Implications for rehabilitation The International Classification of Functioning, Disability and Health, Children and Youth Version, is a useful tool for merging assessment data from several sources when documenting adolescents' mental functioning in different life domains. Measures of mental health are often based on latent constructs, often revealed in the description of the rationale/aim of a measure. The latent construct should be the primary focus in linking information. By mapping latent constructs to the International Classification of Functioning, Disability and Health, Children and Youth Version, users of the classification can capture a broad range of areas relevant to everyday functioning in adolescents with mental health problems. The subjective experience of participation, i.e., the level of subjective involvement, is not possible to code into the International Classification of Functioning, Disability and Health, Children and Youth Version. However, when linking mental health constructs to the International Classification of Functioning, Disability and Health, Children and Youth Version codes, the two dimensions of participation (the being there, and the level of involvement) need to be separated in the linking process. This can be performed by assigning codes focusing on being there as separate from items focusing on the subjective experience of involvement while being there.