Adaptation and interobserver agreement in a Danish translation of the Clinical Frailty Scale Questionnaire

INTRODUCTION: The Clinical Frailty Scale (CFS) assesses frailty in older adults. Although the scale has been translated into Danish, the accompanying questionnaire and classification tree have not. The questionnaire includes seven questions about basic and instrumental activities of daily living, chronic conditions, self-rated health, energy level and physical activity, guiding the respondent to a CFS level through the classification tree. This study translated and cross-culturally adapted the CFS questionnaire and classification tree into Danish and assessed the interobserver agreement in a hospital setting.

METHODS: The Danish version of the CFS short questionnaire and classification tree was developed in five stages: forward translations, synthesis, back-translation, review by a committee panel and pre-testing, followed by comprehension interviews and an interobserver agreement study.

RESULTS: The back-translations closely matched the original. Minor discrepancies in contextual and idiomatic expressions were resolved through committee review. Pre-test confirmed comprehension, requiring no further changes. The kappa for interobserver agreement was 0.78.

CONCLUSIONS: The CFS questionnaire and classification tree were translated and cross-culturally adapted into Danish and are attached to this paper. The interobserver agreement achieved is considered acceptable for applying the CFS in emergency and orthopaedic departments.

FUNDING: None.

TRIAL REGISTRATION: Not relevant.