Development of a self-assessment tool to address the functioning of community-dwelling older adults in general practice: a validation study of the EFA23 questionnaire.

Background: Multimorbidity is increasingly prevalent among ageing patients, leading to reduced daily functioning. To address the challenges posed by multimorbidity in older adults, a person- and context-centred approach is needed. This study aimed to develop a questionnaire as a self-assessment tool for older adults focusing on functioning in general practice based on the International Classification of Functioning, Disability and Health (ICF).

Methods: A mixed-methods approach was employed in the development and validation of the German EFA23 (Erfassung Funktionaler Gesundheit im Alter - 23 Fragen; Assessing Functional Health in Old Age - 23 questions) questionnaire. Based on an ICF subset developed in a preparatory phase and consensus study, questionnaire items were formulated and tested in a qualitative pretest, followed by a validation study. A workshop with general practitioners (GPs) was held to develop a supplementary manual for GPs on how to interpret the questionnaire results and discuss them with the patients.

Results: A total of 69 items were developed and tested in the qualitative pretest with 15 respondents, resulting in 37 items for the validation study. The validation study, involving 237 older adults, showed the presence of one significant principal component. It demonstrated good internal consistency (Cronbach's alpha = 0.967) and construct validity, showing positive correlations with established assessment tools. Descriptive statistics showed differences between the means of self-assessment by patients and an external GP assessment. The final EFA23 questionnaire consists of 23 items assessing limitations in functioning.

Conclusions: The EFA23 questionnaire can be used as a valid self-assessment instrument to measure functioning in older adults, supporting a person- and context-centred approach in general practice.