Toward a representative assessment of competencies for a healthy, physically active lifestyle in the German population: development and validation of a short version of the physical activity-related health competence questionnaire (PAHCO_12)

Representative studies assessing behavior-oriented determinants for physically active lifestyles in the German adult population are lacking due to the absence of validated assessment instruments. Drawing on the physical activity-related health competence (PAHCO) model, the goal of the present study was to develop and evaluate a short version of PAHCO differentiating between the three sub-competencies 'movement competence', 'control competence', and 'self-regulation competence'. In the first step, we reduced the number of items from existing PAHCO-related questionnaires, while adjusting them for a telephone survey mode. In the second step, we validated this 12-item version with N = 3986 adults between 18 and 97 years (57.0 +/- 18.2 years; 52.0% male) within the representative survey "German health Update" (GEDA 2023). We also gathered information about participants' age, gender, education, leisure-time physical activity, and self-reported health. The psychometric analyses revealed satisfactory item statistics. Confirmatory factor analyses suggested a model variant in which two items showed theory-conform parallel loadings on a second sub-competence (comparative fit index [CFI] = 0.924, root mean square error of approximation [RMSEA] = 0.073, standardized root mean square residual [SRMR] = 0.044). The latent sub-competencies were significantly related to physical activity (0.20 <= beta <= 0.27) and health (0.50 <= beta <= 0.65), thus indicating criterion validity. The factor structure turned out to be invariant across age, gender, and educational levels. In summary, this study gained initial insights about the reliability and validity of a 12-item version of the PAHCO questionnaire. We recommend the instrument for use within representative surveys, for initial screening, the reporting of descriptive trends, or secondary outcomes of a trial.