A Longitudinal Psychometric Evaluation of a Context-Sensitive Positive Health Questionnaire for Measuring Broad Health in Dutch Adults

IntroductionThe Context-sensitive Positive Health Questionnaire (CPHQ) was developed to measure broad health, grounded in Positive Health and the Capability Approach. Through co-creation with professionals from various domains and citizens, including those with lower socioeconomic position, the instrument was revised into a 28-item version. This study evaluates its psychometric properties. MethodsThis longitudinal study used a stratified sample of Dutch adults to evaluate the psychometric properties of the revised 28-item CPHQ, including factorial and concurrent validity, reliability, and responsiveness. Factorial validity was assessed using Exploratory Factor Analysis, Item Response Theory, and Confirmatory Factor Analysis. Concurrent validity was examined via correlations with existing health and wellbeing measures. Subgroup comparisons were conducted to assess discriminative validity, using independent samples t-tests or ANOVA. Mixed models and Kappa were used to assess test-retest reliability across three timepoints, controlling for life events. ResultsFactor analyses supported an eight-factor structure (mental relaxation, social acceptance, wellbeing, vitality, social support, financial resources, health literacy, mobility) explaining 59.2% of the variance, with good model fit. Internal consistency was acceptable, with composite reliability ranging from 0.59 (health literacy) to 0.90 (financial resources). Concurrent validity was supported by strong correlations with related constructs, particularly in wellbeing, vitality, and social support. Subgroup analyses confirmed hypothesized differences across gender, age, socioeconomic position, and life events, supporting the discriminative validity of the CPHQ2.0. The CPHQ2.0 showed good test-retest reliability (ICCs mostly >0.70), with the total score showing highest stability (ICC=0.88). Kappa values indicated moderate to substantial agreement across timepoints. ConclusionThe CPHQ2.0 is a valid and reliable tool for measuring broad, context-sensitive health, grounded in the Capability Approach and Positive Health concept. Developed with input from diverse stakeholders, it is suitable for use in research, policy, and to target and evaluate health promoting interventions. Future research should assess its sensitivity to detect changes over time following interventions, and explore applicability across settings and populations.