Construct Validity of the Measurement Tools PH42 and I.ROC12 to Measure Positive Health in a General Population.

'Positive Health' and 'recovery' seem to cover similar multidimensional health perspectives focussing on capabilities instead of incapabilities. The My Positive Health questionnaire and Individual Recovery Outcomes Counter were initially developed as dialogue tools, but nowadays also used as self-reported questionnaires. Structural validity of these dialogue tools was assessed in earlier research resulting in the 42-items Positive Health questionnaire (PH42) and 12-items Individual Recovery Outcomes Counter (I.ROC12). As a next step, we investigated their construct validity. An observational cross-sectional study was conducted in a representative general Dutch population (LISS-panel) determining (1) Coherence between the PH42 and I.ROC12 using correlation coefficients; (2) Convergent validity by testing hypotheses for PH42 and I.ROC12 with external health-related questions using correlation coefficients; (3) Discriminative validity for subgroups gender, age, educational level and healthcare use. (1) Nine out of twelve correlations between PH42 and I.ROC12 factors were substantial (> 0.5). (2) Hypotheses for PH42 and I.ROC12 factors with health-related questions were confirmed for 80% and 75%, respectively. (3) Scores on all factors increased (i.e., better health) from low to high educational level and decreased from no healthcare use to healthcare received from (medical) specialists. Only the factor physical health and functioning showed a continuous decrease in scores with increasing age. Women scored lower only on physical health and functioning. Convergent validity is adequate and discriminative validity is adequate for educational level and healthcare use supporting the conclusion that the PH42 and I.ROC12 are useful instruments to measure Positive Health in a general population.