Assessing psychological well-being: self-report instruments for the NIH Toolbox.

OBJECTIVE: Psychological well-being (PWB) has a significant relationship with physical and mental health. As a part of the NIH Toolbox for the Assessment of Neurological and Behavioral Function, we developed self-report item banks and short forms to assess PWB. STUDY DESIGN AND
SETTING: Expert feedback and literature review informed the selection of PWB concepts and the development of item pools for positive affect, life satisfaction, and meaning and purpose. Items were tested with a community-dwelling US Internet panel sample of adults aged 18 and above (N = 552). Classical and item response theory (IRT) approaches were used to evaluate unidimensionality, fit of items to the overall measure, and calibrations of those items, including differential item function (DIF).
RESULTS: IRT-calibrated item banks were produced for positive affect (34 items), life satisfaction (16 items), and meaning and purpose (18 items). Their psychometric properties were supported based on the results of factor analysis, fit statistics, and DIF evaluation. All banks measured the concepts precisely (reliability ≥0.90) for more than 98% of participants.
CONCLUSION: These adult scales and item banks for PWB provide the flexibility, efficiency, and precision necessary to promote future epidemiological, observational, and intervention research on the relationship of PWB with physical and mental health.