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

Abstract

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.

Figures

Figure 1

Precision Levels across the Positive Affect Measurement Continuum Note: In these figures, the Y-axis represents information function which was then converted to reliability function; X-axis is the IRT-scaled score (theta) where reliability of each score was estimated. The area plotted in blue is mean scores with a reliability ≥ 0.95. The area plotted in yellow represents mean scores with a reliability between 0.9(inclusive) and 0.95 (exclusive). The bottom half of the figure is the participants’ positive affect scores represented in histogram and the upper part of the figure is the information function curve of items, with the cut-off lines for a reliability of 0.95 and 0.90 plotted, respectively.

Figure 2

Precision Levels across the Life Satisfaction Measurement Continuum

Figure 3

Precision Levels across the Meaning & Purpose Measurement Continuum