Psychometric Properties of the Negative and Positive Affect Scales (NAPAS) in Patients with Breast Cancer.
Abstract
Background
Breast cancer (BC) has a substantial impact on women's emotional well‑being. This study examined the psychometric properties of the Negative and Positive Affect Scales (NAPAS) to provide validity evidence for their use in women with BC.
Method
We evaluated validity evidence based on internal structure and on relationships with other variables (general health, life satisfaction, self‑esteem and resilience), as well as item analysis, reliability of scale scores and measurement invariance across age groups (N = 202).
Results
Confirmatory factor analysis supported a two‑correlated factor structure, negative affect (NA) and positive affect (PA), χ²(53) = 137.807, CFI = .994, NNFI = .993, RMSEA = .089, SRMR = .067. This structure was invariant between age groups (≤ 50 vs. > 50 years). The homogeneity indices and the reliability of the scores were adequate. PA was positively associated with life satisfaction, self‑esteem and resilience, and negatively associated with general health and its dimensions. NA showed the opposite pattern of associations.
Conclusions
The findings support the use of the NAPAS as a measure of affective well‑being in women with BC. Given its strong associations with mental health indicators, the scale may be useful in clinical settings for assessment and intervention planning.