The Oxford Positive Self Scale: psychometric development of an assessment of cognitions associated with psychological well-being.

Background: Developing, elaborating, and consolidating positive views of the self is a plausible route to increased psychological well-being. We set out to provide an assessment of positive self-beliefs that could be used in research and clinical practice.
Methods: A non-probability online survey was conducted with 2500 UK adults, quota sampled to match the population for age, gender, ethnicity, income, and region. Exploratory factor analysis of a 94-item pool - generated with guidance from people with lived experience of mental health difficulties - was conducted to develop the Oxford Positive Self Scale (OxPos). The item pool was further reduced using regularised structural equation modelling (SEM) before confirmatory factor analysis. Optimal cut-off scores were developed using receiver operating characteristic curves. Additional validations were carried out with two further general population cohorts ( n = 1399; n = 1693).
Results: A 24-item scale was developed with an excellent model fit [robust χ ² = 995.676; df = 246; CFI = 0.956; TLI = 0.951; RMSEA = 0.049 (0.047, 0.052); SRMR = 0.031]. The scale comprises four factors: mastery; strength; enjoyment; and character. SEM indicated that the scale explains 68.6% of variance in psychological well-being. The OxPos score was negatively correlated with depression ( r = -0.49), anxious avoidance ( r = -0.34), paranoia ( r = -0.23), hallucinations ( r = -0.20), and negative self-beliefs ( r = -0.50), and positively correlated with psychological well-being ( r = 0.79), self-esteem ( r = 0.67), and positive social comparison ( r = 0.72). Internal reliability and test-retest reliability were excellent. Cut-offs by age and gender were generated. A short-form was developed, explaining 96% of the full-scale variance.
Conclusions: The new open access scale provides a psychometrically robust assessment of positive cognitions that are strongly connected to psychological well-being.