Psychometric analysis of the short form UCLA Loneliness Scale (ULS-8) in people with Parkinson's disease.

BACKGROUND

Loneliness has recently been shown to be associated with worse motor and non-motor scores and Quality of Life (QOL) in people with Parkinson's disease (PWP), although a validated measure for use in this population has not yet been validated.

GOAL

The goal of this study was to assess the factor structure and structural validity of the UCLA Loneliness Scale (ULS-8) in a sample of PWP.

METHODS

The dataset was split randomly into two halves: the first for exploratory factor analysis (EFA) using bivariate correlation, the Kaiser-Meyer-Olkin (KMO) test, and Bartlett's test of sphericity, and the second for confirmatory factor analysis (CFA) to validate the factor structure identified by EFA.

RESULTS

Exploratory factor analysis (EFA) on the first subset of 384 subjects identified a clear two-factor structure, supported by strong KMO (.90) and Bartlett's test of sphericity (χ2 = 94.234, df = 6, p < .01) results, suggesting the data were appropriate for factor analysis. Confirmatory factor analysis (CFA) on the second subset confirmed the two-factor structure with satisfactory model fit indices, validating the structural integrity of the scale. Correlation results indicated that one item ("I am an outgoing person") should be excluded from the analysis, resulting in a 7-item instrument.

DISCUSSION/CONCLUSION: The results of this psychometric validation study confirm the reliability and preliminary validity of a revised 7-item version of the ULS-8 scale for assessing loneliness in PWP. This study provides evidence for its utility in both clinical and research settings to assess and address loneliness effectively.