Validity and reliability of the University of California and Los Angeles Loneliness Scale in individuals with chronic obstructive pulmonary disease

The psychometric properties of loneliness measures have not been reported in individuals with chronic obstructive pulmonary disease (COPD). This study aimed to assess the validity and reliability of the University of California and Los Angeles Loneliness Scale (UCLA-LS) version 3 for use in this population. The UCLA-LS was administered at baseline and again after 1 to 2 weeks for test-retest reliability assessment. Intraclass Correlation Coefficient (ICC) was used to assess reliability and estimate minimal detectable change (MDC). Construct validity was established by assessing known groups, and convergent and divergent validity. Of the 47 individuals included in this study, 40 persons (87%) reported moderate to high loneliness levels. The UCLA-LS discriminated (p < 0.03) between groups based on marital status, with higher loneliness levels for single (mean difference [MD] = 8 points) and widowed (MD = 7 points) compared to married individuals. The scale had moderate to strong associations with measures of depression (ρ = 0.69-0.72; p < 0.001), anxiety (ρ = 0.46-0.52; p < 0.03), and quality of life (Chronic respiratory questionnaire [CRQ]-Fatigue: ρ = −0.51-−0.53; CRQ-Emotional function: ρ = −0.59-−0.57; CRQ-Mastery: ρ = −0.43-−0.46; p < 0.003). The UCLA-LS showed excellent test-retest reliability with ICC values of 0.96. To detect a change in version 3 UCLA-LS, the MDC score should equal or exceed 7.8 points. UCLA-LS demonstrated excellent known groups, convergent and divergent validity, and test-retest reliability. These findings may help improve the interpretability of loneliness levels in individuals with COPD.