Compare methods

	Social Isolation Index	UCLA Loneliness Scale
Field	Social Gerontology	Social Psychology
Family	Process / pipeline	Process / pipeline
Year of origin	2009	1978
Originator	Erin York Cornwell & Linda J. Waite	Daniel Russell
Type	Composite index pipeline distinguishing structural and perceived social isolation	Subjective loneliness assessment scale
Seminal source	Cornwell, E. Y., & Waite, L. J. (2009). Social disconnectedness, perceived isolation, and health among older adults. Journal of Health and Social Behavior, 50(1), 31-48.	Russell, D. W. (1996). UCLA Loneliness Scale (Version 3): Reliability, validity, and factor structure. Journal of Personality Assessment, 66(1), 20–40.
Aliases	Social Disconnectedness and Perceived Isolation Index, Cornwell-Waite Isolation Index, Structural and Perceived Isolation Scales, Composite Social Isolation Measure	UCLA LS, UCLA Loneliness Scale, Russell Loneliness Scale
Related	3	3
Summary	The Social Isolation Index, in the form developed by Erin York Cornwell and Linda Waite in 2009, is a survey-based measurement pipeline that separates the objective and subjective sides of social isolation among older adults. Cornwell and Waite argued that being structurally cut off from social contact, which they called social disconnectedness, is conceptually distinct from feeling isolated or unsupported, which they called perceived isolation, and that the two should be measured separately rather than merged. The disconnectedness scale combines indicators such as small social network size, infrequent contact and social participation, and few social ties, while the perceived-isolation scale combines feelings of loneliness, a perceived lack of support, and a sense of being isolated. Each set of indicators is standardized and summed into its own scale, and the two scales are then entered jointly into models of health outcomes. Their analysis showed that disconnectedness and perceived isolation are correlated but have partly distinct associations with physical and mental health. The approach has become a template for studying social isolation as a multidimensional construct in ageing research.	The UCLA Loneliness Scale is a widely used instrument for measuring subjective feelings of loneliness and social isolation. Developed by Daniel Russell in the late 1970s, the scale measures the discrepancy between desired and actual social relationships. The UCLA LS has become the gold standard in loneliness research and is used across clinical, epidemiological, and social psychology studies worldwide.