title: The discrepancy between social isolation and loneliness as a clinically meaningful metric: findings from the Irish and English longitudinal studies of ageing (TILDA and ELSA).
abstract: Scant evidence is available on the discordance between loneliness and social isolation among older adults. We aimed to investigate this discordance and any health implications that it may have.
  
  
  
  Using nationally representative datasets from ageing cohorts in Ireland (TILDA) and England (ELSA), we created a metric of discordance between loneliness and social isolation, to which we refer as Social Asymmetry. This metric was the categorised difference between standardised scores on a scale of loneliness and a scale of social isolation, giving categories of: Concordantly Lonely and Isolated, Discordant: Robust to Loneliness, or Discordant: Susceptible to Loneliness. We used regression and multilevel modelling to identify potential relationships between Social Asymmetry and cognitive outcomes.
  
  
  
  Social Asymmetry predicted cognitive outcomes cross-sectionally and at a two-year follow-up, such that Discordant: Robust to Loneliness individuals were superior performers, but we failed to find evidence for Social Asymmetry as a predictor of cognitive trajectory over time.
  
  
  
  We present a new metric and preliminary evidence of a relationship with clinical outcomes. Further research validating this metric in different populations, and evaluating its relationship with other outcomes, is warranted. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Institute of Neuroscience, Trinity College, Dublin 2, Ireland.|Centre for Public Health, Queen's University Belfast, BT12 6BJ, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: McHugh
authors.affiliation: Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
authors.forename: R A
authors.initials: RA
authors.lastname: Kenny
authors.affiliation: Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
authors.forename: B A
authors.initials: BA
authors.lastname: Lawlor
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, UK.
authors.forename: A
authors.initials: A
authors.lastname: Steptoe
authors.affiliation: Centre for Public Health, Queen's University Belfast, BT12 6BJ, UK.
authors.forename: F
authors.initials: F
authors.lastname: Kee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003071:Cognition / Q000502:physiology; D003430:Cross-Sectional Studies; D004739:England; D005260:Female; D006801:Humans; D007494:Ireland; D008132:Loneliness / Q000523:psychology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012934:Social Isolation / Q000523:psychology*
keywords: ageing; cognitive function; loneliness; social isolation