Falls and the Social Isolation of Older Adults in the National Health and Aging Trends Study

Thesis (Ph.D.)--University of Washington, 2016-08

University of Washington Abstract Falls and the Social Isolation of Older Adults in the National Health and Aging Trends Study Janet S. Pohl Chair of the Supervisory Committee: Professor Barbara B. Cochrane Department of Family and Child Nursing The de Tornyay Endowed Professor for Healthy Aging Director, de Tornyay Center for Healthy Aging Joint Associate Member, Fred Hutchinson Cancer Research Center Background: Outcomes of social isolation and falls among community-dwelling older adults can be life threatening. While an association between these two gerontological conditions is evident, the nature of that relationship is not well documented. Knowledge is needed regarding how social isolation and falling are associated. Objectives: To report the prevalence of social isolation and the incidence of falls, and to examine the extent to which social isolation at one point in time predicts falls a year later. Methods: This was a cross-sectional, as well as longitudinal secondary analysis of four rounds of data from the National Health and Aging Trends Study (NHATS) including a nationally representative sample of Medicare beneficiaries (round one n = 7,609). In-person interviews with annual re-interviews were conducted in participant residences. Social isolation was operationalized with a domain-inclusive construct based upon the Social Network Index and developed for this study. Falling during the previous year was self-reported. Results: Social isolation prevalence ranged from 19.8 - 21.9%. The incidence of falls ranged from 22.4 - 26.2% across the four rounds. The predicted probability of falling increased with each increase in social isolation construct score. Even after adjusting for age, gender, and education, social isolation significantly predicted falling (OR = 1.08; CI = 1.02–1.14). Adding self-reported general health, depression, and worry about falling to the model weakened the relationship between social isolation and falls (OR = 1.02; CI = 0.96–1.08). Adding the Short Physical Performance Battery, assistive mobility device use, and activities of daily living to the model weakened the relationship further (OR = 0.99; CI = 0.94 –1.04). Conclusions: Social isolation predicted falls in the future. This was potentially explained by the strong relationship between social isolation and physical performance. Interventions targeting both variables could have a strong impact on physical performance and future falls. In addition, “fall-prevention” interventions that specifically target social isolation could incorporate physical performance as a shorter-term and cost effective proxy outcome for falls.