title: Social support and risk-adjusted mortality in a frail older population.
abstract: OBJECTIVE
  The objective of this study was to test the hypothesis that social support is an important predictor of mortality in a frail older population receiving formal long-term care services.
  
  
  METHODS
  The analysis is based on 3138 individuals enrolled in 28 Programs of All-Inclusive Care for the Elderly (PACE). Information about the enrollees is obtained from dataPACE. Semiparametric Cox proportional hazards models are estimated to assess the importance of individual risk factors, program effect, and social support.
  
  
  RESULTS
  The introduction of the social support variables into the mortality model containing the sociodemographic, health needs, and the PACE-site indicator variables results in a significant improvement of the overall model fit. Several social support variables are statistically significant predictors of mortality. Controlling for all participant and caregiver characteristics, participants whose caregiver is a spouse have a significantly lower risk of mortality (hazard ratio = 0.63) compared with those whose caregiver is not a spouse. Furthermore, caregivers' assistance with meals confers a significantly lower risk of morality (hazard ratio = 0.66) compared with no assistance with meals.
  
  
  CONCLUSIONS
  This study shows that certain aspects of informal caregiving are important factors enhancing survival in a population of frail, nursing home-certifiable individuals enrolled in a health program that already provides extensive services, including personal care, chores, and meals. Further research to better differentiate between the affective versus the instrumental dimensions of social support is needed to guide programs on how to balance the use of resources to provide both the necessary formal services and the support for the informal caregivers.
authors.affiliation: Department of Community and Preventive Medicine, University of Rochester School of Medicine, Rochester, NY 14642, USA. Helena_Greener@urmc.rochester.edu
authors.forename: Helena
authors.initials: H
authors.lastname: Temkin-Greener
authors.forename: Alina
authors.initials: A
authors.lastname: Bajorska
authors.forename: Derick R
authors.initials: DR
authors.lastname: Peterson
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Kunitz
authors.forename: Diane
authors.initials: D
authors.lastname: Gross
authors.forename: T Franklin
authors.initials: TF
authors.lastname: Williams
authors.forename: Dana B
authors.initials: DB
authors.lastname: Mukamel
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D017028:Caregivers; D003191:Comprehensive Health Care / Q000706:statistics & numerical data*; D016208:Databases, Factual; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data*; D006299:Health Services for the Aged / Q000458:organization & administration / Q000706:statistics & numerical data*; D006305:Health Status Indicators; D006801:Humans; D008134:Long-Term Care; D008297:Male; D009026:Mortality; D016016:Proportional Hazards Models; D020379:Risk Adjustment; D012944:Social Support; D012959:Socioeconomic Factors; D018454:Spouses; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology