title: Impact of social isolation on behavioral health in elderly: Systematic review.
abstract: OBJECTIVE
  To examine and compare the effects of subjective and objective social isolation on behavioral health in elderly adults.
  
  
  METHODS
  A systematic search of PubMed was performed for original research articles from peer-reviewed journals examining one of the following topics: "Social isolation and sleep disturbance", "social isolation and depression", or "social isolation and fatigue in older adults". Studies were selected following the criteria established based on the aim of this review. Data were extracted from the articles by two independent reviewers. Due to the heterogeneity in study designs and outcome measures of the included studies, qualitative and narrative analyses were conducted.
  
  
  RESULTS
  The set criteria were used to select a total of 16 studies for the review. Of the 16, 13 were cross-sectional studies. The characteristics of study populations were identified as follows. A total of 12 studies randomly selected subjects irrespective of pre-existing health conditions. Consequently, an unspecified number of the study subjects had chronic diseases in the studies compared. In addition, cultural and ethnic backgrounds of studies in this review were diverse, and included subjects living in North America, South America, Asia, Europe, and Oceania. Both subjective and objective types of social isolation increased behavioral symptoms, such as sleep disturbance, depressive symptoms, and fatigue in older adults. Furthermore, a few recent studies reported stronger effects of subjective social isolation than objective social isolation on sleep disturbance and depressive symptoms.
  
  
  CONCLUSIONS
  Social isolation affects behavioral health in older adults. Compared to the objective social isolation, subjective social isolation contributes more significantly to sleep disturbance and depression.
authors.affiliation: Hanbyul Choi, St. George's University School of Medicine, Grenada, West Indies, the North American Correspondent, Great River, NY 11739, United States.
authors.forename: Hanbyul
authors.initials: H
authors.lastname: Choi
authors.affiliation: Hanbyul Choi, St. George's University School of Medicine, Grenada, West Indies, the North American Correspondent, Great River, NY 11739, United States.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Irwin
authors.affiliation: Hanbyul Choi, St. George's University School of Medicine, Grenada, West Indies, the North American Correspondent, Great River, NY 11739, United States.
authors.forename: Hyong Jin
authors.initials: HJ
authors.lastname: Cho
keywords: Depression; Fatigue; Objective social isolation; Older adults; Sleep disturbance; Subjective social isolation; Systematic review