Methods
A series of literature searches of the CINAHL, PsycINFO, and Medline databases were conducted, using the key words "social isolation," "social networks," "older adults," "elderly," "belonging," "perceived isolation," "social engagement," "social contacts," and "social integration." Only materials written in English and published in the literature between 1995 and 2010 were included. The decision to focus on only the most recent publications was based on the rapidly changing cultural and societal norms related to social isolation over the past 15 years, which, in turn, have altered the meaning, operationalization, and assessment of social isolation during this time period. Thus, a review of the most current literature is needed to inform the clinical assessment of social isolation. Articles reporting original research focused on older adults, aged 65 years or older, were included. Books, book chapters, and review articles that discussed older adults were also included. In order to be consistent with the definition of social isolation used by Nicholson, (2009), only publications that discussed the following key attributes of social isolation were included: (1) belonging, (2) social contacts, (3) quality of relationships, (4) fulfilling relationships, and/or (5) engagement. Doctoral dissertations, Master's theses, and newspapers were excluded from this literature review, as well as any publications that discussed social isolation in populations other than older adults.