Measuring Social Isolation Among Older Adults Using Multiple Indicators From the NSHAP Study

Previous research has identified social isolation as a risk factor for physical and mental health problems (e.g., Berkman, 1995; Cacioppo & Hawkley, 2003; Cacioppo, Hughes, Waite, Hawkley, & Thisted, 2006; House, 2001). Socially disconnected and lonely individuals tend to suffer higher rates of morbidity and mortality (Taylor, Repetti, & Seeman, 1997; Thoits, 1995) as well as infection (Cohen, Doyle, Skoner, Rabin, & Gwaltney, 1997; Pressman et al., 2005), depression (Heikkinen & Kauppinen, 2004), and cognitive decline (Wilson et al., 2007). The mere presence of another individual can alleviate stress (Cohen & Williamson, 1991; Thoits), whereas feelings of loneliness may exacerbate the physiological effects of stress, resulting in elevated cortisol levels (Hawkley, Burleson, Berntson, & Cacioppo, 2003; Steptoe, Owen, Kunz-Ebrecht, & Brydon, 2004) and blood pressure (Hawkley et al). The purpose of this article is to demonstrate the development of scales capturing social disconnectedness and perceived isolation using data from the National Social Life, Health, and Aging Project (NSHAP). We use procedures of scale construction to combine multiple indicators of isolation into a scale assessing social disconnectedness and a scale capturing perceived isolation. We then examine the relationship between disconnectedness and perceived isolation and assess their distributions across age, gender, and self-rated health among older adults. Our aim is not to present these scales as definitive measures but to encourage further work toward elucidating the concept, causes, and consequences of social isolation among older adults. Social Isolation Among Older Adults The examination of social isolation among older adults is particularly important for a number of reasons. First, there is some evidence that social isolation may become more common with increasing age. Older adults tend to have smaller social networks (McPherson, Smith-Lovin, & Brashears, 2006) and are more likely to experience feelings of loneliness (Dykstra, van Tilburg, & de Jong Gierveld, 2005). This may be due, in part, to older adults’ experiences of bereavement and their greater likelihood of living alone (Kramarow, 1995; Li & Ferraro, 2005). The correspondence of these conditions has led to the assumption that diminishing social networks result in lower levels of perceived social support and increased loneliness. However, recent research suggests that changes across the life course in social connectedness and satisfaction may be heterogeneous. For example, data from NSHAP indicate that the oldest old have greater participation than the young old (Cornwell, Laumann, & Schumm, 2008), and other research suggests that loneliness may peak in middle age (Carstensen, Isaacowitz, & Charles, 1999). Accordingly, social connectedness, support, and loneliness may not be inextricably linked, especially among older adults. In the face of shrinking social networks, older adults may develop closer relationships and shift expectations so that decreasing connectedness does not necessarily result in the perception of isolation (Lang & Carstensen, 1994; Schnittker, 2007). Finally, to the extent that social isolation is associated with worse health, it may pose a particularly severe risk for older adults. Older adults are more likely to experience bereavement and develop health problems, both of which may increase their need for social support and companionship. As a result, social isolation may be particularly deleterious for older adults. Indeed, research indicates that older adults who experience one or another aspect of isolation have been found to be at greater risk for all-cause mortality, increased morbidity, depression, and cognitive decline (Brummett et al., 2001; Cacioppo & Hawkley, 2003; House, Landis, & Umberson, 1988; Sherbourne, Meredith, Rogers, & Ware, 1992; Tomaka, Thompson, & Palacios, 2006). Measuring Social Isolation The variety of indicators of isolation and loneliness used across research in different disciplines is both a blessing and a curse. This work has captured an enormous number of facets of individuals’ everyday social worlds. Indicators of isolation in previous research include living alone (Dean, Kolody, Wood, & Matt, 1992; Hughes & Gove, 1981; Waite & Hughes, 1999), being unmarried (Lillard & Waite, 1995; Ross, 1995), having a small social network (Berkman & Syme, 1979; Seeman, Berkman, Blazer, & Rowe, 1994), infrequent contact with network members (Brummett et al., 2001), a lack of social network diversity (Barefoot, Gronbaek, Jensen, Schnohr, & Prescott, 2005), a perceived lack of social support (Blazer, 1982; Krause, 1987; Lin, Ye, & Ensel, 1999; Wethington & Kessler, 1986), low participation in social activities (Benjamins, 2004; Ellison & George, 1994; Thoits & Hewitt, 2001), emotionally distant relationships (Uno, Uchino, & Smith, 2002), and feelings of loneliness or not belonging (Cacioppo et al., 2006; Hawkley et al., 2003). However, most of this work has been limited to the examination of only one or two indicators of isolation (or connectedness), or it has focused on only one conceptual area, such as support, participation, or loneliness. As a result, it is difficult to discern whether multiple features of isolation might combine to create particularly severe situations of social isolation among the oldest old. It is also unclear whether feelings of loneliness and a lack of social support do, in fact, follow the loss of social network ties or if more subjective appraisals of isolation are separate from objective features of isolation. In efforts to consolidate multiple measures of social isolation, several authors have previously identified central components of isolation. For example, van Baarsen, Snijders, Smit, and van Duijn (2001) distinguish between social loneliness, as the lack of integration and companionship, and emotional loneliness, as the lack of an attachment figure. De Jong Gierveld and Hagestad (2006) similarly contrast isolation (as the opposite of integration) with loneliness (as the opposite of embeddedness). Following these distinctions and building from the disciplinary approaches of both sociology and psychology, we suggest two distinct aspects of social isolation. Social disconnectedness can be characterized by a lack of contact with others and indicated by situational factors, such as a small social network, infrequent interaction, and a lack of participation in social activities and groups. Perceived isolation, on the other hand, can be characterized by the subjective experience of a shortfall in one’s social resources such as companionship and support. Individuals who are socially disconnected may have small social networks, interact with network members infrequently, and rarely participate in social activities. On the other hand, individuals who perceive themselves to be isolated may report feelings of loneliness and perceive a lack of social support from friends and family members. Social disconnectedness and perceived isolation are related, but we hypothesize that they are distinct. Some research indicates, for example, that feelings of loneliness are responsive to changes in network size, but other findings indicate only a modest correlation between disconnectedness and perceived isolation (Hawkley et al., 2003; Hughes, Waite, Hawkley, & Cacioppo, 2004; Schnittker, 2007). Although physical separation from others and feelings of loneliness may go hand-in-hand for some individuals, infrequent social interaction may not lead to feelings of loneliness for others. Alternatively, people who are socially active and embedded within an expansive social network may feel socially isolated if their relationships lack emotional closeness and support.