In a recently published study, Dr BMC MedicineThe researchers examined associations between functional and structural components of social connectedness and all-cause and cardiovascular disease (CVD) mortality using data from the United Kingdom (UK) Biobank.
They examined independent and combined associations to understand how these social factors interact.
Study: Longitudinal associations between paternal mental health and child behavior and cognition in middle childhood. Image credit: antoniodiaz/Shutterstock.com
Between 9.2 and 14.4% of the world’s population experience loneliness and 25% of adults may be socially isolated; These statistics indicate the extent to which lack of social connection increases anxiety
Social connectedness has interrelated structural (eg, frequency of social visits with family and friends) and functional (eg, perceived loneliness) components, and a deficit in even one can increase the risk of all-cause and CVD mortality.
Previous studies have shown independent associations between a functional or structural social connection component and a higher risk of all-cause mortality using a single-item measure.
On the other hand, some studies have used composite scales, such as the Berkman-Sime Social Network Index, to measure the structural components of social connections.
A meta-analysis of prospective studies examining and even quantifying associations between functional or structural social connections and all-cause mortality.
However, the observed effect sizes represent the overall effect of different measures, showing no accountability for the strength of each measure and its impact on health. These analyses, however, failed to identify potential synergistic interactions between functional and structural components.
Several processes come into play when testing this association; For example, reverse functioning, where a disability prevents people from forming or sustaining relationships. However, it remains unclear which social connection components are associated with mortality, whether they vary with assessment methods, or how direct and indirect factors influence them.
Poor immune function and neurodevelopmental impairment are some of the factors that directly influence this association, while substance abuse and poor mental or physical health influence this association indirectly.
Overall, there is a lack of research examining the various components of social connections in a dataset that describes all of their effects, including independent, additive, and multiplicative effects.
Insights into the health effects of different social connection components and their interactions can help guide policies to enhance social connection and improve health through targeted interventions.
About the study
In the current study, researchers invited 502,536 UK biobank participants enrolled between 2006 and 2010 to visit one of 22 assessment centers in England, Scotland or Wales.
They collected their baseline data, including their physical measurements and additional information collected using a questionnaire and an interview conducted by a trained healthcare professional.
The team examined baseline data and all-cause and CVD mortality (adverse health outcomes), where International Classification of Diseases (ICD) 10th revision codes I05 through I99, G45, G46, and Z86.7 defined CVD mortality.
Furthermore, they measured the ability to confide in their close person and feelings of loneliness (two functional components) and the frequency of friends and family visits, weekly group activities and living alone (three structural components).
Study covariates included self-reported gender, ethnicity, smoking status, alcohol intake, physical activity level, month of assessment, and 43 long-term health conditions. In addition, they included body mass index (BMI) as a continuous measure and postcode of residence at recruitment as a continuous variable.
The researchers used a Cox proportional hazards model (time-to-event analysis) to examine the relationship between social connections and mortality for all participants.
Given the highly correlated measures of social connectedness and covariates, they detected potential multicollinearity using the generalized variance inflation factor (GVIF) for all study variables.
They then examined the relationship between each functional component measure and adverse health outcomes separately, adjusting for all confounders.
They also investigated the combined association of these measures and their interaction with regard to adverse health outcomes. They created a new dichotomous ‘functional isolation’ variable and examined its relationship with mortality.
Structural component analysis examines the relationship between each structural component measure and adverse health outcomes separately. Finally, researchers have also investigated the combined effects of functional and structural factors.
The main analysis included 458,146 UK biobank participants with a mean age of 56.5 years. Of these, 95.5% were of white ethnicity and 54.7% were women. CVD accounted for 1.1% of a total of 33,135 deaths during a mean follow-up of 12.6 years.
In general, participants reporting fewer social connections were more likely to engage in unhealthy practices (eg, smoking), be socioeconomically disadvantaged, and belong to a minority ethnicity. They had higher BMI and more long-term health conditions.
Participants showed a strong association with higher all-cause and CVD mortality, with their respective hazard ratios (HRs) of 1.07 and 1.17 and 1.06 and 1.08 for having a functional system of social connections, inability to trust others, and feeling lonely.
Combining these measures resulted in a new dichotomous functional isolation variable, which showed an association with higher all-cause and CVD mortality with HRs of 1.08 and 1.16, respectively.
Fully adjusted models of the association between frequency of visiting friends and family and all-cause mortality showed that visiting friends and family less than once per month was associated with increased risk of all-cause mortality, with HRs of once every three months and never of 1.11 and 1.39, respectively.
The pattern was similar for CVD mortality, but the associations were stronger and had wider confidence intervals (CIs).
Visiting intimates once per month provides the greatest benefit, and once validated in other datasets, this may help identify which measures of social connectedness would be most beneficial to target with interventions.
Similarly, not engaging in weekly group activities and living alone increased the risk of all-cause and CVD mortality, HRs: 1.13 and 1.10 and 1.25 and 1.48, compared with those who engaged in weekly group activities and lived with at least one partner. .
Combined association models also showed that fewer friends and family visits increased the risk of all-cause mortality, regardless of whether participants engaged in a weekly group activity.
Furthermore, examining the combined associations between the two functional component measures and all-cause mortality when structural isolation was present showed that being unable to trust was associated with higher all-cause mortality regardless of feelings of loneliness (HRs: 1.41 vs. 1.38).
However, in the absence of structural isolation, this association showed a greater difference between reporting feeling lonely and not (HR 1.16 vs. 1.07), highlighting the complexity and possible hierarchy of social connection components, especially for those who experienced numerous types of social Disconnected.
Thus, it is important to consider multiple mechanisms when exploring the combined effects of all social factors on health outcomes.
For example, the authors observed that a lack of visits from friends and family and living alone reduced the risk of death associated with regular group activities.
Exploring this concept in other datasets may highlight intervention targets for the most marginalized individuals in society.
To date, there is no standardized measure for social connectedness. However, independent associations in this study point to further work to ascertain whether living alone may represent a simplified measure of risk and mortality of living alone and its interaction with friends and family visits and weekly group activities and examining social connections.
Those who live alone and show additional contemporary markers of structural isolation represent a population that may benefit from targeted support. Thus, policies and interventions that address various social connectivity components should target such high-risk groups.
Future studies should investigate the role of potential mediators (eg, mental health problems) to elucidate the mechanistic pathways through which social disconnection leads to mortality.