Background Social connections have been associated with the risk of several individual chronic conditions, mental health, and biomarkers of health. However, associations between the social connections and multiple long-term conditions (MLTCs) remain unclear. To address this gap, this study aims to assess whether social connections are associated with the number of MLTCs.

Methods A cross-sectional study based on core members of wave 2 (2004-2005) of the English Longitudinal Study of Ageing (ELSA) was conducted. MTLCs were measured using a count of 25 self-reported long-term conditions available in ELSA. Social connections included: a summarised measure of perceived social support from children, spouses, friends and other relatives (scores ranging 0-4); summarised in-person contact from children, spouses, friends and other relatives (‘low’, ‘medium’, and ‘high’); and summarised social participation (‘low’, ‘medium’, ‘high'). The outcome distribution fitted a negative binomial curve. Models were adjusted for confounders sequentially. These models were: the crude association; adjustment for age, sex, and ethnicity; further adjustment for wealth quintile and educational attainment; and further adjustment for household composition and labour force status. Multiple imputation was implemented for missing data which occurred across analysis variables. The sensitivity of results was tested against a stricter criterion for counting conditions – a count of the bodily systems affected by MLTCs. All analysis was conducted using Stata v18.

Results The analytical sample included 7803 participants with a mean of 2.07 conditions, and variance of 3.12. Whilst controlling for all confounders, social support (IRR=0.81, 95%CI=0.77, 0.85, p<0.001), social contact (high vs. low: IRR=0.94, 95%CI=0.90, 0.99, p<0.026), and social participation (high vs. low: IRR=0.91, 95%CI=0.86, 0.97, p<0.001) were found to associate with the number of MLTCs. These results were not sensitive to the use of a count of the number of bodily systems affected by MLTCs.

Conclusion The associations found in this study lend some support to the hypotheses that the presence of social connections may be associated with MLTCs, particularly the presence of social support and social participation. The literature base on this topic is sparce, and by design, this study cannot provide detail on the directionality of findings or whether these associations hold longitudinally. Further research is required to address these limitations and validate the findings here.