The association of loneliness and social isolation with multimorbidity over 14 years in older adults in England: a population-based cohort study

Problem

Previous longitudinal studies have linked multimorbidity to loneliness and social isolation. However, the direction and nature of these associations over time are unclear. We aimed to assess bidirectional associations of multimorbidity with loneliness and social isolation over a 14-year follow-up period in a nationally representative cohort of adults aged ≥ 50 years.

Approach

In this retrospective cohort study, we used seven waves of data (collected between 2004/2005 and 2018/2019) from adults in the English Longitudinal Study of Ageing. Multimorbidity was defined as the presence of ≥2 long-term conditions. Loneliness was measured using the 3-item University of California Los Angeles (UCLA) scale. Social isolation was derived based on cohabitation status, frequency of contact with children, relatives, and friends, and social organisation membership. Cox proportional hazards models, adjusted for social isolation or loneliness, demographic and health behaviour variables, were fitted.

Findings

The study sample consisted of 4256 adults with baseline and follow-up data on loneliness, social isolation, multimorbidity, and covariates. Loneliness was associated with increased risk of incident multimorbidity during follow-up [aHR (95% CI): 1.16 (1.09-1.23)], whereas social isolation was not [aHR (95% CI): 0.95 (0.89-1.01)]. Multimorbidity was associated with increased risk of incident loneliness [aHR (95% CI): 1.14 (1.07-1.21)], but not significantly associated with risk of incident social isolation [aHR (95% CI): 0.97 (0.91-1.03)] during follow-up.

Consequences

Loneliness is independently associated with increased risk of subsequent multimorbidity, and vice versa. Interventions that target loneliness may prevent or delay the development of multimorbidity and also improve wellbeing for people with multimorbidity.