Associations between inflammatory bowel disease, social isolation, and mortality: evidence from a longitudinal cohort study

Background: Social well-being of patients with inflammatory bowel disease (IBD) is garnering increased attention; however, the impact of social isolation remained poorly understood. Objectives: We investigated the joint association of social isolation and IBD with premature deaths to articulate the profound impact of social isolation in IBD prognosis. Design: Longitudinal cohort study. Methods: We leveraged data of 486,014 participants from UK Biobank (including 5791 with IBD), the mean follow-up was 11.84 years. Diagnoses of IBD and its subtypes of Crohn's disease (CD) and ulcerative colitis were confirmed with the combination of self-reporting, primary care, and hospital admission data. Social isolation was measured by the frequency of meeting family/friends, leisure and social activity, and communal/solitary living. Mortality was ascertained through data linkage with national death registries. Multivariable Cox regression models were conducted to estimate hazard ratio (HR) and 95% confidence interval (CI). Results: Comparing non-isolated non-IBD population, the HRs of mortality in patients with IBD who were socially isolated or not were 2.06 (95% CI: 1.69, 2.51) and 1.33 (95% CI: 1.21, 1.45), respectively. The excess risk of death was observed in socially isolated patients with IBD (HR = 1.69, 95% CI: 1.36, 2.11), particularly among patients with CD (HR = 2.06, 95% CI: 1.48, 2.87) than their non-isolated counterparts. Data from subgroup and sensitivity analyses were consistent with those from the primary analysis. Conclusion: Socially isolated patients with IBD especially CD increases the risk of premature death. Preventing social isolation might be a promising approach to improve IBD prognosis. Plain language summary Social isolation as a risk factor to excess mortality in patients with IBD: findings from a longitudinal cohort study Social isolation is prevalent in individuals with inflammatory bowel disease (IBD); however, its potential health impact on IBD prognosis has not been quantitatively well examined. In this study, we explored the association between social isolation and subsequent death, with the focus on patients with IBD. We leveraged data of 486,014 participants (including 5791 with IBD) from UK Biobank. We measured social isolation by the frequency of meeting family/friends, leisure and social activity, and communal/solitary living. We ascertained patients with IBD and mortality by self-report data and data linkage with primary care, hospital, and national death registry. Participants were followed up for a mean of 11.84 years. Comparing non-isolated non-IBD population, we found that patients with IBD who were deemed as socially isolated or not were associated with a 2.06-fold (1.69-2.51) and 1.33-fold (1.21-1.45) risk of death, respectively. Furthermore, we revealed that socially isolated patients with IBD and subtype Crohn's disease (CD) had 69% (36-111%) and 106% (48-187%) increased risk of premature death compared with their non-isolated counterparts, respectively. Social isolation merits attention in IBD care and management. Patients with IBD, especially CD, are more likely to be affected when socially isolated. Targeted social support strategies ought to be devised to improve IBD prognosis.