Supplementary Material for: The impact of long-term conditions and comorbidity patterns on COVID-19 infection and hospitalisation: a cohort study

Introduction Older adults are more vulnerable to COVID-19 infections; however, little is known about which comorbidity patterns are related to a higher risk of COVID-19 infection. This study investigated the role of long-term conditions or comorbidity patterns on COVID-19 infection and related hospitalisations. Methods This study included 4,428 individuals from Waves 8 (2016−2017) and 9 (2018−2019) of the English Longitudinal Study of Ageing (ELSA) who also participated in the ELSA COVID-19 Substudy in 2020. Comorbidity patterns were identified using an agglomerative hierarchical clustering method. The relationships between comorbidity patterns or long-term conditions and COVID-19 related outcomes were examined using multivariable logistic regression. Results Among a representative sample of community-dwelling older adults in England, those with cardiovascular disease (CVD) and complex comorbidities had an almost double risk of COVID-19 infection (OR=1.87, 95%CI=1.42−2.46) but not of COVID-19 related hospitalisation. A similar pattern was observed for the heterogeneous comorbidities cluster (OR=1.56, 95%CI=1.24−1.96). The individual investigations of long-term conditions with COVID-19 infection highlighted primary associations with CVD (OR=1.46, 95%CI=1.23−1.74), lung diseases (OR=1.40, 95%CI=1.17−1.69), psychiatric conditions (OR=1.40, 95%CI=1.16−1.68), retinopathy/eye diseases (OR=1.39, 95%CI=1.18−1.64), and arthritis (OR=1.27, 95%CI=1.09−1.48). In contrast, metabolic disorders and diagnosed diabetes were not associated with any COVID-19 outcomes. Discussion/Conclusion This study provides novel insights into the comorbidity patterns that are more vulnerable to COVID-19 infections and hospitalisations, highlighting the vulnerability of those with CVD and other complex comorbidities. These findings facilitate crucial new evidence that should be considered for appropriate screening measures and tailored interventions for older adults in the ongoing global outbreak.