Socio-economic inequalities in life expectancy of older adults with and without multimorbidity: a record linkage study of 1.1 million people in England

Background: Age of onset of multimorbidity and its prevalence are well documented. However, its contribution to inequalities in life expectancy has yet to be quantified. Methods: A cohort of 1.1 million English people aged 45 and older were followed up from 2001–2010. Multimorbidity was defined as having two or more of 30 major chronic diseases. Multi-state models were used to estimate years spent healthy and with multimorbidity, stratified by sex, smoking status and quintiles of smallarea deprivation. Results: Unequal rates of multimorbidity onset and subsequent survival contributed to higher life expectancy at age 65 for the least (Q1) compared to most deprived (Q5): there was a two-year gap in healthy life expectancy for men (Q1: 7.7 years [95% CI: 6.4–8.5] vs Q5: 5.4 [4.4–6.0]) and a three-year gap for women (Q1: 8.6 [7.5– 9.4] vs Q5: 5.9 [4.8–6.4]); a one-year gap in life expectancy with multimorbidity for men (Q1: 10.4 [9.9–11.2] vs Q5: 9.1 [8.7–9.6]) but none for women (Q1: 11.6 [11.1–12.4] vs Q5: 11.5 [11.1–12.2]). Inequalities were attenuated but not fully attributable to socioeconomic differences in smoking prevalence: multimorbidity onset was latest for never smokers, and subsequent survival was longer for never and ex smokers. Conclusions: The association between social disadvantage and multimorbidity is complex. By quantifying sociodemographic and smoking-related contributions to multimorbidity onset and subsequent survival, we provide evidence for more equitable allocation of prevention and health care resources to meet local needs.