COVID-19 - exploring the implications of long-term condition type and extent of multimorbidity on years of life lost: a modelling study.

Background: COVID-19 is responsible for increasing deaths globally. Estimates focused on numbers of deaths, do not quantify potential years of life lost (YLL) through COVID-19.  As most people dying with COVID-19 are older with underlying long-term conditions (LTCs), some speculate that YLL are low. We aim to estimate YLL attributable to COVID-19, before and after adjustment for number/type of LTCs. Methods: We first estimated YLL from COVID-19 using WHO life tables, based on published age/sex data from COVID-19 deaths in Italy. We then used aggregate data on number/type of LTCs inform a Bayesian model for likely combinations of LTCs among people dying with COVID-19. From these, we used routine UK healthcare data from Scotland and Wales to estimate life expectancy based on age/sex/ combinations of LTCs using Gompertz models. We then calculated YLL based on age, sex, type of LTCs and multimorbidity count. Results: Using the standard WHO life tables, YLL per COVID-19 death was 14 for men and 12 for women. After adjustment for number and type of LTCs, the mean YLL was slightly lower, but remained high (11.6 and 9.4 years for man and women, respectively). The number and type of LTCs led to wide variability in the estimated YLL at a given age (e.g. at ≥80 years, YLL was >10 years for people with 0 LTCs, and <3 years for people with ≥6). Conclusions: Deaths from COVID-19 represent a substantial burden in terms of per-person YLL, more than a decade, even after adjusting for the typical number and type of LTCs found in people dying of COVID-19. The extent of multimorbidity heavily influences the estimated YLL at a given age. More comprehensive and standardised collection of data on LTCs is needed to better understand and quantify the global burden of COVID-19 and to guide policy-making and interventions.