Individuals discharged from hospital after coronavirus disease 2019 (COVID-19) had increased rates of multiorgan dysfunction compared with a matched control group from the general population, according to a study published in The BMJ. In addition, researchers found that the increase in risk was not confined to the elderly and was not uniform across ethnicities.
The findings came from a retrospective cohort study which involved 47,780 individuals (mean age 65, 55% men) hospitalised with COVID-19 and discharged by August 31, 2020 and were matched to controls for personal and clinical characteristics from the general population.
Individuals were followed up from the index date to September 30, 2020 or the date of death (whichever was earlier) for all cause mortality, hospital readmission (or any admission for controls), and diagnoses of respiratory, cardiovascular, metabolic, kidney, and liver diseases.
Over a mean follow-up of 140 days, 14,060 (29.4%) individuals who were discharged from hospital after acute COVID-19 were readmitted and 5,875 (12.3%) died after discharge. The researchers found that these events occurred at rates of 766 (95% confidence interval [CI] 753 to 779) readmissions and 320 (95% CI 312 to 328) deaths per 1,000 person years, which were 3.5 (95% CI 3.4 to 3.6) and 7.7 (95% CI 7.2 to 8.3) times greater, respectively, than those in matched controls.
On the other hand, respiratory disease was diagnosed in 14,140 (29.6%) individuals after discharge, with 6,085 of these being new onset diagnoses, indicating incidence rates of 770 (95% CI 758 to 783) and 539 (525 to 553) per 1000 person years, respectively. Researchers found that the rates were 6.0 (5.7 to 6.2) and 27.3 (24.0 to 31.2) times, respectively, greater than those in controls.
Similarly, diabetes (4.9%), major adverse cardiovascular event (4.8%), chronic kidney disease (1.5%), and chronic liver disease (0.3%) were more frequently diagnosed among individuals discharged after acute COVID-19, occurring at rates of 770 (95% CI 758 to 783), 127 (122 to 132), and 126 (121 to 131) diagnoses per 1,000 person years, respectively. A similar pattern was observed when only new onset diagnoses were considered, but at lower rates of 29 (26 to 32) for diabetes, 66 (62 to 70) for major adverse cardiovascular event, 15 (13 to 17) for chronic kidney disease and 4 (3 to 5) for chronic liver disease diagnoses per 1,000 person years.
Overall, the incidence of diagnoses with major adverse cardiovascular event, chronic liver disease, chronic kidney disease, and diabetes was observed to be 3.0 (2.7 to 3.2), 2.8 (2.0 to 4.0), 1.9 (1.7 to 2.1), and 1.5 (1.4 to 1.6) times, respectively, more frequent among individuals discharged from hospital following COVID-19 compared with those in the matched control group.
Further, the researchers observed that rate ratios comparing patients with COVID-19 and matched controls were greater in individuals aged less than 70 than those aged 70 or more for all outcomes, whereby the largest differences in rate ratios were for death (14.1 [95% CI 11.0 to 18.3] for age <70 years vs 7.7 [7.1 to 8.3] for ≥70) and respiratory disease (10.5 [9.7 to 11.4] for age <70 vs 4.6 [4.3 to 4.8] for ≥70). Meanwhile, ethnic differences in rate ratios were greatest for respiratory disease (11.4 [9.8 to 13.3] for individuals in the non-white group vs 5.2 [5.0 to 5.5] in the white ethnic group).
“Our results are consistent with proposed biological mechanisms associated with respiratory, cardiovascular, metabolic, renal, and hepatic involvement in COVID-19, extending the early evidence base on post-COVID syndrome which has been described as limited and of low quality,” wrote Daniel Ayoubkhani, Office for National Statistics, Newport, United Kingdom, and colleagues.
“Our findings across organ systems suggest that the diagnosis, treatment, and prevention of post-COVID syndrome requires integrated rather than organ or disease specific approaches,” the authors noted. “Urgent research is needed to understand the risk factors for post-covid syndrome so that treatment can be targeted better to demographically and clinically at risk populations.”