The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogen, has claimed the lives of over 2.79 million people worldwide. However, the long-term effects of the virus on human health and lifespan are less well known.
A new study, which appeared in the British Medical Journal, reports on a retrospective study to examine the incidence and risk factors for ‘long COVID-19’, the term used to describe the long-term effects of COVID-19 on affected individuals.
According to the National Institute for Health and Care Excellence (NICE), long COVID, also known as ‘post-COVID-19 syndrome’, comprises “signs and symptoms that develop during or after an infection consistent with covid-19 which continue for more than 12 weeks and are not explained by an alternative diagnosis.” Beyond six weeks, in fact, it recommends that the patient be referred for assessment.
The current study aimed to estimate the excess number of illnesses persisting in recovered COVID-19 individuals, using national electronic health records and death registration records.
The study included patient data from the General Practice Extraction Service Data for Pandemic Planning and Research (GDPPR) up to 30 September 2020, and Hospital Episode Statistics Admitted Patient Care records for England up to 31 August 2020, besides death registrations from the Office for National Statistics, for deaths up to September 30, 2020.
All participants were hospitalized with COVID-19 between January 1 to August 31, 2020. Information on comorbidities such as respiratory disease, cardiovascular disease, diabetes and chronic kidney disease was collected. Controls were also matched to the patients.
The study thus included about 48,000 patients, of whom about one in ten required intensive care unit admission. They were followed up for a mean of 140 days and 150 days, for cases and controls, respectively. The mean age for cases was 65 years, and about 55% were men.
Risk factors for COVID-19 included being male, aged 50 years or above, inidicators of socioeconomic deprivation, a history of smoking, and an excessive body mass index. The presence of pre-existing illnesses also predisposes one to COVID-19.
What were the results?
The findings show that between one in three and four individuals hospitalized with COVID-19 required a repeat admission, while a little over one in ten died after being discharged. This corresponds to a rate of about 770 and 320 readmissions and deaths, respectively, per 1,000 person-years.
These rates are 3.5 and 7.7 times higher in cases relative to controls.
Respiratory disease was diagnosed in over 14,000 patients, comprising about 30% of the total, and a little less than half of these lung conditions were newly diagnosed. This yields a rate of 770 and 540 per 1,000 person-years, which is six- and 27-fold greater than that seen in controls.
The rates of major comorbidities were between 1.5 to 3 times greater in cases than in controls. Even after being discharged from the hospital, the rates of death, readmission and multiorgan damage remained much higher in cases.
Among those who required ICU care, the rates of respiratory disease and diabetes were higher after discharge, but they had lower mortality, readmission and major adverse cardiovascular events (MACE) than other hospitalized COVID-19 patients.
Age plays a role in the rates of death, readmission and organ dysfunction, all of which were higher in hospitalized cases aged 70 or more, relative to younger patients. Compared to controls, however, cases below 70 showed a higher increase in rates than older patients.
The increases were observed to be highest for death, which was 14 times more common in patients below 70 years vs. eight times higher for those aged 70 or more, compared to controls. Respiratory disease rates went up 11-fold and 5-fold, respectively, relative to controls.
Most of these rates were lower in Whites, except for diabetes. The highest difference in the rates was seen with respiratory disease, at 11-fold higher rates in non-Whites compared to 5-fold in the White group.
What are the implications?
The study shows that hospitalization with COVID-19 is linked to a higher risk of readmission and of death after discharge, compared to non-COVID-19 individuals of the same ethnicity, age and sex.
The rates of multiorgan dysfunction were markedly higher in people with COVID-19 compared to controls, indicating that the virus attacks tissues outside the lungs, causing damage.
The most commonly observed diseases were diabetes and MACE, both pre-existing and new cases.
Finally, those aged 70 years or above were at a greater absolute risk of death, readmission and multiorgan damage, compared to those who were younger, and for Whites compared to Black or other ethnicities. When compared to controls, those younger than 70, and minority-origin individuals, showed higher relative increases in these rates.
Those who were in the ICU before discharge showed higher risks of death and readmission. Perhaps this is because those not admitted (due to advanced age, multiple illnesses, or irreversible progressive organ damage) were more severely ill but were not admitted to the ICU because of the local hospital codes.
It is noteworthy that 53% of those admitted to the ICU emerged alive from hospital, but 63% of those were admitted to the ICU. This might be a form of survivorship bias, suggest the researchers.
The rates of readmission and death in this study agree with earlier reports, but extends their findings to reflect the occurrence of multiorgan dysfunction after discharge in a significant proportion of hospitalized COVID-19 patients.
The UK has been hit hard by the virus, with over three million COVID-19 cases so far. Many more cases have undoubtedly been missed because they went untested. The findings of this study indicate that a large number of post-COVID syndrome cases can be expected to rise, putting a heavy burden on healthcare infrastructure and staff.
Again, this study evaluated only multiorgan dysfunction, but other less critical symptoms of this condition may well sap the quality of life of these individuals, adding to the burden on GPs and other primary healthcare practitioners.
The known inequities in healthcare access, healthcare provision across the country, and blocks inpatient care pathways, are obstacles that could make the management of this condition even more difficult. However, integrated care pathways are essential to handle this risk.
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.”
With increased risk observed across age groups, and relatively higher risk among ethnic minorities, more studies are urgently required to understand the risk factors and target at-risk groups for necessary management.