Post COVID-19 hospitalizations in patients with chronic inflammatory diseases - A nationwide cohort study

Abstract

Objective: To study long term consequences of hospitalization for COVID-19 in patients with chronic inflammatory diseases. We studied the risk of subsequent hospitalizations in patients with chronic inflammatory diseases, who survived a hospitalization for COVID-19, compared to other patients who had been hospitalized for COVID-19.

Design and setting: Population based cohort study based on Danish nationwide health registers. The study population included all adult patients in Denmark who had been discharged alive after a hospitalization with COVID-19 from March 1, 2020 to July 31, 2021.

Population: From the study population, the exposed cohort constituted patients who had inflammatory bowel diseases (IBD), rheumatoid arthritis (RA), spondyloarthropathy (SpA), or psoriatic arthritis (PsA) prior to hospitalization for COVID-19, and the unexposed cohort constituted those without these diseases.

Main outcome measures: We estimated the adjusted Hazard Rate (aHR) for the following outcomes: overall risk of hospitalization, cardiovascular diseases, respiratory diseases, blood and blood-forming organs, nervous system diseases, infections, sequelae of COVID-19, and death.

Results: A total of 417 patients with IBD/RA/SpA/PsA were discharged alive after COVID-19, and 9,248 patients without these diseases. Across the different outcomes examined, the median length of follow up was 6.50 months in the exposed cohort (25-75% percentiles: 4.38-8.12), and among the unexposed the median time of follow up was 6.59 months (25-75% percentiles: 4.17-8.49). Across different analyses, we consistently found a significantly increased risk of hospitalizations due to respiratory diseases (aHR 1.27 (95% CI 1.02-1.58)) and infections (aHR 1.55 (95% CI 1.26-1.92)). In sensitivity analyses, the overall risk of hospitalization was aHR 1.15 (95% CI 0.96-1.38) and the risk of hospitalization due to cardiovascular diagnoses was aHR 1.14 (95% CI 0.91-1.42). During the time of follow up, the risk of nervous system diagnoses or death was not increased in patients with IBD/RA/SpA/PsA.

Conclusions: After hospitalization with COVID-19, patients with IBD/RA/SpA/PsA had an increased risk of subsequent hospitalizations for a number of categories of diseases, compared to other patients who have been hospitalized with COVID-19. These results are disturbing and need to be examined further. The implication of our results is that clinicians should be particularly alert for post COVID-19 symptoms from several organ systems in patients with IBD/RA/SpA/PsA.

Keywords: COVID-19; Chronic inflammatory diseases; Clinical epidemiology; Long-term COVID-19; Post-acute COVID-19.