Factors Affecting the Risk of Interstitial Lung Disease Development in Hospitalized PatientsWith COVID-19 Pneumonia

BACKGROUND: Coronavirus disease 2019 (COVID-19) related chronic lung changes secondary to severe disease have become well known. The aim of this study was to determine the risk factors that affect the development of interstitial lung disease in subjects with COVID-19 pneumonia who were hospitalized. METHODS: Patients hospitalized with COVID-19 pneumonia between June 2020 and March 2021 were retrospectively analyzed. Smoking histories, comorbidities, reverse transcriptase polymerase chain reaction test results, laboratory parameters at the time of the diagnosis, oxygen support, the use of corticosteroids with dosage and duration data, the need for ICU care were recorded. High-resolution computed tomographies (HRCT) were obtained for study population in their 3-6 months follow-up visit. The subjects were classified as having residual parenchymal lung disease if a follow-up HRCT revealed parenchymal abnormalities except pure ground-glass opacities (the residual disease group). The control group consisted of the subjects with normal chest radiograph or HRCT in their follow-up visit or the presence of pure ground-glass opacities. Two groups were compared for their demographic and clinical abnormalities, laboratory parameters, treatment regimens, and the need for ICU care. RESULTS: The study included 446 subjects. The mean +/- SD age was 58.4 +/- 13.87 years, with 257 men (57.6%). Although 55 subjects had normal HRCT features on their follow-up HRCT, 157 had abnormal lung parenchymal findings. Univariate logistic regression analysis revealed statistically significant results for age, sex, corticosteroid treatment, and the need for ICU care for predicting interstitial lung disease development (P <.001, P = .003, P <.001, and P <.001, respectively). Also, the residual disease group had significantly higher leukocyte and neutrophil counts and lower lymphocyte counts (P <.001, P <.001, P = .004, respectively). Correlated with these findings, neutrophil-to-lymphocyte ratios and platelet-to-lymphocyte ratios were significantly higher in the residual disease group (P <.001 and P = .008, respectively). CONCLUSIONS: Residual parenchymal disease was observed 3-6 months after discharge in one third of the subjects hospitalized with COVID-19 pneumonia. It was observed that interstitial lung disease developed more frequently in older men and in those subjects with more-severe disease parameters.