Results
A total of 269 COVID-19 patients were discharged from our hospital between 1 April and 1 September 2020 and 70 patients were included in the study (Figure 1). The demographic and clinical characteristics of the participants are shown in table 1. Median age of participants was 56 years, and 60 (75%) of them were male. Most common comorbid diseases were hypertension (40%) and DM (33%). Thirty-one patients (44%) were admitted to the ICU and the median length of ICU stay was 9 days. Median length of hospital stay was 12 days and the time from the onset of symptoms to follow-up visit was 198 days.
ICU patients had a higher median CT score at admission than non-ICU patients [17 (11-24) vs. 11 (10-15) respectively, p=0.002]. CT scores at the follow-up visit remained higher in ICU patients. All of the patients had at least one CT finding at admission, 20 ICU patients (65%) and 12 non-ICU patients (31%) had at least one CT finding in the follow-up CT (p=0.005) (Table 2). The most common CT finding was ground glass opacity (GGO) in the follow-up CT, followed by subpleural lines and irregular lines.
79% of participants had at least one persistent symptom. Individuals who were discharged from the ICU had a higher percentage of persistent symptoms, 90% vs 67% (p=0.033). Effort dyspnea was the most common persistent symptom followed by fatigue and muscle weakness (e–Table 1). Women had a higher percentage of persistent symptoms than men (e–Table 2).
A total of 65 participants (93%) completed the pulmonary function test (PFT) and 5 participants were unable to complete the test. Results of PFT are summarized at table 3. Forced vital capacity (FVC), peak expiratory flow (PEF) and peak inspiratory flow (PIF) were the most commonly affected parameters in ICU patients. PEF and PIF were also the two most commonly affected parameters in non-ICU patients. Higher CT scores at follow-up visits were found to be associated with impairment of PFT (Table 4).
The median distance of 6-minute walk tests was similar in both groups; 445m in ICU patients, and 461 meters in non-ICU patients. When participants were stratified into age and weight, 13 participants (42%) in the ICU group, and 11 participants (28%) in the non-ICU group, were below 80% of the expected distance.
Assessment of quality of life, by SF-36, were similar in the two groups. Social functioning, role limitation due to physical and emotional problems were the most affected SF-36 categories (Table 3). The quality of life scores were lower in female participants than male participants (e–Table 3).
When the presence of ICU admission, age, gender, and CT score at admission were introduced into a logistic regression model, only patients age (OR 1.08, 95% CI 1.02-1.15) and higher CT score at admission (OR 1.13, 95% CI 1.01-1.27) were independent risk factors for having at least one radiological abnormality at a follow-up CT.