Procedures
Clinical data including demographic characteristics (age, gender,
smoking status), antiviral treatment (hydroxychloroquine, favipiravir,
convalescent plasma, steroids), chest tomography results and
complication development during hospitalization were obtained from the
hospital electronic record system. Patients were classified into 2
groups: ICU patients (followed in the ICU due to COVID-19) and non-ICU
patients (hospitalized due to COVID-19 but followed in the pulmonary
ward).
Patients were invited to the follow-up visit, by healthcare
professionals, by telephone. All participants were consulted face to
face by an investigator; asked to complete a questionnaire to assess
their health status (Short Form-36, SF-36); and asked for persistent
symptoms such as dyspnea, fatigue, muscle weakness etc. A trained
physiotherapist performed a 6-min walking test to assess functional
exercise capacity. The pulmonary function test was performed in the
Pulmonary Functional Centre in University of Health Sciences, Dr. Suat
Seren Chest Disease and Thoracic Surgery Teaching and Research Hospital
according to American Thoracic Society and European Respiratory Society
spirometry standardizations20.
Chest high-resolution computed tomography (HRCT) was performed at the
end-inspiration in supine position, 1.25 mm section thickness and 0.625
mm reconstruction with high resolution. An experienced radiologist
cross-compared HRCT images during hospital stay and follow-up HRCT
images. If a participant had more than one HRCT, final chest images were
included in the comparison. Both lungs were divided into 5 lobes in
accordance with normal anatomical structure. Each lung lobe was given a
score according to the following criteria; 0, no involvement; 1, less
than 5% involvement; 2, 5-25% involvement; 3, 25-50% involvement; 4,
50-75% involvement; 5, more than 75% involvement. The total CT score
was calculated semi-quantitatively with the sum of the scores of the
five lobes21.
The SF-36 test is a 36-item self-reported survey of quality of life.
SF-36 contains eight categories that assess physical functioning, social
functioning, role limitation due to physical and emotional problems,
general and mental health, bodily pain and vitality. Each category is
scored from 0 (worst) to 100 (best) with higher scores showing better
quality of life22. The translated and validated
version of SF-36 was used for the study23.
The primary outcome was the percentage of patients with lung involvement
in the 6-month follow up CT scan.
Secondary outcomes were exercise capacity (distance of 6-min walking
test), pulmonary function tests and health state scores at the follow up
visit.