Pulmonary Manifestations and their Determinants in Long Covid Patients: A Retrospective Cohort Study after One Year Follow-Up, From Iran

Abstract

Background and aim Post-Covid-19 condition or long covid syndrome (LCS), including both pulmonary and extra-pulmonary manifestations, were reported in about 90% of covid-19 infected hospitalized patients. This study aims to determine pulmonary manifestations of LCS and its associated factors in hospitalized patients. Methods This retrospective cohort study was conducted on patients who were admitted due to Covid-19 in the referral hospital of Covid-19 in Shiraz, Iran. The list of patients with a history of hospital admission due to Covid-19 was provided by the deputy for curative affairs of Shiraz University of Medical Sciences (SUMS), Shiraz, Iran. Then, by systematic randomized sampling method, 300 patients were selected and invited to come to Motahari Clinic affiliated to SUMS, Shiraz, Iran. A general questionnaire including demographic and socioeconomic factors was filled out for every patient. We evaluated the patients in three stages: pre-hospital, hospital, and post-hospital. A Modified Medical Research Council (mMRC) questionnaire was also used for dyspnea assessment and pulmonary function test (PFT) was performed for examining lung function. Finding 290 patients with a mean age of 53.23±13.4, and female to male ratio of 1.65, accepted our invitation and referred to the clinic. Of the participants, 115(39.7%) were previously diagnosed with diabetes mellitus (DM), cardiovascular disease (CVD), or obesity (BMI > 30). The mean length of hospital stay due to covid-19 was 8.78±1 days (median = six days) while 47(16.2%) had a history of admission to ICU. This study was conducted about one year after the patients were discharged from the hospital (mean=327±124.4 days, median = 306 days). Out of all, 176 (60%) had mMRC score≥1, including 66 (22.8%) with severe dyspnea. Furthermore, 147 (50.7%) had abnormal PFTs, including 123 (42.4%) with impaired TLco and 46 (15.8%) with a restrictive pattern of lung disease. In univariate analysis, patients who were admitted to the ICU (p=0.002) or who had received corticosteroids (p=0.024) during hospital admission showed milder dyspnea after one-year follow-up. Logistic regression revealed a reverse association between ICU admission and the severity of dyspnea (p=0.04). Conclusion Appropriate treatment and care during hospitalization and continued regular follow-up for at least one year after discharge is crucial to provide a significant enhancement of Covid-19 infected patient's overall prognosis. The Long-term pulmonic consequences of Covid-19 need special attention.