Assessment of COVID-19 incidence after performing pulmonary function tests during the pandemic: Findings from a real-life cohort

Background: Pulmonary function testing (PFT) is paramount in assessing patients with respiratory symptoms and chronic cardiopulmonary diseases. Although seminal studies have demonstrated that PFT generates aerosols, this simple observation does not confirm the potential for enhanced pathogen transmission.

Objective: We aimed to describe the frequency of patients who developed suspected symptoms of COVID-19, prompting SARS-CoV-2 testing after undergoing PFT during the reopening of a laboratory amid the deceleration of the pandemic.

Methods: We analyzed a retrospective cohort of individuals referred for PFT between May and August 2021. Two weeks post-PFT, phone calls were made asking about suspected symptoms of COVID-19, leading to SARS-CoV-2 testing. The medical data of the participants who did not answer the phone calls were reviewed through institutional electronic records. The minimum sample size of 338 individuals was calculated to detect an incidence of COVID-19 at least ten times higher than the surrounding local rate (0.08 %).

Results: Three hundred and sixty patients (40.6 % men; 56.5 ± 17.6 years) were included. PFT was primarily indicated for functional and prognostic assessments of chronic respiratory diseases. Three hundred and sixteen patients answered the follow-up phone calls. Following PFT, most patients (357/360) did not report suspected symptoms leading to COVID-19 confirmation testing. Three patients underwent RT-PCR testing, which yielded negative results.

Conclusion: Patients in this real-life cohort, after performing PFT, did not experience an outbreak (with a rate of at least ten times the surrounding local rate) or a cluster (with two or more cases) of symptomatic COVID-19.