Temporal Trends in the Use of Pulmonary Function Tests Before, During, and After the COVID-19 Pandemic: Experience from a University Hospital in Türkiye

The coronavirus disease-2019 (COVID-19) pandemic has disrupted healthcare globally, including diagnostic services. 1n Trkiye, healthcare restrictions began shortly after March 11, 2020.Pulmonary function test (PFT) use, especially spirometry, declined because of concerns about transmission, which may indicate unmet healthcare needs. 2 The use and quality of PFTs declined during the pandemic due to concerns about infection transmission. 3recent nationwide study by Grek Dilektal et al. 4 highlighted substantial reductions in PFT practices and variability in adherence to safety protocols across Trkiye during the pandemic.We conducted a study reviewing trends in the use of PFTs before, during, and after the COVID-19 pandemic in the outpatient pulmonology clinic of a university hospital.This retrospective, cross-sectional, single-center study reviewed outpatient visits and the number of PFTs performed at the Ankara University Hospital Chest Diseases Department from May 1, 2019, to December 31, 2024.Data were grouped into pre-pandemic (pre-COV), before the World Health Organization's declaration of the global pandemic on March 11, 2020; pandemic (COV), until the official end of the emergency status on May 31, 2023; and post-pandemic (post-COV), through December 31, 2024.The PFT laboratory data included monthly totals for spirometry, lung volumes measured by the multiple-breath nitrogen washout method and by body plethysmography, and carbon monoxide diffusing capacity.Monthly counts of new COVID-19 cases were extracted from online open data sources. 5Data were summarized as mean standard deviation or median [25 th -75 th percentiles], with normality assessed by the Shapiro-Wilk test and by visual inspection.ANOVA or Kruskal-Wallis tests were used for comparisons.Statistical analyses were performed using SPSS v27; significance was set at P < 0.05.The mean monthly number of outpatient clinic admissions (P < 0.001), the median monthly number of spirometry tests (P < 0.001), the median monthly number of diffusing lung capacity measurements (P < 0.001), and the mean monthly number of lung volume measurements (P < 0.001) all varied significantly.The spirometry-to-outpatient-admission ratio differed significantly (P < 0.001), while no significant difference was observed between the pre-COV and post-COV periods (P = 0.19) (Table 1).A comparison of the spirometry-to-admission ratio across the periods is illustrated in Figure 1.Trends in cases and healthcare statistics over time are shown in Figure 2.