Association between preserved ratio impaired spirometry and 1-year clinical outcomes in patients with bronchiectasis patients: A cohort study

Background: Preserved Ratio Impaired Spirometry (PRISm) (defined as the ratio of forced expired volume in the first second to forced vital capacity (FEV1/FVC) greater than 0.70 with a FEV1 of less than 80% predicted) is associated with a higher risk of hospitalizations and mortality in the general population. However, less is known about whether PRISm is associated with adverse clinical outcomes in patients with bronchiectasis. We aimed to investigate whether PRISm is associated with adverse clinical outcomes in bronchiectasis patients. Methods: We performed a retrospective cohort study with inpatients admitted with acute exacerbations of bronchiectasis between January 2017 and January 2022. Clinical data including anthropometry, spirometry, laboratory, etiological and radiologic variables were collected. Patients were divided into the normal spirometry group, the PRISm group and the obstructive spirometry group. All patients were followed up for 1 year. The primary outcome was readmission of bronchiectasis at 1 year. Results: Of 487 bronchiectasis patients, we found 142 (29.2%) had normal spirometry, 67 (13.8%) had PRISm and 278 (57.1%) had obstructive spirometry. Patients with obstructive spirometry were more likely to be male and to smoke, had higher fibrinogen values and more lobes affected. Patients with PRISm (HR 1.929, 95% CI 1.049 to 3.546) and obstructive spirometry (HR 2.406, 95%CI 1.506 to 3.845) had a higher risk of readmissions compared with those with normal spirometry after adjustment for potential confounders. Conclusions: PRISm was associated with significant increased risk for readmissions in patients with bronchiectasis compared with normal spirometry, which should receive special attention.