Timing of Spirometry May Impact Hospital Length of Stay for Cystic Fibrosis Pulmonary Exacerbation.

PURPOSE: The optimal timing of spirometry during hospitalization for acute pulmonary exacerbation (PEx) in patients with cystic fibrosis (CF) is unclear. We retrospectively evaluated whether measuring spirometry earlier during hospitalization was associated with a shorter length of stay (LOS).

METHODS: In this retrospective study, we analyzed data from the electronic medical record of CF patients 6 years of age and older admitted to a single center for acute PEx requiring IV antibiotic therapy between 2009 and 2016. After excluding patient encounters with missing data on covariates, random-effects linear regression was used to predict LOS as a function of days to first pulmonary function testing (PFT), which was spirometry for our study.

RESULTS: One thousand thirty-five hospitalizations of 242 patients met inclusion criteria, with 801 including complete data on covariates. Mean LOS was 10 ± 7 days, with mean time to first PFT of 4 ± 3 days after admission. In multivariable analysis, each additional day to first PFT was associated with 0.97 days longer LOS (95% CI 0.29, 1.64; p = 0.005).

CONCLUSIONS: As CF researchers and clinicians work to improve management of PEx, the timing of spirometry during hospitalization remains an important question. Obtaining objective lung function data earlier during the course of therapy may provide information which can lead to reduced hospital LOS for PEx.