Impact of colonizing organism in the respiratory tract on the incidence, duration, and time between subsequent hospitalizations among patients with cystic fibrosis

Abstract

Background: This study aimed to examine the association between colonizing respiratory tract organism and frequency, duration, and time between subsequent hospitalizations among hospitalized patients with cystic fibrosis (CF).

Methods: This retrospective cohort study of 312 CF patients from 2 New York City hospitals (2006-2016) examined the effects of colonization with Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus aureus (MSSA) or methicillin-resistant S aureus (MRSA), co-colonization on incidence of hospitalization, time to next hospitalization, and total length of stay (LOS).

Results: Annual rate of subsequent hospitalizations was highest in patients with P aeruginosa: adjusted incidence rate ratios (aIRRs) were 2.75 (95% confidence interval [CI], 1.72-4.41) for P aeruginosa versus MSSA, 2.57 (95% CI, 1.52-4.31) for co-colonization versus MSSA, and 1.77 (95% CI, 1.04-3.01) for P aeruginosa versus MRSA. Time to readmission was shortest for P aeruginosa: aIRRs were 1.75 (95% CI, 1.05-2.94) for MRSA versus P aeruginosa, 1.64 (95% CI, 1.03-2.59) for MSSA versus P aeruginosa, and 1.61 (95% CI, 1.04-2.47) for co-colonization versus P aeruginosa. LOS was longest for P aeruginosa: aIRRs were 3.41 (95% CI, 2.19-5.32) for P aeruginosa versus MSSA, 1.66 (95% CI, 1.01-2.75) for co-colonization versus MSSA, 2.50 (95% CI, 1.58-3.93) for P aeruginosa versus MRSA, and 2.05 (95% CI, 1.32-3.18) for P aeruginosa versus co-colonization.

Conclusions: CF patients with P aeruginosa alone experienced more hospitalizations, longer LOS, and shorter time to readmission versus patients with S aureus or both organisms.

Keywords: Hospital readmission; Methicillin-resistant Staphylococcus aureus; Methicillin-susceptible Staphylococcus aureus; Pseudomonas aeruginosa.