Test Characteristics
Respiratory culture testing demonstrated low sensitivity (24.3%) and
moderate specificity (85.2%) as screening tests for ARI in children
with tracheostomies (Table 4 ), indicative of poor test
concordance with clinician diagnosis. Similarly, respiratory cultures
demonstrated a poor positive predictive value (36.5%) and only a fair
negative predictive value (76.3%), indicating limited effectiveness at
identifying ARI in children with tracheostomies. Positive likelihood
ratio(+LR) was determined to be 1.64, and negative likelihood ratio(-LR)
0.89. BAL specimens had a higher specificity (90.4%) and negative
predictive value (90.1%), but still generally poor test
characteristics. TA cultures had very poor test performance as screening
tests in all measures (Table 4 ).