Table 3.

Exacerbation and Hospitalization Rates in Pseudomonas aeruginosa Culture-Positive and Culture-Negative Groups During the Pre- and Postisolation Segments, Buffalo, New York, April 1994–June 2014

Outcome	Groupa	Preisolation Segmentb (95% CI)	Postisolation Segmentb (95% CI)	P Value (pre vs post)
Exacerbation Rate	PA culture-positive	15.4 (12.6–18.6)	15.7 (13.7–17.9)	.88
	PA culture-negative	9 (7.1–11.2)	7.5 (6.3–8.9)	.20
P value (positive vs negative groups)		<.001	<.001
Overall Hospitalization Rate	PA culture-positive	4.74 (3.26–6.65)	6.25 (5.01–7.71)	.17
	PA culture-negative	4.33 (3.08–5.92)	2.44 (1.78–3.29)	.01
P value (positive vs negative groups)		.71	<.001
COPD-Related Hospitalization Rate	PA culture-positive	2.44 (1.42–3.91)	1.87 (1.22–2.74)	0.39
	PA culture-negative	1.44 (0.77–2.47)	0.89 (0.51–1.44)	0.20
P value (positive vs negative groups)		.15	.02

Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; PA, P aeruginosa.

^aIncludes only patients with nonmissing data over the 36-month period: PA culture-positive (n = 58); PA culture-negative (n = 75).

^bRates are expressed as per 100 person-months.