Table 3. Zero-Inflated Poisson Regression Predicting Hospitalization for Pulmonary Exacerbation Over Year of Study.

Number of hospitalizations	IRR	Robust standard error	z	P value	95% confidence interval
PPI use	1.75	0.453	2.17	0.03	1.06	2.91
ppFEV1	0.98	0.007	-2.84	0.005	0.97	0.99
BMI	1.01	0.024	0.32	0.751	0.96	1.06
Homozygous ΔF508	1.38	0.340	1.3	0.195	0.85	2.23
Chronic pseudomonas colonization	0.63	0.203	-1.44	0.149	0.33	1.18