. Author manuscript; available in PMC: 2010 Feb 17.

Published in final edited form as: Pediatr Pulmonol. 2009 Mar;44(3):290. doi: 10.1002/ppul.20998

TABLE 2.

Comparison of Event Rates for Sickle Cell Disease (SCD) Hospitalizations, Length of Stay, and Hematologic Variables for Children SCD With Abnormal, Pulmonary Function Abnormalities When Compared to Children With Normal Pulmonary Function, Detected From a Cross-Sectional Assessment

	In all subjects
	Normal (n = 77) (95% CI)	Restrictive (n = 13) (95% CI)	Obstructive (n = 13) (95% CI)
Rate of pain or ACS (events per patient-year)	1.23 (0.0–3.3)	1.32 (0.69–2.56), P = 0.82	2.5 (1.5–3.9), P = 0.025
Pain rate (events per patient-year)	1.02	1.08, P = 0.88	2.20, P = 0.027
ACS rate (events per patient-year)	0.21	0.23, P = 0.78	0.28, P = 0.40
Length of stay (hospital days per patient-year)	6.2 (1.3–11.1)	7.5 (3.5–16.2), P = 0.92	17.9 (10.5–30.7), P = 0.007
White blood cell count (k/mm³)	11.8	13.0	11.1
Hemoglobin (g/dl)	8.4	8.6	8.7
Fetal hemoglobin (%)	5.9	5.6	4.4

Using the poisson model with deviance scale adjustment and negative binomial (NB) method for the incidence estimation and comparison test, using normal group as the reference group.