. 2010 Jul 7;10:196. doi: 10.1186/1472-6963-10-196

Table 4.

Factors associated with total length of stay for potentially preventable hospitalisations during the first two years of life for all children in the sample: results from the negative binomial regression models

Disease category	All five Diseases			Gastroenteritis and dehydration			Asthma and chronic bronchitis			Acute upper respiratory infections			Lower respiratory infections			Acute injuries and poisonings
Explanatory variable
	IRR		95%CI	IRR		95%CI	IRR		95%CI	IRR		95%CI	IRR		95%CI	IRR		95%CI

Economic status (reference: high income)
Poverty	2.89	**	2.50-3.34	2.24	**	1.74-2.88	1.83		0.70-4.77	1.70	**	1.31-2.19	2.67	**	2.30-3.10	6.05	**	1.54-23.74
Near poverty	1.26	**	1.19-1.32	1.27	**	1.17-1.37	2.22	**	1.50-3.30	1.16	**	1.08-1.25	1.31	**	1.23-1.39	1.24		0.82-1.89
Middle income	1.17	**	1.12-1.22	1.24	**	1.16-1.33	1.67	*	1.12-2.48	1.22	**	1.14-1.30	1.22	**	1.16-1.29	1.04		0.70-1.53
Geographic environment (reference: big city)
Small city/town	1.14	**	1.09-1.19	1.12	**	1.05-1.20	1.03		0.67-1.58	1.21	**	1.13-1.29	1.12	**	1.06-1.17	1.20		0.87-1.67
Rural area	1.20	**	1.16-1.26	1.18	**	1.11-1.26	1.03		0.68-1.55	1.36	**	1.28-1.45	1.19	**	1.13-1.26	1.35		0.99-1.84
Physical conditions at birth
Male	1.20	**	1.16-1.25	1.07	*	1.01-1.12	1.90	**	1.40-2.58	1.18	**	1.12-1.24	1.21	**	1.16-1.26	1.14		0.90-1.44
Low birth weight	2.82	**	2.53-3.13	1.52	**	1.30-1.78	2.88	**	1.36-6.07	1.28	**	1.09-1.52	2.92	**	2.59-3.28	0.53	*	0.29-0.99
Number of outpatient visits in the first week of life	1.17	**	1.11-1.24	1.25	**	1.15-1.36	1.42		0.98.-2.06	1.25	**	1.15-1.36	1.13	**	1.05-1.22	0.78		0.57-1.07
Additional physical conditions related to potentially preventable hospitalisations before age two
Number of outpatient visits for the same disease before age two	1.03	**	1.03-1.03	1.29	**	1.28-1.30	2.44	**	2.19-2.71	1.02	**	1.02-1.02	1.14	**	1.14-1.15	2.33	**	2.19-2.47
Access to preventive care
Number of well-child care visits before age two	0.93	**	0.91-0.94	0.98	**	0.96-0.99	0.93		0.86-1.00	1.01		1.00-1.03	0.93	**	0.91-0.95	0.83	**	0.76-0.90

Number of observations	218,158			218,158			218,158			218,158			218,158			218,158
Model significance: Wald Χ²(10)	7,663.18		**	3,501.02		**	301.98		**	1,112.16		**	10,311.12		**	900.49		**

IRR: incidence-rate ratio.

CI: confidence interval.

* p < 0.05; ** p < 0.01.