Table 5.

Comparison of length of stay between the matched pairs (Days)

Variable	Number of Pairs (n = 175)	Difference of length of stay in pairs Median (range)	Statistics (Z)	P
Classification of the number of hospital beds
1	29	4.0(−8~ 107)	3.136	0.002
2	47	4.0(−30~ 52)	2.131	0.033
3	49	6.0(−56~ 134)	2.716	0.005
4	50	6.0(−94~ 52)	2.045	0.041
Classification of GDP
1	19	5.0(−23~ 69)	2.439	0.015
2	71	3.0(−94~ 134)	1.712	0.087
3	37	4.0(−30~ 88)	2.106	0.035
4	48	7.0(−39~ 107)	3.847	0.000
HAIs sites
Upper respiratory	23	3.0(−21~ 14)	− 2.236	0.026
Blood related	5	6.0(−22~ 20)	−0.135	0.893
Superficial incision	20	10.0(−3~ 107)	−3.680	0.000
Organ lacunar	2	4.5(3~ 6)	−1.342	0.180
Deep incision	6	12.0(−10~ 52)	− 1.802	0.072
Intra-abdominal tissue	1	5.0(5~ 5)	/	/
Urinary	23	6.0(−13~ 88)	−2.480	0.013
Skin soft-tissue	12	1.0(−14~ 32)	0.157	0.875
Lower respiratory	76	5.0(−94~ 134)	−2.439	0.015
Gastrointestinal	6	1.0(−22~ 54)	−0.674	0.500
Other	1	11.0(11~ 11)	/	/