Risk adjustment models for interhospital comparison of CS rates using Robson’s ten group classification system and other socio-demographic and clinical variables

Table 3 Crude and adjusted c-section RRs of hospitals in group II

Hospital	n	Crude RR	p–value	Adj* RR	p–value	% variation†
A	269	1.61	<0.001	1.52	<0.001	−5.6
B	145	1.54	<0.001	1.51	<0.001	−1.9
C	99	1.04	0.756	0.99	0.952	−4.8
D	37	2.13	<0.001	2.15	<0.001	0.9
E	260	1.11	0.257	1.13	0.159	1.8
F	347	1.24	0.006	1.25	0.004	0.8
G	324	1.18	0.040	1.22	0.012	3.4
H	81	1.78	<0.001	1.63	<0.001	−8.4
I	202	1.36	<0.001	1.35	<0.001	−0.7
J	315	1.09	0.330	1.09	0.297	0.0
K	226	1.53	<0.001	1.46	<0.001	−4.6
L	504	0.99	0.871	0.98	0.787	−1.0
M	54	0.65	0.087	0.64	0.070	−1.5
N	118	0.78	0.112	0.79	0.130	1.3
O	143	0.86	0.244	0.85	0.228	−1.2
P	369	1.41	<0.001	1.39	<0.001	−1.4
Q	644	1.22	0.003	1.20	0.007	−1.6
R	630	1.34	<0.001	1.33	<0.001	−0.7
S	113	2.26	<0.001	2.14	<0.001	−5.3
T	36	2.11	<0.001	2.05	<0.001	−2.8
U	405	1.62	<0.001	1.54	<0.001	−4.9
V	674	1.08	0.267	1.05	0.482	−2.8
W	779	1.22	0.002	1.21	0.002	−0.8
X	649	0.72	<0.001	0.75	<0.001	4.2
Y	266	1.51	<0.001	1.47	<0.001	−2.6

* Adjusted for: age, severe co-morbid illness of the mother, diabetes, ante-partum haemorrhage/abruption placentae/placenta praevia, eclampsia/pre-eclampsia, foetal-pelvic disproportion/excessive development of the infant, premature rupture of the membranes, post-maturity and macrosomia.
† The % variation is computed as (crude RR-adj RR)*100/crude RR.

ISSN: 1471-2393