Table 2.

Discrimination of comorbidity scoring systems for severe maternal morbidity in California birth data, 2011–2017 (N = 3,308,554)

	N (column %)	Mean SMM comorbidity score (SD)	Area under ROC curve	Area under PR curve
All	3,308,554 (100)	2.6 (5.0)	0.69	0.10
Race-Ethnicity (n = 3,225,224)
American Indian-Alaska Native	10,920 (<1)	3.6 (5.8)	0.71	0.12
Asian	386,864 (12)	2.1 (4.4)	0.68	0.09
Black	164,943 (5)	4.0 (6.3)	0.71	0.12
Latinx	1,545,628 (48)	2.5 (4.8)	0.68	0.10
Pacific Islander	97,288 (3)	3.4 (5.8)	0.68	0.11
White	888,017 (28)	2.7 (5.0)	0.69	0.08
Multi-race	127,540 (4)	3.3 (5.5)	0.70	0.09
Other	4,024 (<1)	2.6 (5.0)	0.68	0.12
Nativity (n = 3,308,355)
Born in U.S.	2,074,588 (63)	2.9 (5.2)	0.69	0.09
Not born in U.S.	1,233,767 (37)	2.4 (4.7)	0.69	0.11
Payment method (n = 3,304,448)
Commercial insurance	1,588,867 (48)	2.8 (5.1)	0.69	0.09
Government programs	1,560,790 (47)	2.6 (5.0)	0.69	0.11
Other	154,791 (5)	2.1 (4.3)	0.70	0.10
Educational Attainment (n = 3,165,563)
Less than high school graduate	567,248 (18)	2.6 (4.9)	0.69	0.10
High school graduate or equivalent	808,836 (26)	2.6 (5.0)	0.69	0.10
Some college	845,156 (27)	2.8 (5.2)	0.69	0.09
College graduate or higher	944,323 (30)	2.5 (4.9)	0.69	0.08

SMM, severe maternal morbidity; IQR, interquartile range; ROC, receiver operating characteristic