Table 3.

Model validation statistics in validation sample for multivariable logistic regression models and ordinal risk index models, National Birth Defects Prevention Study, 1997–2007

Model	P-value from Hosmer-Lemeshow goodness of fit	Area under the curve (95% CI)
Multivariable models:
Spina bifida	0.88	0.55 (0.50–0.60)
Anencephaly	0.91	0.59 (0.54–0.66)
Anencephaly + spina bifida	0.94	0.56 (0.53–0.60)
Ordinal risk index model:
Spina bifida	0.71	0.55 (0.50–0.59)
Anencephaly	0.90	0.57 (0.52–0.63)
Anencephaly + spina bifida	0.72	0.56 (0.52–0.59)