Table 4.

 Predictors of infant mortality by primary care trust in England—multivariable model

Effect	Relative risk (95% CI)*	P value
Intercept	10.915 (7.625 to 15.625)	<0.0001
Deprivation index	1.009 (1.006 to 1.013)	<0.0001
Birth rate by Pakistani ethnic group†	1.056 (1.038 to 1.074)	<0.0001
Birth rate by maternal age <18 years†	1.192 (1.115 to 1.274)	<0.0001

*Relative risk of a unit change in the X value (that is, antilog of parameter estimate).

†Log transformed rate.

Extra-Poisson variance explained in final model = 70.0%.