Table 3. Sensitivity analysis: successive linear regression analyses of nations with top infant mortality rates and the resultant r-values (2009 data).

^aAs nations with increasingly worse IMRs are added to the linear regression model, the correlation coefficients incrementally decrease (and p-values increase), likely due to worsening socioeconomic conditions and confounding.

^bNot statistically significant.

Number of nations in regression (n = 30-47)	Cutoff nation	2009 IMRs	Doses	r-valuea	p-value
30	United States	6.22	26	0.70	< .00002
31	Croatia	6.37	19	0.66	.00006
32	Belarus	6.43	16	0.57	.0006
33	Lithuania	6.47	19	0.55	.001
34	Serbia	6.75	19	0.52	.002
35	Poland	6.80	19	0.50	.002
36	Slovakia	6.84	19	0.48	.003
37	Estonia	7.32	19	0.46	.004
38	Chile	7.71	22	0.48	.002
39	Hungary	7.86	16	0.41	.009
40	Costa Rica	8.77	22	0.43	.005
41	Latvia	8.77	19	0.41	.008
42	Kuwait	8.97	19	0.39	.011
43	Ukraine	8.98	19	0.37	.014
44	Bosnia and Herzegovina	9.10	19	0.36	.016
45	Cyprus	9.70	21	0.37	.012
46	Russia	10.56	16	0.30	.040
47	Uruguay	11.32	19	0.29	.0504b