Table 4 Association between oral polio vaccine (OPV) immunisation coverage and mortality rates of sudden infant death syndrome (SIDS) (United States, 1975–2009)
| Estimate [per 10% increase] | IRR (95% CI) | |
|---|---|---|
| OPV immunisation coverage | −0.07 | 0.94 (0.89, 0.98) |
| Infant sleep position (supine) | −0.12 | 0.89 (0.86, 0.92) |