SIDS, or sudden infant deaths, or sudden and unexpected deaths, would be investigated by the coroners and medical examiners. The definition of SIDS is essentially that after all the investigations—they've done an autopsy and looked at everything—they cannot conclude what the infant died of. Because it was a diagnostic of exclusion, it became a nomenclature. Giving it a title, a cause of death, as “SIDS” means it's unknown.
Those cases are still in the statistics. We can get them under the “unknown” category; they're just no longer headed as “SIDS”.