A firm recommendation: measuring the softness of infant sleep surfaces.

Background: Approximately 3600 sudden unexpected infant deaths (SUID) occur annually in the United States, and a quarter of SUIDs are caused by unintentional suffocation and strangulation in bed, with soft bedding use being a significant risk factor. Therefore, The American Academy of Pediatrics (AAP) recommends infants sleep on a "firm" surface, though neither an objective definition nor national standard has been established. The purpose of this study is to report on the performance of a device that measures mattress softness and to provide quantitative values of softness for various infant sleep surfaces.