Do "conditions contributing to the death" clarify the predictors of infant mortality in Texas?

Predictors of infant mortality are usually based on the underlying causes reported on infant death certificates. Death certificates also contain space for "Other significant conditions contributing to the death but not resulting in the underlying cause." We investigated whether these "contributing conditions" might clarify the predictors of infant death in Texas or interventions that might reduce deaths from the underlying causes. A "multiple cause of death" file converted the underlying causes and contributing conditions associated with each infant death in 1996 into International Classification of Diseases codes. We ranked the major underlying causes, the conditions contributing to those causes, the conditions contributing to all infant deaths, and the effect of combining the underlying causes with contributing conditions to determine the main predictors of infant mortality. We found that extreme immaturity was the most common condition, causing or contributing to 604 of the 2081 deaths in 1996. We conclude that the underlying causes provide a misleading perception of the major predictors of infant death in Texas; combining them with the conditions contributing to those deaths provides a clearer picture. Given the powerful predictive value of preterm birth for infant mortality, the limited current ability to prevent preterm birth, and the cost of its complications, expanded efforts to improve understanding of its causal processes and develop preventive strategies should be top national and state priorities.