Sudden Unexpected Infant Death Rates and Social Determinants of Health Among Hispanic Infants.

IMPORTANCE

Sudden unexpected infant death (SUID) is the leading cause of postneonatal mortality, with disparities attributed to social determinants of health (SDOH). SUID in the Hispanic population has received limited attention, despite the fact that one-fourth of US children are Hispanic.

OBJECTIVE

To compare SUID rates and risk factors among Hispanic and non-Hispanic infants, and associated interactions among SUID, SDOH, and acculturation.

DESIGN, SETTING, AND PARTICIPANTS: This US nationwide retrospective cohort study used US National Center for Health Statistics (NCHS) linked birth and infant death data, and Pregnancy Risk Assessment Monitoring System (PRAMS) data from 1996 to 2017. All live births (NCHS) or participants (PRAMS) with documented maternal ethnicity were included. Data were analyzed from February to October 2024.

EXPOSURE

Maternal Hispanic ethnicity.

MAIN OUTCOMES AND MEASURES

The primary outcome was postneonatal SUID occurring at age 28 to 364 days, as designated by International Classification of Diseases, Ninth Revision codes 798, 799, and 913 (1996-1999), and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes R95, R99, and W75 (2000-2017). Odds ratios (ORs) were calculated by exposure, and adjusted ORs controlled for risk factors in a multivariable model. Maternal nativity variables associated with race, poverty, local SUID rates, and region of origin were investigated. Subgroup analysis explored the relative association of Hispanic ethnicity with SUID risk factors. Maternally reported risk factors were compared according to Hispanic ethnicity.

RESULTS

Among 88 067 608 live births (median [IQR] maternal age, 27 [22-32] years; median [IQR] gestational age, 39 [38-40] weeks) and 54 828 SUID deaths, there were 7173 SUID deaths among 19 887 156 Hispanic infants. The SUID rate was lower for Hispanic infants (0.36 deaths per 1000 live births) than for non-Hispanic infants (0.70 deaths per 1000 live births), across essentially all factors analyzed. Overall, Hispanic infants had 33% lower odds of SUID than non-Hispanic infants (adjusted OR, 0.67; 95% CI, 0.65-0.69). Infants of non-US-born Hispanic mothers had lower SUID rates, regardless of race, county-level poverty, local SUID rates, or Hispanic region of origin, except Puerto Rican infants. Altered associations with detrimental and protective factors were found, despite a mixed picture of risk.

CONCLUSIONS AND RELEVANCE

In this cohort study of SUID in infants born from 1996 to 2017, Hispanic infants had lower SUID rates than non-Hispanic infants, despite adverse SDOH. Risk factors operated differently in Hispanic infants, challenging current conceptualizations of risk. Understanding how risk operates in Hispanic populations can help to better address the mortality burden of SUID.