BACKGROUND: Substance use during pregnancy has negative consequences for infants, including preterm birth, low birth weight, and neonatal abstinence syndrome (NAS). In Wisconsin, there are racial and ethnic disparities in maternal substance use and NAS. Notably, the maternal substance use rate at delivery hospitalization among Native American women is two times the rate among White women, and the NAS rate among Native American infants is three times the rate among White infants. Identifying women at risk of substance-exposed pregnancies, including those affected by mental health and substance use (MHSU) disorders, is critical in optimizing outcomes for mothers and infants. We examined the prevalence of (MHSU) disorders among Native American women of reproductive age (WRA).
METHODS: We applied a novel algorithm to identify inpatient hospitalizations primarily for mental and substance use (MHSU) among American Indian women of reproductive age (15-44 years) from 2011-2015. The algorithm classifies hospitalizations as MHSU based on diagnosis-related group codes, ICD-9-CM diagnosis codes, and procedure codes.
RESULTS: A total of 6,994 hospitalizations among Native American WRA were identified, with 1,463 primarily for MHSU. Following delivery hospitalization, MHSU was the second leading cause of hospitalization (rate=243.5/10,000) for Native American WRA. The majority (65.6%) of MHSU hospitalizations were primarily for mental health rather than substance use (n=960), with 52% (n=767) of all MHSU hospitalizations identified with a co-occurring MHSU condition. For substance-related hospitalizations alone, 49% had a co-occurring MHSU condition. Compared to White WRA, the rate of MHSU was nearly two times higher among Native American WRA (RR=1.8).
CONCLUSIONS: We observed high rates of MHSU hospitalization among Native American WRA in Wisconsin, suggesting that this population may be vulnerable to adverse mental health and substance use outcomes, including substance dependence and negative pregnancy outcomes. These data can inform public health prevention efforts focusing on comprehensive care for WRA, including integration of family planning, mental health, and substance-related services.