Racial/Ethnic Disparities in Acute Psychiatric Service Use Among People Diagnosed with Mental Illness in Large California Counties

Background: Current theoretical conceptualizations of mental health systems focus on outpatient services, reserving acute psychiatric services (e.g. emergency and inpatient care) for rare, emergent situations. Additionally, individuals receiving acute care should be referred, and seen, for follow-up care in outpatient settings. However, little research has evaluated if mental health systems function as hypothesized. Furthermore, evidence consistently documents racial/ethnic disparities in mental health service use, showing that African Americans are over-represented in acute services and underrepresented in outpatient services relative to whites, while Latinos and Asians may underuse all types of services. This study examined relationships between race/ethnicity, other individual characteristics, and use of acute and outpatient psychiatric services among Medicaid beneficiaries diagnosed with mental illness in 12 large, diverse California counties to better understand the functioning of the mental health system across racial and ethnic groups.

Methods:Medicaid claims data from 2005-2011 were used to construct a longitudinal dataset for quarterly mental health service use. The sample included California Medicaid beneficiaries with a mental health diagnosis (anxiety, bipolar, depression and schizophrenia) and at least one mental health claim during the study period. Models of four dependent variables were estimated (1) counts of outpatient care, (2) any outpatient care in the quarter prior to acute care, (3) any acute psychiatric service, and (4) any outpatient care in the quarter subsequent to an acute care episode. Generalized estimating equation models were used to account for the within-person correlation with binomial or negative binomial distributions. Independent variables included race/ethnicity, gender, age, comorbid psychiatric diagnoses, county, and year.

Results: 401,775 Medicaid beneficiaries met inclusion criteria with 223,998 quarters that included an acute care event. African Americans (IRR = 0.82, p< 0.001) and Hispanics (IRR = 0.77, p< 0.001) had lower rates of outpatient visits compared to whites, while Asian Americans had slightly higher rates (IRR = 1.05, p< 0.001). This relationship of lower outpatient use held for the quarter prior to an acute event (African American (OR = 0.82, p< 0.001), Hispanic (OR = 0.82, p< 0.001)) and for the quarter after an acute care event (African American (OR = 0.82, p< 0.001), Hispanic (OR = 0.82, p< 0.001)). However, compared to whites, African Americans (OR = 1.03, p= 0.007), and Hispanics (OR = 1.11, p< 0.001) had higher odds of having an acute care event given outpatient contact, while Asian Americans had lower odds (OR = 0.70, p<0.001) of an acute care event.

Conclusion:Among Medicaid beneficiaries diagnosed with mental illness in large California counties, recent data suggest that, as in older data, African Americans and Hispanics are over represented in acute psychiatric services and underrepresented in outpatient settings. These findings are particularly troubling because African Americans and Hispanics were less likely to be seen in outpatient settings before and following acute care episodes, suggesting that mental health systems are not engaging all clients in needed follow-up care.