Adherence to Antipsychotic Medications for Schizophrenia Among Latinos and Asians with Limited English Proficiency

Authors: Victoria D. Ojeda, PhD, MPH¹, Concepción Barrio, PhD², Dahlia Fuentes, MPH, MSW² Nicole Lanouette, MD³ , Piedad Garcia, EdD⁴ , Todd P. Gilmer, PhD¹

Background:
This paper examined the relationship between preferred language for mental health services including English, Spanish, or an Asian language and adherence to treatment with antipsychotic medication among non-Latino white, Latino and Asian Medi-Cal beneficiaries with schizophrenia in San Diego County, California.

Methods:
Data included 31,560 person-years from 1999 to 2005. Pharmacy records were analyzed to assess adherence to antipsychotic medication, measured as the cumulative possession ratio (CPR) (the number of days medications were available for consumption divided by the number of days subjects were eligible for Medi-Cal). Clients were defined as nonadherent (CPR<0.5), partially adherent (0.5<=CPR<0.8), adherent (0.8<=CPR<=1.1), or as an excess filler (CPR>1.1). A multivariate multinomial regression model was used to examine adherence among clients defined by race/ethnicity and language groups; covariates included age, gender, living situation, substance use disorder, and conservatorship status.

Results:
Limited English Proficient (LEP) Latinos were more likely to be adherent to antipsychotic medications than English Proficient (EP) Latinos (40.8% vs. 35.9%, P<.001). LEP Latinos were less likely to be excess fillers than EP Latinos (15.1% vs. 20.4%, P<.001). LEP Asians were less likely to be adherent than EP Asians (40.7% vs. 45.1%, P=.026). Compared to EP Asians, LEP Asians were more likely to be nonadherent (28.7% vs. 22.0%, P<.001), but were less likely to be excess fillers (12.5% vs. 17.4%, P=.004). Controlling for adherence, LEP clients were less likely to be hospitalized and exhibit lower health services, pharmacy, and total costs than EP and white clients.

Conclusions:
Adherence to antipsychotic medications varies among ethnic groups and within those, by preferred language for receipt of mental health services. Researchers and clinicians should consider race/ethnicity and language when developing interventions to improve medication adherence. Policies to support the training of bilingual and multicultural ethnic minority providers may improve adherence to treatment by populations with diverse cultural and linguistic needs.