Examining the impact of migrant status on ethnic differences in mental health service use preceding a first diagnosis of schizophrenia

Some ethnic groups have more negative contacts with health services for first-episode psychosis, likely arising from a complex interaction between ethnicity, socio-economic factors, and immigration status. Using population-based health administrative data, we sought to examine the effects of ethnic group and migrant status on patterns of health service use preceding a first diagnosis of schizophrenia or schizoaffective disorder among people aged 14-35 over a 10-year period. We compared access to care and intensity of service use for first-generation ethnic minority groups to the general population of Ontario. To control for migrant status, we restricted the sample to first-generation migrants and compared service use indicators for ethnic minority groups to the European migrant group. Our cohort included 18,080 people with a first diagnosis of schizophrenia or schizoaffective disorder, of whom 14.4% (n = 2607) were the first-generation migrants. Our findings suggest that the magnitude of ethnic differences in health service use is reduced and no longer statistically significant when the sample is restricted to first-generation migrants. Of exception, nearly, all migrant groups have lower intensity of primary care use, and Caribbean migrants are consistently less likely to use psychiatric services. We observed fewer ethnic differences in health service use preceding the first diagnosis of psychosis when patterns are compared among first-generation migrants, rather than to the general population, suggesting that the choice of reference group influences ethnic patterning of health service use. We need a comprehensive understanding of the mechanisms behind observed differences for minority groups to adequately address disparities in access to care.