Immunization coverage among young children of urban immigrant mothers: findings from a universal health care system

To investigate access to effective primary health care services in children of new immigrants to Canada by assessing immunization coverage at age 2.

We used multiple linked administrative data sets to analyze primary health service use and immunizations of children born between July 1, 1997, and June 30, 1998, in Ontario, Canada. These children were linked via their mothers' records to a federal Landed Immigrant Database. We used logistic regression to assess the effect on up-to-date (UTD) status at age 2 of having an immigrant mother, controlling for patient and physician characteristics. We examined the relationship of region of origin, period of immigration, and refugee status on coverage.

The study population comprised 98 123 children, of whom 66.5% had complete immunization coverage. Children of immigrant mothers were more likely to be UTD (adjusted odds ratio, 1.15; 95% confidence interval, 1.10, 1.19) than children born to nonimmigrant mothers. Within the group of children of immigrant mothers, those whose mothers were refugees had the lowest rates of coverage (66.6%), but when adjusting for maternal age, sex, neighborhood income quintile, and health services characteristics, region of origin was the most important predictor of coverage. Those from the region of Southeast and Northeast Asia were most likely to be UTD (odds ratio, 1.63; 95% confidence interval, 1.46, 1.81). Period of immigration was not associated with coverage.

Contrary to expectations, immigrant mothers are accessing immunizations at least as well as nonimmigrants for their young children in Ontario. There is variation by region of origin and socioeconomic status. Universal access to care reduces disparities in immunization coverage, but overall rates are too low.