Evaluation of immunisation coverage for Aboriginal and Torres Strait Islander children using the Australian Childhood Immunisation Register

Abstract

Abstract Objective: To estimate immunisation coverage for routinely administered vaccines among children using receipt of a particular Hib vaccine (PRP‐OMP) as a proxy for Indigenous status. Methods: Until May 2000, PRP‐OMP was provided only for Indigenous children in all jurisdictions except the Northern Territory. In three one‐year ACIR‐derived birth cohorts, any child recorded on the ACIR as receiving one or more doses of PRP‐OMP as the only Hib vaccine was presumed to be Aboriginal and Torres Strait Islander. Using this proxy, estimated numbers of Indigenous children were compared with Australian Bureau of Statistics estimates, and immunisation status for recommended vaccines was estimated at 12 and 24 months by jurisdiction and remoteness compared with children who received other Hib vaccines (presumed non‐Indigenous). Results: The numbers of Aboriginal and Torres Strait Islander children estimated using this ‘proxy method’ are approximately 42% of those estimated by the ABS. Immunisation coverage (among proxy Indigenous children) at 12 months (72–76%) and 24 months (64–73%) was considerably lower than others (90–94% and 81–88%, respectively). These children had significantly lower coverage when living in accessible areas than remote areas. Conclusions and Implications: These data provide the first national measure of immunisation status and are likely to be a valid measure among those identified. Aboriginal and Torres Strait Islander immunisation coverage is 17% lower with the biggest gaps in urban areas, indicating the need for better quality data informing appropriate interventions.