Using data linkage to improve the completeness of Aboriginal and Torres Strait Islander status in communicable disease notifications in Victoria.

Objective: The burden of notifiable diseases in Aboriginal and Torres Strait Islander Victorians cannot be accurately estimated due to under-reporting of Indigenous status. We used data linkage to improve completeness of Indigenous status in people notified with viral hepatitis and gonococcal infection.

Methods: Notifications made between 2009 and 2010 were linked with Victorian hospitalisation data (1997-2011). Notification rates by Indigenous status and rate ratios were calculated before and after linkage.

Results: There were 12,448 cases of hepatitis B, hepatitis C and gonococcal infection notified in Victoria in 2009-2010, with Indigenous status missing in 61.6%, 67.8%, 33.1% of these conditions, respectively. Of the total notified cases, 82% were able to be linked. Following linkage, the proportion of notifications with missing Indigenous status decreased to less than 0.2% for all conditions. Age-standardised notification rates among both Aboriginal people and non-Aboriginal people increased for all conditions.

Conclusions: Data linkage improved completeness of Indigenous status in notifications for viral hepatitis and gonococcal infection in Victoria. Completeness of these data is integral to monitoring progress in closing the Indigenous life expectancy gap.

Implications: Greater emphasis is needed on addressing prevention, treatment and care for viral hepatitis and sexually transmissible infections for Indigenous Victorians.