Validation and enhancement of Australian Aboriginal and Torres Strait Islander psychiatric hospitalisation statistics through an Indigenous Mental Health Worker Register.

Introduction: Inaccuracy in identification of Indigenous status on health records hampers collection of the good quality data required to guide policies, programs and services. This study examined the use of an Indigenous Mental Health Worker Register to assess the level of correct identification of Indigenous status and sources of error among psychiatric admissions within a regional public hospital information system.

Method: The study was conducted in 2004/2005 and 2005/2006 at the Cairns Base Hospital Mental Health Unit, Queensland, Australia, serving a population of 230,000 of which 13.2% identify as Aboriginal and/or Torres Strait Islander. Psychiatric admissions data, including Indigenous status, accessed from the hospital-based corporate information system (HBCIS) were compared with data collected through an Indigenous Mental Health Worker Register that is maintained through extensive networking. Investigation of mismatches enabled estimation of the frequency and sources of incorrect identification of Indigenous status and the impact of this on hospital statistics.

Results: Cross-validation of HBCIS data with the Indigenous Register over 2 years revealed 355 Indigenous admissions. Of the total 355 admissions, 301 (84.8%) were correctly identified and included in the hospital system, while 22 (6.2%) were designated non-Indigenous, 13 (3.7%) were 'unspecified' and 19 (5.4%) were missed through incorrect residence or admission designation. Among 1293 non-Indigenous admissions, 1.1% were incorrectly identified as Indigenous, while 25.5% of the 51 with unspecified status were found to be Indigenous. Furthermore, 45 Indigenous separations that had been missed over the previous 5 year period (1999/2000 to 2003/2004) were identified through careful examination of all those with unspecified status (n=174) and those with multiple separations of mixed designation of Indigenous status (n=15); all of the latter 15 were confirmed Indigenous by other mental health database and/or the Indigenous Mental Health Worker. Thus overall this study revealed a total of 89 Indigenous separations and 1261 occupied bed days in the 7 year period that had not be identified in the hospital information system.

Conclusion: A novel method was used to ascertain the reliability of Indigenous status identification among mental health admissions within a hospital information system in a region with relatively high Indigenous population representation. This revealed that 85% of admissions were correctly identified over two consecutive years. Perhaps more importantly, the study confirmed a low frequency of false identification of non-Indigenous people as Aboriginal and/or Torres Strait Islander. The work has also demonstrated the value of involving Indigenous Mental Health Workers in routine processes to enhance, validate and improve Indigenous statistics and increase access to culturally informed care.