Validation of healthcare-associated Staphylococcus aureus bloodstream infection surveillance in Western Australian public hospitals

The rate of healthcare-associated Staphylococcus aureus bacteraemia (HA-SAB) is one outcome measure utilised to assess the quality and safety of care provided in hospitals. It has been accepted for use for this purpose by the Australian Health Ministers Council and has been incorporated as an indicator into the National Healthcare Agreement. To ensure such data is credible, it is critical that all organisations with responsibility for collating and analysing HA-SAB rates have systems in place to support accurate data collection at the hospital level, regularly review and improve these systems, and perform quality assurance of the data they receive and submit to the Commonwealth. To assess the quality of data being submitted to Healthcare Infection Surveillance Western Australian (HISWA), a retrospective audit was performed to validate 2008 HA-SAB data submitted by Western Australian public hospitals. The sensitivity of HISWA HA-SAB surveillance was 77% and the specificity was 99.6%. Hospitals without on-site clinical microbiologists performed relatively poorly. Discharge coding was not an accurate reflection of SAB rates.