Ms Michelle Stirling1, Ms Simone Tempone1, Ms Rebecca McCann1
1Department Of Health, East Perth, Australia
Healthcare Infection Surveillance Western Australia (HISWA) is a state-wide surveillance program for monitoring healthcare associated infection data, including surgical site infections (SSI) following hip and knee arthroplasty. All hospitals performing these procedures in Western Australia (WA) submit data to HISWA.
In July 2014 the surveillance period for deep SSI following arthroplasty was reduced from 365 to 90 days. Retrospective data were not amended to reflect the change.
To measure the effect of a reduced surveillance period on reported SSI rates in WA.
All SSIs reported to HISWA from 1st July 2009 to 30 June 2019 were included in this study. Comparison of median time to infection, and SSI rates pre and post-definition change was performed. Data is to be further interrogated to identify any significant changes in patient and infection information.
The five year pre-definition change (to July 2014) SSI rate for hip and knee arthroplasty was 1.26 and 1.09 infections per 100 procedures respectively, and median time to infection was 19 and 21 days, respectively. Preliminary post-definition change (from July 2014) SSI rate for hip and knee arthroplasty was 0.78 and 0.56 infections per 100 procedures respectively, and median time to infection was 23 days for both procedures.
There was a statistically significant reduction (p<0.05) in both hip and knee SSI rates between the pre and post definition change years. These data will be further explored.
Caution needs to be taken when interpreting longitudinal HISWA SSI data due to this definition change.