Post-discharge surgical wound infection surveillance in a provincial hospital: Follow-up rates, validity of data and review of the literature

Background: Numerous studies suggest that many surgical site infections (SSI) come to light only after discharge from hospital. With increasing trends towards shorter length of stay and ambulatory day surgery, post-discharge surveillance may become necessary for all infection control programs, but the methodology has yet to be validated and standardized. The overall aim of the present study was to examine the impact of effective post-discharge SSI follow up on the overall SSI rate. Methods: A prospective targeted surveillance programme of 1291 surgical procedures was conducted at St John of God Health Care Geelong using the standardized National Nosocomial Infections Surveillance (NNIS) method. Questionnaires were sent to surgeons and the results rigorously chased up. Factors giving rise to high follow-up rates and the relationship between follow up, attrition bias and validity of data were explored using a literature search. Results: A post-discharge follow-up rate of 98.7% was achieved. When the post-discharge data were included, the overall SSI rate (6.0% (95% CI: 4.7-7.4)) was more than double that in hospital (2.7% (95% CI: 1.9-3.8)). Conclusions: An effective post-discharge follow-up programme significantly increased the SSI rate. From the authors' experience and a literature survey, possible ways to achieve high follow-up rates were suggested. It was also recommended that professional and regulating bodies in Australia be encouraged to standardize methodology and set minimum follow-up rates for post-discharge SSI surveillance. Increasing use of computerized hospital database systems for automated data gathering and processing should make this more practicable.