Decreased risk of infection in cerebrospinal fluid shunt surgery using prophylactic antibiotics: a case-control study.

Four randomised controlled trials have focussed on the use of prophylactic antibiotics in the prevention of cerebrospinal fluid (CSF) shunt infection. None of these studies has been able to demonstrate a statistically significant difference in rate of infection. This may be due to the inadequate power of the studies to detect a clinically significant difference, as a result of small sample size. This retrospective case control study was designed using the same basic principles of avoidance of bias which make randomised controlled trials the model studies for generation of scientific evidence. It has found a highly statistically significant difference in the use of antibiotics among infected compared to non-infected patients, suggesting a three times greater risk of infection among patients who did not receive antibiotics. This study provides the strongest evidence to date regarding the usefulness of perioperative antibiotics in CSF shunt surgery.