In this issue of the Journal of Neurosurgery: Pediat rics, Dr. Parker and colleagues summarize the literature on antibiotic impregnated shunts (AISs). Using a systematic literature review, they identify 12 cohorts that directly compare AISs versus non-AISs. Five of these are for pediatric hydrocephalus, 3 for adult hydrocephalus, and 4 included mixed populations. They have identified a large number of shunt procedures (5613) and report a reduction in shunt infection using AIS catheters in the entire study and separately in pediatric and adult subpopulations.6 At first glance, these are impressive data. The large number of shunt procedures and the reduced infection rates seem to support the efficacy of AISs. The methods of the systematic review are well done, but there is room for improvement before we accept the conclusions. A well-done systematic review of high-quality randomized trials is one of our best sources of evidence for making treatment decisions. There is extensive literature on the methods used to produce a high-quality systematic review. I will refer to the main points in discussing Dr. Parker’s work.