title: Clinical equipoise in idiopathic normal pressure hydrocephalus: a survey of physicians on the need for randomized controlled trials assessing the efficacy of cerebrospinal fluid diversion.
abstract: BACKGROUND
  Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome that may be reversible by diversion of cerebrospinal fluid (CSF). It is increasingly recognized, and accordingly rates of CSF diversion are increasing despite the absence of level I evidence of efficacy, non-neglible rate of complications and an unclear natural history.
  
  
  METHODS
  A total of 349 neurosurgeons, neurologists, geriatricians and neuropsychiatrists rated the perceived efficacy of CSF diversion, the duration of effect of CSF diversion, and the risk-benefit ratio of CSF diversion in iNPH. These physicians then rated the need for a randomized controlled trial (RCT) of CSF diversion in iNPH. Participants detailed their desired selection criteria and supportive testing for a RCT, and their preferred control group.
  
  
  RESULTS
  Physicians believe that there is uncertain efficacy of CSF diversion in iNPH, as well as the expected duration of this benefit and the risk-benefit ratio for patients. The greatest degree of uncertainty related to the long-term benefit of surgery. Accordingly, over 75% desire a RCT to determine the efficacy of CSF diversion in iNPH. Only 2.7% of participants believe a RCT of CSF diversion in iNPH is unethical. Patients without a shunt and a programmable valve in the 'off' setting were the preferred control groups.
  
  
  CONCLUSIONS
  A RCT of CSF diversion in iNPH is absent from the literature. The majority (>75%) of physicians involved in the diagnosis and treatment of iNPH believe a RCT is required to determine the efficacy, duration of efficacy and risk-benefit ratio of CSF diversion in iNPH.
authors.affiliation: Injury Prevention Research, St-Michael's Hospital, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of British Columbia, Vancouver, Canada. Electronic address: Alexander.mcgirr@alum.utoronto.ca.
authors.forename: Alexander
authors.initials: A
authors.lastname: McGirr
authors.forename: Safraz
authors.initials: S
authors.lastname: Mohammed
authors.forename: Roger
authors.initials: R
authors.lastname: Kurlan
authors.forename: Michael D
authors.initials: MD
authors.lastname: Cusimano
mesh_terms: D001291:Attitude of Health Personnel; D002557:Cerebrospinal Fluid Shunts; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000601:surgery*; D008875:Middle Aged; D010820:Physicians; D016032:Randomized Controlled Trials as Topic; D057212:Therapeutic Equipoise
keywords: CSF diversion; Control group; Normal pressure hydrocephalus; Randomized controlled trial; Shunting; Survey