title: The prevalence of shunt-treated hydrocephalus: a mathematical model.
abstract: BACKGROUND
  The aim of the study was to create a mathematical model that reproduces the prevalence of shunt-treated hydrocephalus in the United States over the years and predicts trends in the near future.
  
  
  METHODS
  A structured search was performed of the English language literature for case series reporting rates of shunt insertion and revision, shunt removal, and patient mortality. A meta-analytic model was constructed to pool data from multiple studies and to calculate these rates at various time intervals. Separate Markov models were used to predict numbers of shunts at any one time for children (<17 years old) and adults. The models analyze the number of shunts inserted every year since 1955 and follow the likely fates of those patients as time passes.
  
  
  RESULTS
  Prevalence rates predicted by the model agree closely with those reported in the literature. However, the model's structure creates considerable variability around point estimates.
  
  
  CONCLUSIONS
  The model gives a comprehensive view of the prevalence of shunt-treated hydrocephalus in both children and adults from 1955 to the present. This model may prove useful in predicting resource use and needs for patients with hydrocephalus.
authors.affiliation: Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. sherman.stein@uphs.upenn.edu
authors.forename: Sherman C
authors.initials: SC
authors.lastname: Stein
authors.forename: Wensheng
authors.initials: W
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D002557:Cerebrospinal Fluid Shunts / Q000401:mortality* / Q000706:statistics & numerical data*; D002648:Child; D002675:Child, Preschool; D020878:Device Removal / Q000706:statistics & numerical data; D004868:Equipment Failure / Q000706:statistics & numerical data; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery*; D007223:Infant; D007231:Infant, Newborn; D008390:Markov Chains; D015233:Models, Statistical; D015995:Prevalence; D012086:Reoperation / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology