title: Estimating the incidence of symptomatic rotavirus infections: a systematic review and meta-analysis.
abstract: BACKGROUND
  We conducted for the first time a systematic review, including a meta-analysis, of the incidence of symptomatic rotavirus (RV) infections, because (1) it was shown to be an influential factor in estimating the cost-effectiveness of RV vaccination, (2) multiple community-based studies assessed it prospectively, (3) previous studies indicated, inconclusively, it might be similar around the world.
  
  
  METHODS
  Pubmed (which includes Medline) was searched for surveys assessing prospectively symptomatic (diarrheal) episodes in a general population and situation, which also reported on the number of the episodes being tested RV+ and on the persons and the time period observed. A bias assessment tool was developed and used according to Cochrane guidelines by 4 researchers with different backgrounds. Heterogeneity was explored graphically and by comparing fits of study-homogenous 'fixed effects' and -heterogeneous 'random effects' models. Data were synthesized using these models. Sensitivity analysis for uncertainty regarding data abstraction, bias assessment and included studies was performed.
  
  
  RESULTS
  Variability between the incidences obtained from 20 studies is unlikely to be due to study groups living in different environments (tropical versus temperate climate, slums versus middle-class suburban populations), nor due to the year the study was conducted (from 1967 to 2003). A random effects model was used to incorporate unexplained heterogeneity and resulted in a global incidence estimate of 0.31 [0.19; 0.50] symptomatic RV infections per personyear of observation for children below 2 years of age, and of 0.24 [0.17; 0.34] when excluding the extreme high value of 0.84 reported for Mayan Indians in Guatemala. Apart from the inclusion/exclusion of the latter study, results were robust.
  
  
  CONCLUSIONS
  Rather than assumptions based on an ad-hoc selection of one or two studies, these pooled estimates (together with the measure for variability between populations) should be used as an input in future cost-effectiveness analyses of RV vaccination.
authors: Centre for Health Economics Research & Modeling of Infectious Diseases (CHERMID), Vaccine and Infectious Disease Institute (VAXINFECTIO), University of Antwerp, Wilrijk, Antwerp, Belgium. joke.bilcke@ua.ac.be
authors: Joke
authors: J
authors: Bilcke
authors: Pierre
authors: P
authors: Van Damme
authors: Marc
authors: M
authors: Van Ranst
authors: Niel
authors: N
authors: Hens
authors: Marc
authors: M
authors: Aerts
authors: Philippe
authors: P
authors: Beutels
mesh_terms: D003141:Communicable Diseases / Q000453:epidemiology; D003362:Cost-Benefit Analysis; D014943:Global Health; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D011446:Prospective Studies; D012306:Risk; D012401:Rotavirus / Q000378:metabolism*; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000821:virology*; D013997:Time Factors; D016896:Treatment Outcome