title: Procedures that assess inconsistency in meta-analyses can assess the likelihood of response bias in multiwave surveys.
abstract: OBJECTIVE
  Response bias may affect the result of surveys with <100% response rate. We applied methods commonly used in meta-analysis to ascertain the extent to which response bias affects multiwave survey results.
  
  
  METHODS
  To test hypotheses of between-wave similarity, we used the Cochran-Armitage test for trends and the Q-test of heterogeneity across waves in a survey of 2,127 North American clinicians using six e-mail waves and one fax wave and achieving a response rate of 22%. We used the I2 statistic To quantify the extent of inconsistency in survey outcomes across waves not due to within-wave random error (i.e., inconsistency due to response bias).
  
  
  RESULTS
  With this survey, tests of heterogeneity and trend were not significant and I2 equaled 0%. These results suggest that the underlying responses did not differ across waves and thus strengthened the inference that response bias was not affecting the interpretation of the survey.
  
  
  CONCLUSIONS
  Researchers can use procedures that assess inconsistency in meta-analyses to evaluate the validity of a multiwave survey with a less than optimal response rate.
authors: Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors: Victor M
authors: VM
authors: Montori
authors: Teresa W
authors: TW
authors: Leung
authors: Stephen D
authors: SD
authors: Walter
authors: Gordon H
authors: GH
authors: Guyatt
mesh_terms: D015982:Bias; D003299:Cooperative Behavior; D034742:Electronic Mail; D019538:Health Care Surveys / Q000379:methods*; D006801:Humans; D015201:Meta-Analysis as Topic; D015203:Reproducibility of Results; D016636:Telefacsimile