title: Does response propensity bias stress audits?
abstract: BACKGROUND
  Non-response bias in surveys occurs when non-respondents differ from respondents. Methods of dealing with this include measuring 'response propensity'. We propose that response propensity has a trait-like component, measurable within the survey. Covariance of this component with survey items could indicate non-response bias.
  
  
  OBJECTIVE
  To measure and validate trait-like response propensity, to test whether it co-varied with survey items during a routine stress audit and to test whether a prior staff attitude survey may have been biased.
  
  
  METHODS
  Stress survey sent to government employees during a routine audit. We designed two new items to measure trait-like response propensity and completion of a prior staff survey. We calculated an odds ratio, correlations and Mann-Whitney U-tests to assess relationships between trait response propensity, completion of the prior staff survey and current stress survey scores.
  
  
  RESULTS
  There were 71 respondents; response rate 68%. The trait response propensity item predicted completion of a prior staff survey (odds ratio 8.75, 95% confidence interval 2.32-33.08). Trait response propensity significantly correlated with two of the 40 survey items and did not significantly correlate with any of the eight 'stressor' sub-scales. Non-respondents to the prior staff survey had a significantly lower risk of stress on two of the eight stressor scales.
  
  
  CONCLUSIONS
  Trait response propensity seems to be a valid construct. The weight of evidence does not provide an indication of non-response bias (yet neither does it assure freedom from non-response bias). The prior staff survey may have been affected by non-response bias.
authors.affiliation: Human Factors Department, Institute of Naval Medicine, Alverstoke PO12 2DL, UK. Bob.Bridger300@mod.uk.
authors.forename: R S
authors.initials: RS
authors.lastname: Bridger
authors.affiliation: Human Factors Department, Institute of Naval Medicine, Alverstoke PO12 2DL, UK.
authors.forename: I
authors.initials: I
authors.lastname: Fisher
authors.affiliation: Human Factors Department, Institute of Naval Medicine, Alverstoke PO12 2DL, UK.
authors.forename: K
authors.initials: K
authors.lastname: Dobson
authors.affiliation: Human Factors Department, Institute of Naval Medicine, Alverstoke PO12 2DL, UK.
authors.forename: S C
authors.initials: SC
authors.lastname: Wattie
mesh_terms: D001290:Attitude; D015982:Bias; D004651:Employment; D006076:Government; D006801:Humans; D009784:Occupational Diseases / Q000209:etiology / Q000523:psychology; D016273:Occupational Exposure / Q000009:adverse effects; D009790:Occupations; D015203:Reproducibility of Results; D013315:Stress, Psychological / Q000209:etiology; D011795:Surveys and Questionnaires / Q000592:standards*; D014937:Work / Q000523:psychology*
keywords: Non-response bias; occupational stress; questionnaire surveys.