title: The assessment of publication pressure in medical science; validity and reliability of a Publication Pressure Questionnaire (PPQ).
abstract: OBJECTIVE
  To determine content validity, structural validity, construct validity and reliability of an internet-based questionnaire designed for assessment of publication pressure experienced by medical scientists.
  
  
  METHODS
  The Publication Pressure Questionnaire (PPQ) was designed to assess psychological pressure to publish scientific papers. Content validity was evaluated by collecting independent comments from external experts (n = 7) on the construct, comprehensiveness and relevance of the PPQ. Structural validity was assessed by factor analysis and item response theory (IRT) using the generalized partial credit model. Pearson's correlation coefficients were calculated to assess potential correlations with the emotional exhaustion and depersonalization subscales of the Maslach Burnout Inventory (MBI). Single test reliability (lambda2) was obtained from the IRT analysis.
  
  
  RESULTS
  Content validity was satisfactory. Confirmatory factor analysis did not support the presence of three initially assumed separate domains of publication pressure (i.e., personally experienced publication pressure, publication pressure in general, pressure on position of scientist). After exclusion of the third domain (six items), we performed exploratory factor analysis and IRT. The goodness-of-fit statistics for the IRT assuming a single dimension were satisfactory when four items were removed, resulting in 14 items of the final PPQ. Correlations with the emotional exhaustion and depersonalization scales of the MBI were 0.34 and 0.31, respectively, supporting construct validity. Single test administration reliability lambda2 was 0.69 and 0.90 on the test scores and expected a posteriori scores, respectively.
  
  
  CONCLUSIONS
  The PPQ seems a valid and reliable instrument to measure publication pressure among medical scientists.
authors: Department of Internal Medicine, VU University Medical Centre, PO Box 7057, 1007 MB, Amsterdam, The Netherlands, j.tijdink@vumc.nl.
authors: J K
authors: JK
authors: Tijdink
authors: Y M
authors: YM
authors: Smulders
authors: A C M
authors: AC
authors: Vergouwen
authors: H C W
authors: HC
authors: de Vet
authors: D L
authors: DL
authors: Knol
mesh_terms: D000328:Adult; D000368:Aged; D001319:Authorship; D035843:Biomedical Research; D002055:Burnout, Professional / Q000175:diagnosis / Q000209:etiology; D005180:Faculty, Medical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D013315:Stress, Psychological / Q000175:diagnosis* / Q000209:etiology; D011795:Surveys and Questionnaires