The psychometric properties of Karasek's demand and control scales within a single sector: data from a large teaching hospital.
OBJECTIVE
This paper reviews the psychometric properties of the core components from Karasek's job content questionnaire, the decision latitude and psychological job demands scales.


METHODS
A self-reported survey was administered in 1995 (time 1), 1996 (time 2), and 1997 (time 3) to employees of a large teaching hospital. Analyses for this paper are based on data from the 484 employees who responded at times 1 and 2.


RESULTS
Both scales demonstrated acceptable internal consistency as assessed by item-total correlations and Cronbach's alpha. In confirmatory factor analysis, the two-factor decision latitude model adequately fit the data. However, our findings suggest that a two-factor model may provide an improved fit over the original one-factor demands model, suggesting that this scale may be two distinct subscales. Lastly, the scales demonstrated acceptable discriminant validity.


CONCLUSIONS
Apart from some guarded uncertainty over what the demands scale may be measuring, overall, the two scales appeared to perform reasonably well in this sample of health care workers.
Sale
Joanna E M
JE
Institute for Work & Health, Toronto, Ontario, Canada. jsale@iwh.on.ca
Kerr
Michael S
MS
D000328:Adult; D003657:Decision Making; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007389:Internal-External Control; D007588:Job Satisfaction; D008297:Male; D008875:Middle Aged; D009864:Ontario; D010564:Personnel, Hospital / Q000523:psychology*; D011594:Psychometrics; D013315:Stress, Psychological; D011795:Surveys and Questionnaires; D013647:Task Performance and Analysis; D000078329:Workforce; D016526:Workload / Q000523:psychology*