Job control, perceptions of control, and cardiovascular activity: an analysis of ambulatory measures collected over the working day.
OBJECTIVE
To assess the influence of job control as a personal characteristic, and momentary perceptions of lack of control, on blood pressure and heart rate monitored over the working day.


METHODS
The study was carried out with a sample of 122 school teachers (45 men, 77 women), divided into high and low job control groups on a standard questionnaire. Blood pressure and heart rate were measured every 20 min using ambulatory techniques, and ratings of concurrent perceived control were also obtained. Energy expenditure was assessed using accelerometers. Cardiovascular measures associated with low perceived control were averaged for each individual, as were readings associated with high perceived control.


RESULTS
Low perceived control ratings were infrequent overall. However, in the participants who reported episodes of both high and low perceived control, systolic and diastolic blood pressure and heart rate were significantly greater during episodes of low control. These effects were independent of concurrent energy expenditure, gender, and time of day. High and low job control groups did not differ in cardiovascular responses to episodes of low perceived control. But low job control was associated with more frequent episodes of low perceived control and fewer periods of high perceived control.


CONCLUSIONS
The results suggest that laboratory observations concerning the impact of lack of control on cardiovascular activity are corroborated by naturalistic measures in everyday life. Differences in exposure to periods of low perceived control rather than differences in reactivity to uncontrollable situations may contribute to the elevation in cardiovascular risk associated with low job control.
Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, WC1E 6BT, London, UK. a.steptoe@ucl.ac.uk
A
A
Steptoe
D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007389:Internal-External Control; D007588:Job Satisfaction; D008297:Male; D010465:Perception