Individual and work-unit measures of psychological demands and decision latitude and the use of antihypertensive medication.

PURPOSE: To analyse whether psychological demands and decision latitude measured on individual and work-unit level were related to prescription of antihypertensive medication.
METHODS: A total of 3,421 women and 897 men within 388 small work units completed a questionnaire concerning psychological working conditions according to the job strain model. Mean levels of psychological demands and decision latitude were computed for each work unit to obtain exposure measures that were less influenced by reporting bias. Dispensed antihypertensive medication prescriptions were identified in The Danish National Prescription Registry. Odds ratios (OR) comparing the highest and lowest third of the population at individual and work-unit level, respectively, were estimated by multilevel logistic regression adjusted for confounders. Psychological demands and decision latitude were tested for interaction. Supplementary analyses of 21 months follow-up were conducted.
RESULTS: Among women, increasing psychological demands at individual (adjusted OR 1.54; 95 % CI 1.02-2.33) and work-unit level (adjusted OR 1.41; 95 % CI 1.04-1.90) was significantly associated with purchase of antihypertensive medication. No significant association was found for decision latitude. Follow-up results supported an association with psychological demands but they were not significant. All results for men showed no association. Psychological demands and decision latitude did not interact.
CONCLUSION: High psychological work demands were associated with the purchase of prescribed antihypertensive medication among women. This effect was present on both the work-unit and the individual level. Among men there were no associations. The lack of interaction between psychological demands and decision latitude did not support the job strain model.