Article Text
Abstract
Karasek postulated that high job strain, an interaction between high psychological demands and low control at work, increases the risk of ill-health.
Objective Systematic review/meta-analysis of the association between job strain and blood pressure (BP).
Methods Target studies were published on Pubmed, Lilacs, SciELO, PsycInfo, Embase and Web of Science, until July 2009. Data extraction was conducted independently by 2 of 3 reviewers using a standardised form.
Results The search retrieved 1377 studies and 51 fulfilled the eligibility criteria, mostly cross-sectional and conducted in Europe or USA. Most of them applied the job content questionnaire (89.4%) and used the Karasek's quadrant categories (78.4%). Casual BP was measured in 26 (50%), ambulatory BP monitored in 22 (84.6%), self-measured BP in two (3.8%) and self-reported hypertension in two studies (3.8%). Hypertension was the outcome in 16 studies (30.8%), 9 of them defined by BP>140/90 mm Hg. High strain was associated with high BP/hypertension in 27/51 (52.9%) studies. Meta-analysis could be only performed for nine hypertension studies, for which the association was not confirmed neither for high strain (ORc=1.08, 95% CI 0.98 to 1.19), high psychological demands (ORc=1.08, 95% CI 0.98 to 1.19) nor for high control (ORc=1.02, 95% CI 0.94 to 1.11), with no evidence of publication bias.
Conclusion There is weak evidence in favour of the association between job strain and BP/hypertension. Comparisons were hampered by methods heterogeneity, particularly: inclusion criteria, data collection and exposure/outcome definition. Further research should include longitudinal design, low and middle-income countries and female workers, still lacking.