TABLE 4.

Age-Group Stratified Multivariate Cox Proportional Hazards Models and 95% Confidence Intervals (CIs) for Acute Myocardial Infarction (MI) at Baseline and at 4-Year Follow-Up: Still Working Study, Finland, January 1, 1987, to December 31, 2004

	Employees Aged 18–44 y	Employees Aged 45–54 y	Pa
Population at baseline
Population (no. of acute MIs)	5055 (133)	2189 (196)
Work characteristic, HR (95% CI)
Skill discretion	1.11 (0.90, 1.33)	1.14 (0.95, 1.35)	.61
Decision authority	0.96 (0.79, 1.16)	1.12 (0.97, 1.31)	.23
Predictability	1.00 (0.84, 1.20)	1.24 (1.07, 1.43)	.06
Population after 4 y
Population (no. of acute MIs)	5025 (127)	2152 (171)
Work characteristic, HR (95% CI)
Skill discretion	1.11 (0.94, 1.43)	1.13 (0.93, 1.36)	.77
Decision authority	0.99 (0.82, 1.20)	1.15 (0.98, 1.35)	.32
Predictability	1.00 (0.83, 1.21)	1.25 (1.07, 1.46)	.09

Note. HR = hazard ratio. Adjusted for continuous age, gender, marital status, prevalent hypertension, prevalent diabetes, psychological distress, smoking status, alcohol use, physical activity, occupational status, and educational attainment at baseline.

^aTest for age group interaction.