Table 1.
Comparison of the historical study sample (n = 839) with the rest of the Kuopio Ischaemic Risk Factor study (KIHD) cohort (n = 1472).
| Covariates | Mean (SD) or proportion (%) | ||
|---|---|---|---|
| Historical study sample (n = 839) | The rest of the KIHD cohort (n = 1472) | P values for the difference between groups | |
| Age group (%) | |||
| (1) (42 years) | 24.7 | 6.7 | <0.001 |
| (2) (48 years) | 19.9 | 10.0 | |
| (3) (54 years) | 44.8 | 66.4 | |
| (4) (60 years) | 10.6 | 16.9 | |
| Educational level (%) | |||
| (1) less than elementary | 7.5 | 11.1 | <0.001 |
| (2) elementary | 42.6 | 49.5 | |
| (3) full or some secondary | 42.8 | 31.9 | |
| (4) high school or above | 7.2 | 7.4 | |
| Occupational level (%) | |||
| (1) farmer | 11.7 | 17.8 | <0.001 |
| (2) blue collar | 45.8 | 42.1 | |
| (3) white collar | 42.6 | 40.2 | |
| Smoking history (pack/years) | 163.7 (299.6) | 200.7 (377.2) | 0.011 |
| BMI (kg/m2) | 26.8 (3.6) | 26.9 (3.5) | 0.604 |
| LDL cholesterol (mmol/L) | 4.0 (1.0) | 4.1 (1.0) | 0.008 |
| HDL cholesterol (mmol/L) | 1.3 (0.3) | 1.3 (0.3) | 0.424 |
| SBP (mm Hg) | 133.5 (16.3) | 134.5 (17.1) | 0.198 |
| Leisure time physical activity (h/year) | 123.5 (153.8) | 106.7 (129.7) | 0.008 |
| Alcohol consumption (g/week) | 92.7 (151.7) | 85.9 (139.2) | 0.281 |
| Income (marks/year) | 83,983.2 (54174.6) | 77,512.3 (52398.8) | 0.005 |
BMI: body mass index; LDL: low density lipoprotein; HDL: high density lipoprotein; SBP: systolic blood pressure.