HRs (95% CI) for all-cause mortality according to quartiles of intellectual ability test scores and father's occupational status
| Number of deaths/subjects | Manual worker | Number of deaths/subjects | Middle class | |
| Verbal | ||||
| Lowest | 99/501 | 2.1 (1.4 to 3.0) | 27/140 | 2.1 (1.3 to 3.4) |
| 2 | 100/515 | 2.0 (1.4 to 2.9) | 32/203 | 1.6 (1.0 to 2.6) |
| 3 | 64/391 | 1.7 (1.2 to 2.6) | 25/256 | 1.0 (0.6 to 1.7) |
| Highest | 36/314 | 1.3 (0.8 to 2.0) | 39/414 | 1.0 (Referent) |
| Per 1 unit lower test z score | 1.16 (1.02 to 1.30) | 1.38 (1.16 to 1.65) | ||
| Adjusted for educational attainment | 1.07 (0.94 to 1.22) | 1.29 (1.05 to 1.59) | ||
| Visuospatial | ||||
| Lowest | 98/506 | 3.1 (1.9 to 5.1) | 33/155 | 3.5 (2.0 to 6.2) |
| 2 | 84/425 | 3.2 (1.9 to 5.2) | 31/194 | 2.7 (1.5 to 4.7) |
| 3 | 80/490 | 2.6 (1.6 to 4.3) | 39/346 | 1.8 (1.0 to 3.1) |
| Highest | 37/300 | 2.0 (1.1 to 3.4) | 21/319 | 1.0 (Referent) |
| Per 1 unit lower test z score | 1.17 (1.04 to 1.31) | 1.53 (1.29 to 1.81) | ||
| Adjusted for educational attainment | 1.08 (0.95 to 1.22) | 1.47 (1.21 to 1.79) | ||
| Arithmetic | ||||
| Lowest | 106/523 | 2.5 (1.6 to 3.8) | 32/161 | 2.6 (1.5 to 4.3) |
| 2 | 80/459 | 2.2 (1.4 to 3.4) | 28/207 | 1.7 (1.0 to 2.8) |
| 3 | 68/427 | 2.0 (1.3 to 3.2) | 34/286 | 1.6 (0.9 to 2.6) |
| Highest | 42/302 | 1.7 (1.1 to 2.8) | 29/356 | 1.0 (Referent) |
| Per 1 unit lower test z score | 1.13 (1.00 to 1.26) | 1.36 (1.13 to 1.63) | ||
| Adjusted for educational attainment | 1.03 (0.91 to 1.16) | 1.23 (0.99 to 1.53) | ||
p for interaction between childhood socioeconomic status and intellectual ability scores 0.06 for verbal test score, 0.002 for visuospatial test score and 0.02 for arithmetic test score, adjusted for age, year, height and body mass index and testing and childhood socioeconomic status.
Analyses are stratified for year of birth and adjusted for age, year, height and body mass index and testing and childhood socioeconomic status.