Table 4.
Separate and joint effects of three semen quality measures on risk of testicular cancer among 29 177 men with some spermatozoa in semen
| Variable | Total No of men | Observed No of cases | Expected No of cases | Standardised incidence ratio (95% CI) |
|---|---|---|---|---|
| Univariate effects | ||||
| Low concentration (⩽20×106/ml) | 10 509 | 33 | 14.5 | 2.3 (1.6 to 3.2)* |
| Poor motility | 1 298 | 7 | 2.8 | 2.5 (1.0 to 5.2)* |
| Many abnormal (>75%) | 528 | 4 | 1.4 | 3.0 (0.8 to 7.6) |
| Separate effects | ||||
| Low concentration (only) | 9 187 | 24 | 11.6 | 2.1 (1.3 to 3.1)* |
| Low motility (only) | 187 | 0 | 0.4 | — |
| Many abnormal (only) | 213 | 0 | 0.6 | — |
| Other | 19 590 | 52 | 39.5 | 1.3 (1.0 to 1.7) |
| Joint effects | ||||
| One subfertility measure | 9 587 | 24 | 12.6 | 1.9 (1.2 to 2.8)* |
| Two subfertility measures | 1 251 | 7 | 2.6 | 2.7 (1.1 to 5.5)* |
| Three subfertility measures | 82 | 2 | 0.2 | 9.3 (1.0 to 33.4) |
| Other | 18 257 | 43 | 36.7 | 1.2 (0.9 to 1.6) |
*
P<0.05.