Table 1 Distribution of test results in the full study population and the nested case-control samples with various case-control ratios
From: Advantages of the nested case-control design in diagnostic research
| Full study population | Nested case-control samples for different case-control ratios | ||||||
|---|---|---|---|---|---|---|---|
| DVT + | DVT- | Cases | Controls | ||||
| Test results | n = 289 | n = 1006 | n = 289 |
1:1 n = 289 |
1:2 n = 578 |
1:3 n = 867 |
1:4 n = 1156 |
| D-dimer test abnormal | 271 (94) | 621 (62) | 271 (94) | 178 (61) | 357 (62) | 535 (62) | 713 (62) |
| Calf difference, cm* | 3.2 (1.7) | 2.1 (1.6) | 3.2 (1.7) | 2.1 (1.6) | 2.1 (1.6) | 2.1 (1.6) | 2.1 (1.6) |
| Age, years* | 61.9 (16.8) | 59.4 (17.7) | 61.9 (16.8) | 59.4 (17.8) | 59.5 (17.8) | 59.4 (17.8) | 59.4 (17.7) |
| Male gender | 137 (47) | 330 (33) | 137 (47) | 94 (33) | 190 (33) | 282 (33) | 380 (33) |
