Descriptive statistics of patients in the validation cohort and patients lost to follow-up
| Characteristics | Validation cohort n=1061 | Lost to follow-up n=15 |
| Age (years) | ||
| Median (Q1;Q3) | 31 (26;35) | 33 (29;36) |
| Range | 15–49 | 20–44 |
| First hCG value (IU/L) | ||
| Median (Q1;Q3) | 703 (210;2312) | 640 (272;6325) |
| Range | 7–180 000 | 19–2800 |
| Second hCG value (IU/L) | ||
| Median (Q1;Q3) | 635 (150;2700) | 810 (120:8100) |
| Range | 1–180 000 | 21–3500 |
| hCG ratio (second hCG/first hCG) | ||
| Median (Q1;Q3) | 0.94 (0.45;1.59) | 1.1 (0.79;1.53) |
| Range | 0.06–5.65 | 0.23–1.79 |
| Hours between two hCG samples, n (%) | ||
| <24 | 0 (0) | 0 (0) |
| 24–39 | 141 (13) | 2 (13) |
| 40–56 | 751 (71) | 7 (47) |
| 57–72 | 169 (16) | 3 (20) |
| >72 | 0 (0) | 0 (0) |
| Type of PUL, n (%) | ||
| True PUL | 793 (75) | 11 (73) |
| Probable IUP | 239 (22) | 4 (27) |
| Probable EP | 29 (3) | 0 (0) |
| Vaginal bleeding, n (%) | 723 (68) | 8 (53) |
| Prior ectopic pregnancy, n (%) | 76 (7) | 1 (6) |
| IUD, n (%) | 30 (3) | 0 (0) |
Because of rounding the summarised percentage sometimes are not exactly 100%.
EP, ectopic pregnancy; hCG, human chorionic gonadotropin; IUD, intrauterine device; IUP, intrauterine pregnancy; PUL, pregnancy of unknown location; Q1, first interquartile; Q3, third interquartile.