Model performance comparison for original validation study and new validation in immigrant and non-immigrant subgroups
| Cohort | RMSE (wks) | Infants with GA correctly classified | |||||||||
| Overall | ≥37 wks | 32–<37 wks | 28–<32 wks | <28 wks | |||||||
| ±1 wks (%) | ±2 wks (%) | ±1 wks (%) | ±2 wks (%) | ±1 wks (%) | ±2 wks (%) | ±1 wks (%) | ±2 wks (%) | ±1 wks (%) | ±2 wks (%) | ||
| Original validation | 1.06 | 66.8 | 94.9 | 69.1 | 96.4 | 39.0 | 75.6 | 46.5 | 76.9 | 50.7 | 77.5 |
| Validation based on immigration status in IRCC | |||||||||||
| New validation cohort (overall) | 1.04 | 67.1 | 95.0 | 69.2 | 96.4 | 40.1 | 76.3 | 48.6 | 78.5 | 48.2 | 79.0 |
| Non-immigrants | 1.05 | 67.0 | 94.9 | 69.1 | 96.4 | 39.8 | 76.2 | 48.4 | 78.43 | 49.39 | 79.18 |
| All immigrants | 1.04 | 67.7 | 95.2 | 69.6 | 96.4 | 41.4 | 76.9 | 49.5 | 78.9 | 44.7 | 82.3 |
| India | 1.04 | 68.1 | 95.2 | 69.8 | 96.3 | 44.4 | 80.0 | 42.0 | 70.0 | 42.9 | 85.7 |
| China | 0.98 | 71 | 96.2 | 72.9 | 97.6 | 31.4 | 67.4 | 51.7 | 75.9 | 20.0 | 80.0 |
| Pakistan | 1.05 | 67.2 | 95.3 | 68.4 | 96.2 | 48.7 | 82.2 | 61.5 | 88.5 | 62.5 | 87.5 |
| Philippines | 1.05 | 66.5 | 94.7 | 69.1 | 96.6 | 34.8 | 70.9 | 57.1 | 91.4 | 45.4 | 100.0 |
| Vietnam | 1.00 | 70.0 | 95.2 | 72.4 | 96.7 | 34.2 | 70.9 | 40.0 | 100.0 | 0.0 | 100.0 |
| Bangladesh | 1.14 | 67.4 | 94.6 | 69.1 | 95.9 | 45.1 | 77.5 | 44.4 | 77.8 | 60.0 | 80.0 |
| Somalia | 1.15 | 62.1 | 93.6 | 64.6 | 95.7 | 26.4 | 64.2 | 33.3 | 66.7 | 50.0 | 100.0 |
| Nigeria | 1.08 | 65.1 | 94.6 | 66.7 | 95.7 | 75.0 | 80.8 | 75.0 | 75.0 | 40.0 | 80.0 |
GA, gestational age; IRCC, Citizenship and Immigration Canada’s Permanent Resident Database; RMSE, root mean squared error; wks, weeks.