Figure 1.
Figure 2.
Figure 3.
Predictive Performance of Risk Score at Various Thresholds_
| Threshold (Score ≥) | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | LR+ | LR− | Accuracy |
|---|---|---|---|---|---|---|---|
| ≥ 1 point | 100.0% (88.4 – 100.0) | 35.7% (24.6 – 48.1) | 36.6% (27.0 – 47.2) | 100.0% (86.3 – 100.0) | 1.56 | 0.00 | 56.0% |
| ≥ 3 points | 96.7% (82.8 – 99.9) | 77.1% (65.6 – 86.3) | 65.9% (50.1 – 79.5) | 98.1% (89.7 – 100.0) | 4.22 | 0.04 | 84.0% |
| ≥ 6 points | 70.0% (50.6 – 85.3) | 88.6% (78.7 – 94.9) | 75.0% (55.1 – 89.3) | 86.1% (75.9 – 93.4) | 6.13 | 0.34 | 84.0% |
| ≥ 9 points | 16.7% (5.6 – 34.7) | 100.0% (94.9 – 100.0) | 100.0% (47.8 – 100.0) | 76.0% (66.4 – 84.2) | ∞ | 0.83 | 80.0% |
Clinical Risk Score Components and Point Allocation_
| Predictor | Scoring Rule | Point Range | Example |
|---|---|---|---|
| Maternal age (>25 years) | +1 point per 4-year increment above 25 (max 2 points) | 0 – 2 | Age 33 → 2 points |
| Gravidity (≥2 pregnancies) | +1 point per pregnancy above 1 (capped at 4) | 0 – 4 | Gravida 4 → 3 points |
| Gestational age (<37 wk) | 28–32 wk = 2 pts; 33–36 wk = 1 pt; wk = 0 pts | 0 – 2 | 33 weeks → 1 point |
| Antepartum transfusion | +2 points if present (any transfusion before delivery) | 0 – 2 | Yes (received) → 2 points |
| Total possible score | Sum of all component points (minimum 0, maximum 10) | 0 – 10 | – |
Risk Stratification by Clinical Risk Score_
| Risk Category | Score Range | Patients (n=100) | PPH Cases (n) | PPH Rate % (95% CI) | Predicted Risk Range % |
|---|---|---|---|---|---|
| Low | 0 – 2 | 25 (25.0%) | 1 | 4.0% (0.1 – 20.4) | ~3 – 10% |
| Moderate | 3 – 5 | 42 (42.0%) | 8 | 19.0% (8.6 – 34.1) | ~15 – 30% |
| High | 6 – 8 | 28 (28.0%) | 16 | 57.1% (37.2 – 75.5) | ~40 – 64% |
| Very High | ≥ 9 | 5 (5.0%) | 5 | 100.0% (47.8 – 100.0) | ≥ 75% |
| Total | 0 – 10 | 100 (100%) | 30 | 30.0% (21.2 – 40.1) | – |
Multivariable Logistic Regression Analysis for PPH_
| Predictor | β | SE | Adjusted OR | 95% CI | P-value |
|---|---|---|---|---|---|
| Maternal age (per 1 year) | 0.256 | 0.081 | 1.29 | 1.10 – 1.51 | 0.002 |
| Gravidity (per pregnancy) | 0.746 | 0.378 | 2.11 | 1.00 – 4.43 | 0.049 |
| Gestational age (per week) | −0.446 | 0.201 | 0.64 | 0.44 – 0.94 | 0.021 |
| Antepartum transfusion (yes) | 0.891 | 0.447 | 2.44 | 1.02 – 5.84 | 0.045 |
Baseline Characteristics of the Study Population Stratified by PPH Outcome (N=100) (Values are given as mean ± SD, median (IQR), or number (%) as appropriate)_
| Characteristic | Overall (N=100) | PPH Yes (n=30) | PPH No (n=70) | P-value |
|---|---|---|---|---|
| Maternal factors | ||||
| Age (years) – mean ± SD | 29.3 ± 4.5 | 31.0 ± 3.8 | 28.5 ± 4.6 | <0.001 |
| Gravidity – median (IQR) | 3 (2–4) | 4 (3–5) | 2 (2–3) | 0.008 |
| Hemoglobin at admission (g/dL) – mean ± SD | 9.5 ± 1.3 | 9.5 ± 1.5 | 9.5 ± 1.2 | 0.991 |
| Pregnancy factors | ||||
| Gestational age at delivery (weeks) – mean ± SD | 35.2 ± 2.1 | 33.9 ± 1.8 | 35.8 ± 2.0 | <0.001 |
| Preterm delivery (<37 weeks) – n (%) | 56 (56.0) | 21 (70.0) | 35 (50.0) | 0.067 |
| Care factors | ||||
| <3 antenatal care visits – n (%) | 38 (38.0) | 10 (33.3) | 28 (40.0) | 0.513 |
| Antepartum blood transfusion – n (%) | 32 (32.0) | 23 (76.7) | 9 (12.9) | <0.001 |
| Timing factors | ||||
| Time from onset to admission (hours) – mean ± SD | 5.2 ± 2.8 | 5.8 ± 3.1 | 4.9 ± 2.6 | 0.189 |
| Time from admission to delivery (hours) – mean ± SD | 6.4 ± 3.2 | 6.8 ± 3.5 | 6.2 ± 3.0 | 0.438 |
Model Performance and Internal Validation Metrics_
| Performance Metric | Value | 95% CI |
|---|---|---|
| Discrimination | ||
| AUC (ROC curve) – apparent | 0.86 | 0.80 – 0.92 |
| AUC – optimism-corrected (bootstrap) | 0.84 | 0.78 – 0.90 |
| Calibration | ||
| Calibration slope | 0.95 | – |
| Calibration intercept | 0.02 | – |
| Overall performance | ||
| Nagelkerke R2 | 0.38 | – |
| Brier score | 0.18 | – |
| Internal validation (1000× bootstrap) | ||
| Optimism (AUC) | 0.02 | – |
| Uniform shrinkage factor | 0.93 | – |