US-CDC’s SMM | P-value | Gold standard guideline for SMM | P-value | Zwart’s SMM | P-value | EURONET-SAMM | P-value | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
RR | 95% CI | RR | 95% CI | RR | 95% CI | RR | 95% CI | |||||||||
Individual factors | ||||||||||||||||
Maternal age (y) | ||||||||||||||||
15–19 | 1.35 | 1.25 | 1.45 | < .0001 | 1.27 | 1.19 | 1.36 | < .0001 | 0.85 | 0.64 | 1.13 | 0.277 | 1.05 | 0.95 | 1.17 | 0.3392 |
20–24 | 1.09 | 1.06 | 1.12 | < .0001 | 1.09 | 1.06 | 1.11 | < .0001 | 0.88 | 0.81 | 0.95 | 0.0024 | 0.98 | 0.95 | 1.02 | 0.2914 |
25–29 | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
30–34 | 1.10 | 1.08 | 1.11 | < .0001 | 1.05 | 1.04 | 1.07 | < .0001 | 1.17 | 1.12 | 1.21 | < .0001 | 1.14 | 1.12 | 1.16 | < .0001 |
35–39 | 1.34 | 1.32 | 1.36 | < .0001 | 1.24 | 1.23 | 1.26 | < .0001 | 1.76 | 1.69 | 1.84 | < .0001 | 1.47 | 1.44 | 1.50 | < .0001 |
40–44 | 1.67 | 1.63 | 1.71 | < .0001 | 1.52 | 1.49 | 1.56 | < .0001 | 2.72 | 2.55 | 2.90 | < .0001 | 2.04 | 1.97 | 2.11 | < .0001 |
≥ 45 | 1.85 | 1.67 | 2.04 | < .0001 | 1.70 | 1.54 | 1.87 | < .0001 | 3.19 | 2.56 | 3.97 | < .0001 | 2.49 | 2.17 | 2.86 | < .0001 |
Household Income level | ||||||||||||||||
1Q (Low) | 1.17 | 1.15 | 1.19 | < .0001 | 1.14 | 1.12 | 1.16 | < .0001 | 1.30 | 1.24 | 1.36 | < .0001 | 1.13 | 1.10 | 1.15 | < .0001 |
2Q | 1.14 | 1.13 | 1.16 | < .0001 | 1.12 | 1.10 | 1.13 | < .0001 | 1.24 | 1.18 | 1.29 | < .0001 | 1.09 | 1.07 | 1.12 | < .0001 |
3Q | 1.07 | 1.06 | 1.09 | < .0001 | 1.06 | 1.05 | 1.08 | < .0001 | 1.11 | 1.07 | 1.16 | < .0001 | 1.04 | 1.02 | 1.06 | < .0001 |
4Q (High) | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Type of health insurance | ||||||||||||||||
Self-employed | 1.14 | 1.13 | 1.16 | < .0001 | 1.12 | 1.11 | 1.13 | < .0001 | 1.21 | 1.17 | 1.25 | < .0001 | 1.14 | 1.12 | 1.15 | < .0001 |
Employees | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Medical aid | 1.80 | 1.71 | 1.89 | < .0001 | 1.70 | 1.63 | 1.78 | < .0001 | 1.58 | 1.37 | 1.81 | < .0001 | 1.57 | 1.46 | 1.68 | < .0001 |
Residential areas | ||||||||||||||||
Seoul | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Metropolitans | 1.05 | 1.03 | 1.08 | < .0001 | 1.04 | 1.01 | 1.06 | 0.001 | 1.00 | 0.93 | 1.06 | 0.9168 | 1.05 | 1.02 | 1.08 | 0.0038 |
Small cities | 1.15 | 1.13 | 1.18 | < .0001 | 1.12 | 1.10 | 1.14 | < .0001 | 1.22 | 1.15 | 1.28 | < .0001 | 1.15 | 1.12 | 1.18 | < .0001 |
Rural | 1.21 | 1.18 | 1.24 | < .0001 | 1.17 | 1.14 | 1.20 | < .0001 | 1.49 | 1.39 | 1.60 | < .0001 | 1.39 | 1.34 | 1.44 | < .0001 |
Obstetric factors | ||||||||||||||||
Mode of delivery | ||||||||||||||||
Vaginal delivery | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Instrument delivery | 1.53 | 1.51 | 1.56 | < .0001 | 1.38 | 1.36 | 1.40 | < .0001 | 1.37 | 1.30 | 1.43 | < .0001 | 1.49 | 1.46 | 1.52 | < .0001 |
Cesarean section | 2.28 | 2.25 | 2.32 | < .0001 | 1.84 | 1.82 | 1.86 | < .0001 | 2.51 | 2.41 | 2.61 | < .0001 | 1.41 | 1.39 | 1.44 | < .0001 |
Preterm birth | ||||||||||||||||
No | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Yes | 1.39 | 1.36 | 1.42 | < .0001 | 1.36 | 1.34 | 1.39 | < .0001 | 1.61 | 1.53 | 1.70 | < .0001 | 1.53 | 1.49 | 1.58 | < .0001 |
Parity | ||||||||||||||||
0 | 1.25 | 1.24 | 1.27 | < .0001 | 1.27 | 1.26 | 1.28 | < .0001 | 1.15 | 1.12 | 1.19 | < .0001 | 1.39 | 1.37 | 1.41 | < .0001 |
1 + | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Multiple birth | ||||||||||||||||
No | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Yes | 1.64 | 1.60 | 1.67 | < .0001 | 1.59 | 1.56 | 1.62 | < .0001 | 1.37 | 1.29 | 1.46 | < .0001 | 1.37 | 1.32 | 1.42 | < .0001 |
Prenatal care* | ||||||||||||||||
Adequate | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Intermediate | 1.13 | 1.12 | 1.15 | < .0001 | 1.05 | 1.04 | 1.06 | < .0001 | 1.10 | 1.06 | 1.14 | < .0001 | 0.97 | 0.95 | 0.99 | 0.0032 |
Inadequate | 1.39 | 1.33 | 1.45 | < .0001 | 1.26 | 1.21 | 1.31 | < .0001 | 1.38 | 1.23 | 1.54 | < .0001 | 1.10 | 1.03 | 1.17 | 0.0066 |
Maternal comorbidities† | ||||||||||||||||
0 | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
≥ 1 | 1.51 | 1.50 | 1.53 | < .0001 | 1.42 | 1.41 | 1.43 | < .0001 | 2.32 | 2.25 | 2.39 | < .0001 | 1.33 | 1.31 | 1.35 | < .0001 |
Provision factors | ||||||||||||||||
Type of hospital | ||||||||||||||||
≥ 500 beds | 5.54 | 5.45 | 5.62 | < .0001 | 4.47 | 4.40 | 4.53 | < .0001 | 3.29 | 3.15 | 3.44 | < .0001 | 2.53 | 2.48 | 2.59 | < .0001 |
100–499 beds | 2.94 | 2.89 | 2.99 | < .0001 | 2.54 | 2.50 | 2.57 | < .0001 | 2.61 | 2.50 | 2.71 | < .0001 | 1.35 | 1.32 | 1.38 | < .0001 |
30–99 beds | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
< 30 beds | 1.04 | 1.03 | 1.06 | < .0001 | 1.04 | 1.03 | 1.06 | < .0001 | 0.69 | 0.66 | 0.72 | < .0001 | 0.81 | 0.80 | 0.83 | < .0001 |
Region of hospital | ||||||||||||||||
Seoul | 1.00 | 1.00 | 1.00 | 1.00 | ||||||||||||
Metropolitan | 1.35 | 1.32 | 1.38 | < .0001 | 1.32 | 1.30 | 1.35 | < .0001 | 1.60 | 1.51 | 1.69 | < .0001 | 1.52 | 1.47 | 1.57 | < .0001 |
Small cities | 1.23 | 1.21 | 1.25 | < .0001 | 1.22 | 1.20 | 1.24 | < .0001 | 1.02 | 0.97 | 1.07 | 0.4545 | 1.12 | 1.09 | 1.15 | < .0001 |
Rural | 1.17 | 1.10 | 1.24 | < 0.0001 | 1.19 | 1.13 | 1.26 | < .0001 | 0.47 | 0.38 | 0.60 | < .0001 | 0.92 | 0.84 | 1.01 | 0.0704 |