Table 2.
Multivariable logistic regression for OASIS among all vaginal births (2016–2023).
| Unadjusted OR (95% CI) | Adjusted OR (95% CI) | |
|---|---|---|
| Mode of Delivery | ||
| SVD | Ref | Ref |
| VAVD | 6.06 (5.99–6.14) | 3.90 (3.85–3.94) |
| FAVD | 15.17 (14.91–15.43) | 9.50 (9.33–9.66) |
| Maternal Age Categories | ||
| Age 16–19 | 0.85 (0.83–0.87) | 0.64 (0.63–0.66) |
| Age 20–24 | 0.79 (0.78–0.80) | 0.75 (0.74–0.76) |
| Age 25–29 | Ref | Ref |
| Age 30–34 | 1.09 (1.08–1.10) | 1.10 (1.08–1.11) |
| Age 35–39 | 0.88 (0.87–0.89) | 1.04 (1.03–1.06) |
| Age 40–44 | 0.69 (0.66–0.71) | 0.90 (0.87–0.93) |
| Age ≥ 45 | 0.66 (0.58–0.76) | 0.79 (0.68–0.90) |
| BMI Categories | ||
| BMI <18.5 | 0.98 (0.96–1.01) | 1.00 (0.98–1.02) |
| BMI 18.5–24.9 | Ref | Ref |
| BMI 25.0–29.9 | 0.81 (0.80–0.82) | 0.92 (0.91–0.93) |
| BMI 30–34.9 | 0.62 (0.62–0.63) | 0.77 (0.76–0.78) |
| BMI 35–39.9 | 0.54 (0.53–0.55) | 0.67 (0.66–0.69) |
| BMI ≥ 40 | 0.47 (0.45–0.48) | 0.58 (0.57–0.60) |
| Unknown | 0.78 (0.76–0.81) | 1.01 (0.98–1.04) |
| Maternal Race/Ethnicity | ||
| Non-Hispanic White | Ref | Ref |
| Non-Hispanic Black | 0.50 (0.49–0.51) | 0.73 (0.71–0.74) |
| Non-Hispanic American Indian or Alaskan Native | 0.66 (0.62–0.70) | 1.02 (0.96–1.08) |
| Non-Hispanic Asian | 2.12 (2.10–2.15) | 1.73 (1.71–1.76) |
| Non-Hispanic Native Hawaiian or Pacific Islander | 0.76 (0.70–0.84) | 1.16 (1.06–1.27) |
| Non-Hispanic More than One Race | 0.73 (0.70–0.75) | 0.83 (0.81–0.86) |
| Hispanic | 0.60 (0.59–0.61) | 0.83 (0.82–0.84) |
| Unknown | 1.05 (1.00–1.09) | 1.08 (1.03–1.12) |
| Private Insurance * | 2.01 (2.00–2.03) | 1.27 (1.26–1.28) |
| Nulliparity | 5.05 (5.00–5.10) | 4.44 (4.39–4.49) |
| Labor Comorbidities | ||
| Pre-gestational Diabetes | 1.23 (1.17–1.29) | 1.34 (1.28–1.41) |
| Gestational Diabetes | 1.18 (1.16–1.20) | 1.16 (1.14–1.18) |
| Chronic Hypertension | 0.82 (0.79–0.85) | 0.97 (0.93–1.01) |
| Gestational Hypertension | 1.26 (1.24–1.28) | 1.10 (1.08–1.12) |
| Pre-eclampsia Spectrum | 1.13 (1.02–1.24) | 1.04 (0.94–1.14) |
| Induction of Labor | 1.24 (1.23–1.25) | 1.19 (1.18–1.20) |
| Augmentation of Labor | 1.53 (1.52–1.54) | 1.33 (1.32–1.34) |
| Birthweight >4000g | 2.12 (2.09–2.15) | 2.71 (2.67–2.74) |
| Year of Delivery | ||
| 2016 | Ref | Ref |
| 2017 | 1.26 (1.23–1.28) | 1.27 (1.25–1.29) |
| 2018 | 1.27 (1.25–1.29) | 1.28 (1.26–1.31) |
| 2019 | 1.26 (1.24–1.28) | 1.27 (1.25–1.29) |
| 2020 | 1.19 (1.17–1.16) | 1.19 (1.17–1.21) |
| 2021 | 1.14 (1.12–1.16) | 1.14 (1.12–1.16) |
| 2022 | 1.18 (1.16–1.20) | 1.19 (1.17–1.21) |
| 2023 | 1.20 (1.18–1.22) | 1.22 (1.19–1.24) |
*
Reference for private insurance includes any other payer status including Medicaid, self-pay, Indian health service, Tricare, other government, other pay, or unknown.