Table 2.
Log linear regression models for postpartum hemorrhage, hemorrhage associated with blood transfusion and maternal morbidity associated with postpartum hemrorhage and/or blood transfusion.
| Postpartum hemorrhage | Hemorrhage with transfusion | Severe maternal morbidity | ||||
|---|---|---|---|---|---|---|
| Annualized delivery | ||||||
| <1000 | 1.14 | (1.04–1.25) | 1.10 | (0.99–1.23) | 1.02 | (0.91–1.15) |
| 1000–2000 | 1.04 | (0.97–1.13) | 1.04 | (0.94–1.14) | 0.99 | (0.90–1.09) |
| >2000 | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Mode of delivery | ||||||
| Primary cesarean | 0.59 | (0.56–0.62 | 2.78 | (2.72–2.85) | 3.35 | (3.15–3.55) |
| Repeat cesarean | 0.47 | (0.44–0.49) | 2.45 | (2.39–2.52) | 2.22 | (2.07–2.38) |
| Operative vaginal | 1.26 | (1.23–1.30) | 1.95 | (1.90–2.01) | 1.88 | (1.71–2.07) |
| Non-operative vaginal | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Labor induction | 1.24 | (1.22–1.26) | 1.02 | (1.00–1.04) | 0.98 | (0.92–1.05) |
| Multiple gestation | 2.32 | (2.25–2.39) | 2.37 | (2.29–2.45) | 1.80 | (1.64–1.98) |
| Stillbirth | 1.66 | (1.59–1.73) | 3.25 | (3.13–3.39) | 7.97 | (7.31–8.67) |
| Placental abruption | 1.67 | (1.61–1.74) | 4.18 | (4.05–4.30) | 4.88 | (4.51–5.26) |
| Fibroids | 1.46 | (1.39–1.53) | 1.39 | (1.33–1.47) | 1.13 | (0.98–1.30) |
| Antepartum | 1.51 | (1.40–1.64) | 4.10 | (3.88–4.33) | 6.68 | (5.91–7.55) |
| Polyhydramnios | 1.15 | (1.10–1.21) | 1.19 | (1.11–1.26) | 1.21 | (0.98–1.49) |
| Preeclampsia/Eclampsia | 2.23 | (2.17–2.29) | 2.80 | (2.72–2.88) | 5.48 | (5.13–5.84) |
| Chorioamnionitis | 2.17 | (2.09–2.25) | 1.77 | (1.67–1.87) | 2.20 | (1.98–2.44) |
| Placenta previa | 2.88 | (2.74–3.02) | 5.12 | (4.89–5.36) | 3.15 | (2.76–3.59) |
| Suspected macrosomia | 1.57 | (1.53–1.61) | 1.05 | (1.01–1.10) | 0.72 | (0.62–0.85) |
| Asthma | 1.02 | (0.99–1.05) | 1.10 | (1.06–1.15) | 1.28 | (1.15–1.42) |
| Chronic hypertension | 1.04 | (1.01–1.08) | 1.01 | (0.97–1.05) | 1.32 | (1.21–1.44) |
| Preexisting diabetes | 0.86 | (0.82–0.90) | 0.96 | (0.90–1.02) | 1.01 | (0.86–1.18) |
| Age (years) | ||||||
| 16–17 | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| 18–19 | 0.98 | (0.95–1.00) | 0.96 | (0.92–1.00) | 1.08 | (0.92–1.28) |
| 20–24 | 0.95 | (0.93–0.97) | 0.87 | (0.83–0.90) | 1.19 | (1.03–1.38) |
| 25–29 | 0.93 | (0.91–0.95) | 0.78 | (0.75–0.81) | 1.38 | (1.19–1.61) |
| 30–34 | 0.92 | (0.90–0.94) | 0.80 | (0.76–0.83) | 1.66 | (1.42–1.93) |
| ≥35 | 0.95 | (0.92–0.97) | 0.90 | (0.86–0.94) | 2.09 | (1.79–2.43) |
| Discharge year | ||||||
| 1998 | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| 1999 | 0.98 | (0.93–1.03) | 1.00 | (0.91–1.09) | 0.87 | (0.75–1.02) |
| 2000 | 0.99 | (0.94–1.05) | 1.11 | (1.01–1.22) | 0.81 | (0.69–0.96) |
| 2001 | 1.01 | (0.96–1.07) | 1.17 | (1.06–1.29) | 0.92 | (0.79–1.08) |
| 2002 | 1.03 | (0.98–1.09) | 1.30 | (1.18–1.44) | 0.91 | (0.78–1.07) |
| 2003 | 1.08 | (1.02–1.14) | 1.45 | (1.31–1.60) | 0.90 | (0.76–1.06) |
| 2004 | 1.09 | (1.03–1.15) | 1.51 | (1.37–1.66) | 0.98 | (0.83–1.15) |
| 2005 | 1.08 | (1.02–1.14) | 1.68 | (1.51–1.88) | 1.02 | (0.87–1.19) |
| 2006 | 1.09 | (1.03–1.15) | 1.84 | (1.68–2.02) | 1.10 | (0.94–1.28) |
| 2007 | 0.95 | (0.89–1.00) | 1.99 | (1.81–2.19( | 1.29 | (1.11–1.49) |
| 2008 | 0.96 | (0.90–1.03) | 2.10 | (1.91–2.31) | 1.53 | (1.32–1.77) |
| 2009 | 1.01 | (0.95–1.07) | 2.34 | (2.12–2.58) | 1.81 | (1.57–2.08) |
| 2010 | 1.04 | (0.98–1.11) | 2.51 | (2.28–2.76) | 1.62 | (1.39–1.88) |
| 2011 | 1.06 | (0.99–1.13) | 2.82 | (2.54–3.12) | 2.04 | (1.76–2.35) |
| Household income | ||||||
| Lowest quartile | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Second quartile | 0.99 | (0.98–1.01) | 0.96 | (0.94–0.98) | 0.99 | (0.93–1.05) |
| Third quartile | 0.99 | (0.98–1.01) | 0.90 | (0.87–0.93) | 0.95 | (0.88–1.02) |
| Highest quartile | 0.97 | (0.95–0.99) | 0.87 | (0.84–0.90) | 0.94 | (0.86–1.02) |
| Unknown | 1.05 | (0.99–1.11) | 1.03 | (0.94–1.12) | 1.00 | (0.83–1.21) |
| Insurance status | ||||||
| Medicare | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Medicaid | 1.04 | (0.98–1.11) | 0.73 | (0.67–0.79) | 0.83 | (0.65–1.07) |
| Private | 1.00 | (0.95–1.07) | 0.58 | (0.54–0.63) | 0.68 | (0.53–0.86) |
| Self pay | 1.04 | (0.97–1.11) | 0.81 | (0.74–0.89) | 0.79 | (0.60–1.04) |
| Other | 1.05 | (0.98–1.12) | 0.67 | (0.61–0.74) | 0.66 | (0.50–0.86) |
| Unknown | 1.01 | (0.90–1.13) | 0.71 | (0.60–0.84) | 0.75 | (0.41–1.36) |
| Race | ||||||
| White | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Black | 1.06 | (1.03–1.09) | 1.48 | (1.44–1.53) | 1.55 | (1.43–1.68) |
| Hispanic | 1.25 | (1.22–1.28) | 1.33 | (1.29–1.37) | 1.19 | (1.09–1.29) |
| Other | 1.23 | (1.20–1.27) | 1.31 | (1.27–1.36) | 1.58 | (1.46–1.71) |
| Unknown | 1.01 | (0.96–1.06) | 1.07 | (1.02–1.14) | 0.95 | (0.87–1.04) |
| Hospital bed size | ||||||
| Small | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Medium | 0.99 | (0.92–1.06) | 0.99 | (0.89–1.09) | 1.04 | (0.92–1.17) |
| Large | 0.91 | (0.85–0.97) | 0.86 | (0.87–1.06) | 1.13 | (1.01–1.27) |
| Unknown | 0.80 | (0.61–1.06) | 0.56 | (0.26–1.23) | 0.82 | (0.40–1.70) |
| Hospital Location | ||||||
| Rural | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Urban | 1.33 | (1.24–1.42) | 1.14 | (1.05–1.25) | 0.92 | (0.82–1.04) |
| Hospital Region | ||||||
| Northeast | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Midwest | 1.15 | (1.06–1.25) | 0.89 | (0.79–1.01) | 1.01 | (0.90–1.14) |
| South | 0.83 | (0.76–0.91) | 0.99 | (0.90–1.10) | 1.00 | (0.90–1.12) |
| West | 1.21 | (1.11–1.32) | 0.88 | (0.78–0.99) | 1.27 | (1.13–1.43) |
| Hospital Teaching | ||||||
| Non-teaching | 1.00 | (Reference) | 1.00 | (Reference) | 1.00 | (Reference) |
| Teaching | 0.95 | (0.88–1.02) | 0.84 | (0.77–0.92) | 0.78 | (0.71–0.85) |
All data are presented as adjusted risk ratios with 95% confidence intervals. Three individual models were created for (i) all postpartum hemorrhage, (ii) hemorrhage associated with blood transfusion and (iii) maternal morbidity associated with postpartum hemrorhage and/or blood transfusion