Table 5.
Adjusted relative risk of dual burden of severe maternal morbidity and preterm birth by sociodemographic, pregnancy, and obstetric factors, stratified by insurance Payor, California 2007–2012
| Characteristic | Medical | Private | Uninsured | Othera |
|---|---|---|---|---|
| n = 1,462,463 | n = 1,431,956 | n = 64,507 | n = 100,149 | |
| aRR (95% CI) | aRR (95% CI) | aRR (95% CI) | aRR (95% CI) | |
| Sociodemographic characteristics | ||||
| Maternal age | ||||
| < 18 | 1.12 (0.95–1.33) | 1.63 (1.16–2.29) | 1.50 (0.78–2.87) | 1.75 (1.01–3.01) |
| 18–25 | Reference | Reference | Reference | Reference |
| 26–35b | 1.11 (1.03–1.19) | 0.99 (0.91–1.08) | 0.62 (0.43–0.89) | 1.23 (0.90–1.69) |
| > 35c,e,g | 1.45 (1.31–1.60) | 1.30 (1.17–1.46) | 0.86 (0.60–1.25) | 1.62 (1.10–2.37) |
| Race/ethnicity | ||||
| White non-Hispanic | Reference | Reference | Reference | Reference |
| Hispanic b,c,e,g | 1.03 (0.93–1.14) | 1.24 (1.13–1.37) | 0.72 (0.52–1.01) | 1.24 (0.92–1.68) |
| Black, non-Hispanic | 1.91 (1.66–2.18) | 1.93 (1.66–2.25) | 1.55 (1.00–2.44) | 2.16 (1.55–3.01) |
| Asian, non-Hispanicc,d,e | 1.09 (0.89–1.33) | 1.26 (1.11–1.43) | 0.46 (0.20–1.05) | 0.83 (0.53–1.33) |
| Other, non-Hispanicc | 1.28 (1.12–1.46) | 1.47 (1.29–1.67) | 1.08 (0.68–1.71) | 1.11 (0.67–1.84) |
| Education | ||||
| < 12 yearsb,d | 0.95 (0.87–1.03) | 1.22 (1.06–1.41) | 1.12 (0.85–1.49) | 1.05 (0.75–1.46) |
| 12 years | Reference | Reference | Reference | Reference |
| > 12 years | 0.96 (0.88–1.05) | 0.85 (0.77 -0.93) | 0.69 (0.45–1.04) | 0.80 (0.60–1.05) |
| Urban/rural statush | ||||
| 1 (most urban) | Reference | Reference | Reference | Reference |
| 2c,d | 1.10 (0.89–1.35) | 1.13 (1.00–1.29) | 1.91 (1.16–3.15) | 1.15 (0.64–2.04) |
| 3c,d | 1.01 (0.84–1.20) | 1.01 (0.84–1.21) | 1.86 (1.11–3.10) | 1.05 (0.72–1.54) |
| 4 | 0.89 (0.71–1.11) | 0.92 (0.68–1.24) | 0.89 (0.42–1.92) | 0.79 (0.32–1.90) |
| 5 | 1.07 (0.66–1.74) | 0.79 (0.46–1.37) | 1.91 (0.59–6.14) | h |
| 6 (most rural) | 0.72 (0.45–1.16) | 0.82 (0.38–1.76) | h | h |
| Prenatal factors | ||||
| Maternal pre-pregnancy BMI | ||||
| < 18.5 | 1.33 (1.17–1.52) | 1.44 (1.23–1.69) | 1.22 (0.77–1.93) | 1.49 (0.96–2.31) |
| 18.5–24.9 | Reference | Reference | Reference | Reference |
| 25.0–29.9 | 0.81 (0.75–0.87) | 0.87 (0.79–0.96) | 0.96 (0.69–1.34) | 0.78 (0.60–1.02) |
| ≥ 30 | 0.68 (0.63–0.74) | 0.77 (0.69–0.87) | 0.81 (0.54–1.20) | 0.72 (0.53–0.98) |
| Prenatal carei | ||||
| Inadequatec,e | 1.12 (1.02–1.21) | 1.05 (0.93–1.19) | 1.58 (1.14–2.21) | 1.37 (0.99–1.89) |
| Intermediate | 0.74 (0.60–0.91) | 0.66 (0.55–0.78) | 0.65 (0.29–1.48) | 0.95 (0.59–1.55) |
| Adequate/adequate plus | Reference | Reference | Reference | Reference |
| Smoked during pregnancyc,e,g | 1.58 (1.40–1.80) | 1.20 (0.91–1.57) | 2.93 (1.96–4.37) | 1.51 (1.03–2.21) |
| Pregnancy factors | ||||
| Parity and mode of birth | ||||
| Primiparous vaginal | Reference | Reference | Reference | Reference |
| Multiparous vaginalb,c,e | 0.90 (0.80–1.01) | 0.76 (0.68–0.86) | 1.70 (1.00–2.88)g | 1.03 (0.64–1.64) |
| Primiparous primary cesareanf | 3.07 (2.72–3.47) | 3.41 (3.01–3.87) | 4.29 (2.31–7.97) | 5.38 (3.53–8.21) |
| Multiparous primary cesareanc,e,f | 8.21 (7.05–9.57) | 7.03 (5.95–8.31) | 19.35 (10.33–36.33) | 12.77 (8.24–19.78) |
| Repeat cesareanc,e | 3.92 (3.47–4.42) | 3.33 (2.91–3.80) | 6.89 (4.22–11.26) | 4.43 (2.88–6.80) |
| Pregnancy type | ||||
| Singleton | Reference | Reference | Reference | Reference |
| Multiple gestationc,e,g | 6.00 (5.28–6.82) | 6.93 (6.24–7.70) | 3.80 (2.54–5.67) | 7.94 (5.99–10.52) |
| Obstetric co-morbidities | ||||
| Hypertension | ||||
| No HTN | Reference | Reference | Reference | Reference |
| Preexisting HTN without preeclampsiab,e | 3.84 (3.28–4.51) | 2.65 (2.21–3.19) | 7.27 (3.64–14.51) | 3.26 (1.92–5.53) |
| Preexisting HTN with preeclampsiab | 12.98 (11.21–15.03) | 9.12 (7.62–10.92) | 15.87 (9.14–27.57) | 9.13 (5.76–14.46) |
| Gestational HTN without preeclampsia | 1.86 (1.56–2.22) | 1.45 (1.16–1.82) | 1.89 (0.84–4.24) | 1.57 (0.79–3.12) |
| Gestational HTN with preeclampsia | 7.60 (6.79–8.50) | 6.93 (6.28–7.65) | 8.13 (5.35–12.35) | 8.02 (5.64–11.42) |
| Diabetes | ||||
| No diabetes | Reference | Reference | Reference | Reference |
| Gestational diabetesd | 2.54 (2.16–2.99) | 2.62 (2.21–3.11) | 3.43 (1.76–6.68) | 1.30 (0.50–3.38) |
| Preexisting diabetesd | 1.14 (1.05–1.24) | 1.16 (1.06–1.27) | 1.20 (0.74–1.97) | 1.00 (0.72–1.39) |
BMI body mass index, HTN hypertension, aRR adjusted relative risks; Relative risks adjusted by all other variables in the table
aOther insurance includes: Indian Health Service, CHAMPUS or TRICARE, other local, state, or federal insurance, or charity
bpairwise comparison Medi-Cal vs. private p < 0.05
cpairwise comparison Medi-Cal vs. uninsured p < 0.05
dpairwise comparison Medi-Cal vs. other p < 0.05
epairwise comparison private vs. uninsured p < 0.05
fpairwise comparison private vs. other p < 0.05
gpairwise comparison uninsured vs. other p < 0.05
hFederal Information Processing Standard categories
iKotelchuck Adequacy of Prenatal Care Utilization Index (Harrison & Goldenberg, 2016)