Table 1. Patient Characteristics and Measures of Association Between Individual and Hospital Characteristics and Neuraxial Labor Analgesia Use.
| Variable | No. (%) | Model 3 Multilevel Logistic Regression Adjusted OR (95% CI)a | ||
|---|---|---|---|---|
| Total Study Population | Women Using Neuraxial Labor Analgesia | Women Not Using Neuraxial Labor Analgesia | ||
| Patient Characteristics | ||||
| Maternal age, y | ||||
| <15 | 2010 (0.1) | 1541 (0.1) | 469 (0.1) | 1.71 (1.53-1.90) |
| 15-19 | 183 546 (7.0) | 140 945 (7.3) | 42 601 (6.0) | 1.17 (1.16-1.19) |
| 20-24 | 620 118 (23.6) | 463 646 (24.2) | 156 472 (22.2) | 1.10 (1.09-1.10) |
| 25-29 | 777 957 (29.6) | 569 055 (29.6) | 208 902 (29.6) | 1 [Reference] |
| 30-34 | 683 656 (26.0) | 493 142 (25.7) | 190 514 (27.0) | 0.96 (0.95-0.97) |
| 35-39 | 298 237 (11.4) | 210 061 (10.9) | 88 176 (12.5) | 0.93 (0.92-0.94) |
| 40-44 | 57 130 (2.2) | 39 654 (2.1) | 17 476 (2.5) | 0.90 (0.88-0.92) |
| 45-54 | 3296 (0.1) | 2324 (0.1) | 972 (0.1) | 0.90 (0.83-0.97) |
| Race/ethnicity | ||||
| Non-Hispanic white | 1 409 509 (53.7) | 1 081 556 (56.3) | 327 953 (46.5) | 1 [Reference] |
| Hispanic | 613 435 (23.4) | 401 407 (20.9) | 212 028 (30.1) | 0.75 (0.75-0.76) |
| Non-Hispanic Asian | 160 897 (6.1) | 117 559 (6.1) | 43 338 (6.1) | 0.99 (0.98-1.01) |
| Non-Hispanic black | 358 007 (13.6) | 261 844 (13.7) | 96 163 (13.6) | 0.86 (0.85-0.87) |
| Non-Hispanic other | 84 102 (3.2) | 58 002 (3.0) | 26 100 (3.7) | 0.81 (0.80-0.83) |
| Insurance type | ||||
| Private | 1 276 859 (48.6) | 980 724 (51.1) | 296 135 (42.0) | 1 [Reference] |
| Medicaid | 1 150 808 (43.8) | 809 383 (42.1) | 341 425 (48.4) | 0.81 (0.81-0.82) |
| Other | 112 405 (4.3) | 81 355 (4.2) | 31 050 (4.4) | 0.94 (0.92-0.95) |
| Self-pay | 85 878 (3.3) | 48 906 (2.6) | 36 972 (5.2) | 0.54 (0.53-0.55) |
| Highest level of education | ||||
| Grade ≤8 | 87 181 (3.3) | 44 232 (2.3) | 42 949 (6.1) | 0.57 (0.56-0.58) |
| Grade 9-12 with no diploma | 298 463 (11.4) | 202 227 (10.5) | 96 236 (13.6) | 0.87 (0.87-0.88) |
| High school graduate or GED completed | 668 690 (25.5) | 480 676 (25.0) | 188 014 (26.6) | 1 [Reference] |
| Associate degree | 213 058 (8.1) | 160 546 (8.4) | 52 512 (7.4) | 1.11 (1.10-1.13) |
| Some college credit but not a degree | 563 712 (21.5) | 426 204 (22.2) | 137 508 (19.5) | 1.14 (1.13-1.15) |
| Bachelor’s degree | 506 740 (19.3) | 386 178 (20.1) | 120 562 (17.1) | 1.14 (1.13-1.15) |
| Master’s degree | 224 024 (8.5) | 171 049 (8.9) | 52 975 (7.6) | 1.15 (1.13-1.16) |
| Doctorate or professional degree | 64 082 (2.4) | 49 256 (2.6) | 14 826 (2.1) | 1.21 (1.19-1.24) |
| Marital status | ||||
| Married | 1 532 444 (58.4) | 1 123 508 (58.5) | 408 936 (58.0) | 1 [Reference] |
| Unmarried | 1 093 506 (41.6) | 796 860 (41.5) | 296 646 (42.0) | 1.12 (1.11-1.13) |
| Body mass index at deliveryb | ||||
| Normal or underweight | 322 187 (12.3) | 223 910 (11.6) | 98 277 (13.9) | 1 [Reference] |
| Overweight | 943 032 (35.9) | 678 751 (35.3) | 264 281 (37.5) | 1.10 (1.09-1.11) |
| Obesity class I | 751 399 (28.6) | 552 265 (28.8) | 199 134 (28.2) | 1.19 (1.17-1.20) |
| Obesity class II | 370 724 (14.1) | 279 889 (14.6) | 90 835 (12.9) | 1.26 (1.25-1.28) |
| Obesity class III | 238 608 (9.1) | 185 553 (9.7) | 53 055 (7.5) | 1.33 (1.31-1.34) |
| Prepregnancy diabetes | 15 431 (0.6) | 12 097 (0.6) | 3334 (0.5) | 1.13 (1.08-1.18) |
| Prepregnancy hypertension | 35 540 (1.4) | 28 575 (1.5) | 6965 (1.0) | 1.14 (1.10-1.17) |
| No prior live birth | 1 142 006 (43.5) | 920 899 (48.0) | 221 107 (31.3) | 1.76 (1.75-1.77) |
| Previous cesarean delivery | 86 051 (3.3) | 66 047 (3.4) | 20 004 (2.8) | 1.87 (1.84-1.90) |
| Trimester when prenatal care was initiated | ||||
| First | 2 022 474 (77.0) | 1 502 462 (78.2) | 520 012 (73.7) | 1 [Reference] |
| Second | 449 955 (17.1) | 315 881 (16.5) | 134 074 (19.0) | 0.87 (0.87-0.88) |
| Third | 117 100 (4.5) | 81 490 (4.2) | 35 610 (5.0) | 0.87 (0.86-0.89) |
| No prenatal care | 36 421 (1.4) | 20 535 (1.1) | 15 886 (2.3) | 0.61 (0.59-0.62) |
| Gestational diabetes | 136 329 (5.2) | 102 916 (5.4) | 33 413 (4.7) | 1.04 (1.02-1.05) |
| Gestational hypertension or preeclampsia | 138 358 (5.3) | 114 564 (6.0) | 23 794 (3.4) | 1.19 (1.17-1.20) |
| Eclampsia | 4790 (0.2) | 3941 (0.2) | 849 (0.1) | 1.15 (1.06-1.24) |
| Gestational age at delivery, wk | ||||
| 37-42 | 2 459 720 (93.7) | 1 807 692 (94.1) | 652 028 (92.4) | 1 [Reference] |
| 24-36 | 162 016 (6.1) | 111 332 (5.8) | 50 684 (7.2) | 0.82 (0.81-0.83) |
| <24 | 4214 (0.2) | 1344 (0.1) | 2870 (0.4) | 0.17 (0.16-0.18) |
| Labor augmentation | 710 290 (27.0) | 586 970 (30.6) | 123 320 (17.5) | 2.31 (2.30-2.33) |
| Labor induction | 819 874 (31.2) | 685 271 (35.7) | 134 603 (19.1) | 2.31 (2.29-2.33) |
| Birth attendant | ||||
| Physician | 2 320 775 (88.4) | 1 739 608 (90.6) | 581 167 (82.4) | 1 [Reference] |
| Midwife | 289 862 (11.0) | 171 635 (8.9) | 118 227 (16.7) | 0.54 (0.54-0.55) |
| Other | 15 313 (0.6) | 9125 (0.5) | 6188 (0.9) | 0.61 (0.59-0.63) |
| Fetal presentation | ||||
| Cephalic | 2 581 813 (98.3) | 1 887 973 (98.3) | 693 840 (98.3) | 1 [Reference] |
| Breech | 14 907 (0.6) | 10 768 (0.6) | 4139 (0.6) | 1.19 (1.15-1.24) |
| Other | 29 230 (1.1) | 21 627 (1.1) | 7603 (1.1) | 1.07 (1.04-1.10) |
| Anesthesia Workforce Measures | ||||
| No. of anesthesiologists per 1000 birthsc | ||||
| 6.12-12.02 | 250 948 (9.6) | 173 428 (9.0) | 77 520 (11.0) | 1 [Reference] |
| 12.09-13.91 | 640 216 (24.4) | 482 377 (25.1) | 157 839 (22.4) | 1.50 (1.06-2.14) |
| 14.14-15.85 | 300 363 (11.4) | 239 475 (12.5) | 60 888 (8.6) | 1.59 (1.12-2.25) |
| 15.87-18.62 | 847 667 (32.3) | 585 548 (30.5) | 262 119 (37.1) | 1.20 (0.83-1.73) |
| 19.64-35.23 | 586 756 (22.3) | 439 540 (22.9) | 147 216 (20.9) | 1.05 (0.74-1.48) |
| No. of CRNAs per 1000 birthsc | ||||
| 4.58-8.49 | 727 396 (27.7) | 513 135 (26.7) | 214 261 (30.4) | 1 [Reference] |
| 8.53-12.41 | 371 557 (14.1) | 263 353 (13.7) | 108 204 (15.3) | 0.80 (0.56-1.14) |
| 12.62-21.19 | 684 418 (26.1) | 519 062 (27.0) | 165 356 (23.4) | 1.06 (0.74-1.51) |
| 23.32-29.87 | 488 127 (18.6) | 354 759 (18.5) | 133 368 (18.9) | 0.87 (0.61-1.25) |
| 30.19-38.31 | 354 452 (13.5) | 270 059 (14.1) | 84 393 (12.0) | 0.96 (0.66-1.36) |
Abbreviations: CRNAs, certified registered nurse anesthetists; GED, general equivalency diploma; OR, odds ratio.
a
Adjusted for maternal age, race/ethnicity, insurance type, highest level of education, marital status, body mass index at delivery, prepregnancy diabetes, prepregnancy hypertension, prior live birth, previous cesarean delivery, trimester when prenatal care was initiated, gestational diabetes, gestational hypertension or preeclampsia, eclampsia, gestational age at delivery, labor augmentation, labor induction, birth attendant, number of anesthesiologists per 1000 births, and number of CRNAs per 1000 births.
b
Body mass index (calculated as weight in kilograms divided by height in meters squared) categories are as follows: normal or underweight (<24.9), overweight (25-29.9), obesity class I (30-34.9), obesity class II (35-39.9), and obesity class III (≥40).
c
Ranges are quintiles.