TABLE 1.
Baseline Characteristics Stratified by Exposure to β Blockers, Before and After PS Matching
| Full Cohort | Matched Cohort | ||||
|---|---|---|---|---|---|
| β Blocker Exposed | β Blocker Unexposed | β Blocker Exposed | β Blocker Unexposed | Absolute Difference | |
| Total | 10 585 | 2 281 531 | 10 561 | 31 683 | |
| Age (y) | |||||
| ≤19 | 894 (8.5) | 440 708 (19.3) | 894 (8.5) | 2906 (9.2) | −0.7 |
| 20–24 | 2921 (27.6) | 938 225 (41.1) | 2920 (27.7) | 9088 (28.7) | −1 |
| 25–29 | 2787 (26.3) | 527 668 (23.1) | 2784 (26.4) | 8505 (26.8) | −0.5 |
| 30–34 | 2069 (19.6) | 240 599 (10.6) | 2060 (19.5) | 5948 (18.8) | 0.7 |
| 35–39 | 1400 (13.2) | 107 070 (4.7) | 1392 (13.2) | 3882 (12.3) | 0.9 |
| ≥40 | 514 (4.9) | 27261 (1.2) | 511 (4.8) | 1354 (4.3) | 0.6 |
| Race | |||||
| White | 6347 (60) | 1 121 952 (49.2) | 6328 (59.9) | 19 374 (61.2) | −1.2 |
| Black | 2658 (25.1) | 574 024 (25.2) | 2654 (25.1) | 8028 (25.3) | −0.2 |
| Hispanic | 746 (7.1) | 296 576 (13) | 746 (7.1) | 2099 (6.6) | 0.4 |
| Asian | 189 (1.8) | 75 534 (3.3) | 188 (1.8) | 445 (1.4) | 0.4 |
| Other | 395 (3.7) | 147 696 (6.5) | 395 (3.7) | 1059 (3.3) | 0.4 |
| Unknown | 250 (2.4) | 65 749 (2.9) | 250 (2.4) | 678 (2.1) | 0.2 |
| Medical/obstetrical conditions | |||||
| Preexisting hypertension | 6309 (59.6) | 76 218 (3.3) | 6285 (59.5) | 19 251 (60.8) | −1.3 |
| Gestational hypertension | 4022 (38) | 110 315 (4.8) | 4006 (37.9) | 12 670 (40) | −2.1 |
| Mild preeclampsia | 2626 (24.8) | 92 618 (4.1) | 2615 (24.8) | 8018 (25.3) | −0.5 |
| Severe preeclampsia | 2474 (23.4) | 42 122 (1.9) | 2464 (23.3) | 6828 (21.6) | 1.8 |
| Migraine | 387 (3.7) | 18 859 (0.8) | 383 (3.6) | 1251 (4) | −0.3 |
| Cardiac arrhythmia | 973 (9.2) | 16 524 (0.7) | 953 (9) | 2848 (9) | 0 |
| Ischemic heart disease | 48 (0.5) | 591 (0) | 45 (0.4) | 88 (0.3) | 0.2 |
| Anxiety | 308 (2.9) | 21 456 (0.9) | 304 (2.9) | 912 (2.9) | 0 |
| Congestive heart failure | 279 (2.6) | 3025 (0.1) | 268 (2.5) | 554 (1.8) | 0.8 |
| Multiple gestation | 259 (2.5) | 34 670 (1.5) | 258 (2.4) | 761 (2.4) | 0 |
| Preterm delivery | 3107 (29.4) | 263 861 (11.6) | 3089 (29.3) | 8573 (27.1) | 2.2 |
| Preexisting diabetes | 1466 (13.9) | 85 451 (3.8) | 1458 (13.8) | 4063 (12.8) | 1 |
| Gestational diabetes | 2175 (20.6) | 190 371 (8.3) | 2161 (20.5) | 6281 (19.8) | 0.6 |
Also included in the PS model: alcohol abuse, illicit drug use, tobacco use, chronic renal disease, essential tremor, number of distinct non–β blocker prescription drugs and physician visits during baseline period, calendar year, and maternal exposure to insulin or oral hypogylcemics in the final month of pregnancy.