Table. Select Patient Characteristics After 1:4 Matching by State and Follow-upa.
| Characteristic | Any specific NDD, No. (%) | ASD, No. (%) | ADHD, No. (%) | |||
|---|---|---|---|---|---|---|
| Children with the outcome of interestb | Children without any NDDc | Children with the outcome of interestb | Children without any NDDc | Children with the outcome of interestb | Children without any NDDc | |
| Public insurance | ||||||
| Total | 71 604 | 286 416 | 10 093 | 40 372 | 33 259 | 133 036 |
| Follow-up, mean (SD), y | 5.3 (2.1) | 5.2 (2.1) | 6.8 (2.8) | 6.7 (2.9) | 7.3 (2.0) | 7.23 (2.0) |
| Maternal age at delivery, mean (SD), y | 24.8 (5.9) | 24.7 (6.0) | 25.8 (6.2) | 24.7 (6.0) | 23.9 (5.5) | 24.6 (6.0) |
| Sex | ||||||
| Male | 47 193 (65.9) | 137 567 (48.0) | 7703 (76.3) | 18 869 (46.7) | 23 171 (69.7) | 61 979 (46.6) |
| Female | 23 409 (32.7) | 146 556 (51.2) | 2207 (21.9) | 21 181 (52.5) | 9678 (29.1) | 70 045 (52.7) |
| Unknown | 1002 (1.4) | 2293 (0.8) | 183 (1.8) | 322 (0.8) | 410 (1.2) | 1012 (0.8) |
| Region | ||||||
| Northeast | 16 899 (23.6) | 67 596 (23.6) | 2586 (25.6) | 10 344 (25.6) | 6010 (18.1) | 24 040 (18.1) |
| Midwest | 19 721 (27.5) | 78 884 (27.5) | 2997 (29.7) | 11 988 (29.7) | 9852 (29.6) | 39 408 (29.6) |
| South | 18 597 (26.0) | 74 388 (26.0) | 2689 (26.6) | 10 756 (26.6) | 11 066 (33.3) | 44 264 (33.3) |
| West | 16 387 (22.9) | 65 548 (22.9) | 1821 (18.0) | 7284 (18.0) | 6331 (19.0) | 25 324 (19.0) |
| Year of birth | ||||||
| Before 2006 | 16 913 (23.6) | 84 379 (29.5) | 3928 (38.9) | 18 752 (46.5) | 14 640 (44.0) | 61 943 (46.6) |
| 2006-2009 | 39 143 (54.7) | 149 064 (52.0) | 4353 (43.1) | 15 923 (39.4) | 17 675 (53.1) | 67 192 (50.5) |
| After 2009 | 15 548 (21.7) | 52 973 (18.5) | 1812 (18.0) | 5697 (14.1) | 944 (2.8) | 3901 (2.9) |
| Race and ethnicityd | ||||||
| Asian or Pacific Islander | 2084 (2.9) | 13 488 (4.7) | 322 (3.2) | 1688 (4.2) | 398 (1.2) | 5254 (4.0) |
| Black or African American | 19 963 (27.9) | 97 518 (34.1) | 2660 (26.4) | 15 036 (37.2) | 10 263 (30.9) | 52 515 (39.5) |
| Hispanic or Latino | 9452 (13.2) | 40 893 (14.3) | 1106 (11.0) | 4748 (11.8) | 3295 (9.9) | 16 655 (12.5) |
| White | 33 071 (46.2) | 10 8112 (37.8) | 4848 (48.0) | 15 402 (38.2) | 17 283 (52.0) | 49 933 (37.5) |
| Other or unknowne | 7034 (9.8) | 26 405 (9.2) | 1157 (11.5) | 3498 (8.7) | 2020 (6.1) | 8679 (6.5) |
| Maternal conditions | ||||||
| Preexisting hypertension | 2286 (3.2) | 6519 (2.3) | 385 (3.8) | 933 (2.3) | 1012 (3.0) | 3077 (2.3) |
| Preeclampsia | 4595 (6.4) | 14 408 (5.0) | 653 (6.5) | 2008 (5.0) | 2037 (6.1) | 6601 (5.0) |
| Preexisting diabetes | 2642 (3.7) | 7238 (2.5) | 444 (4.4) | 988 (2.5) | 1078 (3.2) | 3121 (2.4) |
| Gestational diabetes | 136 (0.2) | 422 (0.2) | 20 (0.2) | 57 (0.1) | 53 (0.2) | 202 (0.2) |
| Obstetric conditions | ||||||
| Low birth weight | 5805 (8.1) | 12 016 (4.2) | 762 (7.6) | 1724 (4.3) | 2107 (6.3) | 5765 (4.3) |
| Small for gestational age | 2943 (4.1) | 8406 (2.9) | 364 (3.6) | 1134 (2.8) | 1104 (3.3) | 3626 (2.7) |
| Neonatal hypoxia or asphyxia | 756 (1.1) | 2191 (0.8) | 108 (1.1) | 358 (0.9) | 337 (1.0) | 1187 (0.9) |
| Preterm birth (>28 and <37 wk gestation) | 10 846 (15.2) | 27 244 (9.5) | 1521 (15.1) | 3788 (9.4) | 4306 (13.0) | 12 809 (9.6) |
| Very preterm birth (≤28 wk gestation) | 1296 (1.8) | 1444 (0.5) | 146 (1.5) | 210 (0.5) | 318 (1.0) | 670 (0.5) |
| No. of specific NDDs, mean (SD) | 1.3 (0.6) | NA | 2.3 (1.1) | NA | 1.7 (0.8) | NA |
| Private insurancef | ||||||
| Total | 32 426 | 129 704 | 3847 | 15 388 | 8260 | 33 040 |
| Follow-up, mean (SD), y | 5.7 (2.7) | 5.6 (2.7) | 5.9 (2.4) | 5.9 (2.5) | 8.5 (1.9) | 8.4 (1.9) |
| Maternal age at delivery, mean (SD), y | 32.7 (4.7) | 32.3 (4.6) | 33.1 (4.8) | 32.4 (4.6) | 32.1 (4.8) | 32.2 (4.5) |
| Sex | ||||||
| Male | 22 229 (68.6) | 64 094 (49.4) | 3002 (78.0) | 7534 (49.0) | 5942 (71.9) | 16 045 (48.6) |
| Female | 9395 (29.0) | 64 461 (49.7) | 726 (18.9) | 7695 (50.0) | 2168 (26.3) | 16 710 (50.6) |
| Unknown | 802 (2.5) | 1149 (0.9) | 119 (3.1) | 159 (1.0) | 150 (1.8) | 285 (0.9) |
| Region | ||||||
| Northeast | 6075 (18.7) | 24 300 (18.7) | 973 (25.3) | 3892 (25.3) | 934 (11.3) | 3736 (11.3) |
| Midwest | 8649 (26.7) | 34 596 (26.7) | 825 (21.5) | 3300 (21.5) | 2140 (25.9) | 8560 (25.9) |
| South | 12 901 (39.8) | 51 604 (39.8) | 1398 (36.3) | 5592 (36.3) | 4440 (53.8) | 17 760 (53.8) |
| West | 4582 (14.1) | 18 328 (14.1) | 620 (16.1) | 2480 (16.1) | 699 (8.5) | 2796 (8.5) |
| Year of birth | ||||||
| Before 2006 | 4491 (13.9) | 20 395 (15.7) | 525 (13.7) | 2408 (15.7) | 2692 (32.6) | 10 629 (32.2) |
| 2006-2009 | 13 670 (42.2) | 57 992 (44.7) | 1731 (45.0) | 7227 (47.0) | 5019 (60.8) | 20 101 (60.8) |
| After 2009 | 14 265 (44.0) | 51 317 (39.6) | 1591 (41.4) | 5753 (37.4) | 549 (6.7) | 2310 (7.0) |
| Maternal conditions | ||||||
| Preexisting hypertension | 943 (2.9) | 2797 (2.2) | 121 (3.2) | 332 (2.2) | 225 (2.7) | 703 (2.1) |
| Preeclampsia | 2807 (8.7) | 7458 (5.8) | 361 (9.4) | 886 (5.8) | 694 (8.4) | 1835 (5.6) |
| Preexisting diabetes | 978 (3.0) | 2910 (2.2) | 141 (3.7) | 340 (2.2) | 270 (3.3) | 713 (2.2) |
| Gestational diabetes | 40 (0.1) | 169 (0.1) | 4 (0.1) | 14 (0.1) | 5 (0.1) | 45 (0.1) |
| Obstetric conditions | ||||||
| Low birth weight | 2512 (7.8) | 3958 (3.1) | 287 (7.5) | 451 (2.9) | 457 (5.5) | 980 (3.0) |
| Small for gestational age | 1372 (4.2) | 3345 (2.6) | 149 (3.9) | 374 (2.4) | 222 (2.7) | 626 (1.9) |
| Neonatal hypoxia or asphyxia | 291 (0.9) | 895 (0.7) | 38 (1.0) | 102 (0.7) | 58 (0.7) | 238 (0.7) |
| Preterm birth (>28 and <37 wk gestation) | 4847 (15.0) | 10 316 (8.0) | 577 (15.0) | 1239 (8.1) | 1009 (12.2) | 2575 (7.8) |
| Very preterm birth (≤28 wk gestation) | 674 (2.1) | 632 (0.5) | 77 (2.0) | 67 (0.4) | 96 (1.2) | 188 (0.6) |
| No. of specific NDDs, mean (SD) | 1.2 (0.5) | NA | 2.0 (0.8) | NA | 1.5 (0.8) | NA |
Abbreviations: ADHD, attention-deficit/hyperactivity disorder or hyperkinetic syndrome of childhood; ASD, autism spectrum disorder or pervasive developmental disorder; LMP, last menstrual period; NA, not available; NDD, neurodevelopmental disorder.
The following assessment periods were used for the respective covariates: first date of LMP minus 90 days to LMP plus 90 days: preexisting hypertension; LMP minus 90 days to LMP plus 140 days: preexisting diabetes; LMP plus 140 days to delivery: gestational diabetes; LMP plus 140 days to delivery plus 30 days: preeclampsia; delivery to delivery plus 30 days: preterm or very preterm birth, low birth weight, and small for gestational age; and delivery hospitalization: neonatal hypoxia or asphyxia. Last menstrual period and gestational age at birth were estimated using a previously validated algorithm that is based on diagnostic codes for preterm birth recorded in either the maternal or infant claims within the first month after delivery or birth.17
Cohort includes all children with the specific NDD of interest.
Cohort consists of a sample of children without any NDD, which is defined using an extended definition that also includes other developmental, neurotic, and personality disorders (eTable 1 in the Supplement). Children with the specific NDD of interest and those without any NDD were 1:4 matched on state and duration of follow-up after birth (±60 days).
Race and ethnicity were determined on the basis of information submitted to the Centers for Medicare & Medicaid Services by individual states, which was based on information that had been collected and coded from Medicaid applications.
Race and ethnicity category “other or unknown” includes the following races and ethnicities: American Indian or Alaska Native, Native Hawaiian or Other Pacific Islander, Hispanic or Latino and 1 or more races, more than 1 race, and unknown. The category “Hispanic or Latino” includes Hispanic or Latino with no race information available, whereas “other or unknown” includes Hispanic or Latino with 1 or more races.
Information on race and ethnicity not available in the privately insured cohort (MarketScan).