TABLE 2.
Cognitive Assessments at 18–22 mo and 6–7 y
| All Participants | Hypothermia | Normothermia | Hypothermia vs Normothermia | |
|---|---|---|---|---|
| P | ||||
| 18- to 22-mo neurodevelopmental assessment | ||||
| MDI | N = 110 | N = 63 | N = 47 | |
| Mean (SD) | 79.7 (20.1) | 81.9 (19.2) | 76.8 (21.0) | .19 |
| Median (Q1, Q3) | 83 (68, 94) | 85 (72, 93) | 79 (50, 94) | |
| (Minimum, maximum) | (49, 128) | (49, 128) | (49, 113) | |
| >84, n (%) | 53 (48) | 33 (52) | 20 (43) | .31 |
| 70–84, n (%) | 27 (25) | 17 (27) | 10 (21) | |
| 55–69, n (%) | 6 (5) | 2 (3) | 4 (9) | |
| <55, n (%) | 24 (22) | 11 (17) | 13 (28) | |
| 6- to 7-y neurodevelopmental assessment | ||||
| Full Scale IQa | N = 110 | N = 63 | N = 47 | |
| Mean (SD) | 78.5 (23.8) | 80.9 (23.3) | 75.3 (24.4) | .23 |
| Median (Q1, Q3) | 83 (65, 96) | 83 (69, 98) | 81 (40, 91) | |
| (Minimum, maximum) | (39, 121) | (39, 121) | (39, 116) | |
| >84, n (%) | 52 (47) | 30 (48) | 22 (47) | .75 |
| 70–84, n (%) | 27 (25) | 17 (27) | 10 (21) | |
| 55–69, n (%) | 8 (7) | 5 (8) | 3 (6) | |
| <55, n (%) | 23 (21) | 11 (17) | 12 (26) | |
| Verbal IQ | N = 91 | N = 55 | N = 36 | |
| Mean (SD) | 86.1 (17.1) | 85.9 (19.1) | 86.4 (13.7) | .88 |
| Median (Q1, Q3) | 85 (75, 101) | 85 (72, 102) | 85.5 (77, 96) | |
| (Minimum, maximum) | (46, 118) | (46, 118) | (46, 112) | |
| >84, n (%) | 51 (56) | 30 (55) | 21 (58) | .10 |
| 70–84, n (%) | 25 (27) | 12 (22) | 13 (36) | |
| 55–69, n (%) | 10 (11) | 9 (16) | 1 (3) | |
| <55, n (%) | 5 (5) | 4 (7) | 1 (3) | |
| Performance IQ | N = 91 | N = 55 | N = 36 | |
| Mean (SD) | 91.0 (16.8) | 91.3 (17.3) | 90.5 (16.3) | .82 |
| Median (Q1, Q3) | 90 (82, 101) | 93 (81, 104) | 89 (84, 100.5) | |
| (Minimum, maximum) | (45, 127) | (45, 127) | (45, 127) | |
| >84, n (%) | 59 (65) | 35 (64) | 24 (67) | .76 |
| 70–84, n (%) | 24 (26) | 16 (29) | 8 (22) | |
| 55–69, n (%) | 5 (5) | 2 (4) | 3 (8) | |
| <55, n (%) | 3 (3) | 2 (4) | 1 (3) | |
| Processing speed quotient | N = 87 | N = 53 | N = 34 | |
| Mean (SD) | 92.9 (17.0) | 93.2 (17.2) | 92.4 (17.0) | .84 |
| Median (Q1, Q3) | 94 (83, 103) | 94 (83, 104) | 91 (80, 102) | |
| (Minimum, maximum) | (45, 143) | (45, 123) | (49, 143) | |
| >84, n (%) | 62 (71) | 39 (74) | 23 (68) | .61 |
| 70–84, n (%) | 21 (24) | 11 (21) | 10 (29) | |
| 55–69, n (%) | 0 (0) | 0 (0) | 0 (0) | |
| <55, n (%) | 4 (5) | 3 (6) | 1 (3) | |
| Attention or executive function core domain score | N = 77 | N = 46 | N = 31 | |
| Mean (SD) | 93.7 (16.6) | 94.5 (15.1) | 92.6 (18.7) | .63 |
| Median (Q1, Q3) | 95 (85, 104) | 95 (85, 104) | 95 (82, 110) | |
| (Minimum, maximum) | (50, 121) | (52, 121) | (50, 119) | |
| >84, n (%) | 60 (78) | 38 (83) | 22 (71) | .19 |
| 70–84, n (%) | 11 (14) | 6 (13) | 5 (16) | |
| 55–69, n (%) | 3 (4) | 0 (0) | 3 (10) | |
| <55, n (%) | 3 (4) | 2 (4) | 1 (3) | |
| No score, n (%) | 33/110 (30) | 17/63 (27) | 16/47 (34) | |
| Untestable | 29 (26) | 14 (22) | 15 (32) | |
| Due to neurologic or cognitive impairment | 24 (22) | 11 (17) | 13 (28) | |
| Other reasons | 5 (5) | 3 (5) | 2 (4) | |
| Missing, no reason | 4 (4) | 3 (5) | 1 (2) | |
| Visuospatial core domain score | N = 84 | N = 50 | N = 34 | |
| Mean (SD) | 97.7 (16.2) | 98.5 (15.6) | 96.5 (17.2) | .58 |
| Median (Q1, Q3) | 97 (85, 109) | 97 (88, 109) | 97 (85, 112) | |
| (Minimum, maximum) | (57, 132) | (57, 132) | (57, 127) | |
| >84, n (%) | 70 (83) | 42 (84) | 28 (82) | .89 |
| 70–84, n (%) | 11 (13) | 6 (12) | 5 (15) | |
| 55–69, n (%) | 3 (4) | 2 (4) | 1 (3) | |
| <55, n (%) | 0 (0) | 0 (0) | 0 (0) | |
| No score, n (%) | 26/110 (24) | 13/63 (21) | 13/47 (28) | |
| Untestable | 23 (21) | 11 (17) | 12 (26) | |
| Due to neurologic impairment | 20 (18) | 8 (13) | 12 (26) | |
| Due to cognitive impairment | 3 (3) | 3 (5) | 0 (0) | |
| Due to other reasons | 3 (3) | 2 (3) | 1 (2) | |
| Missing, no reason |
At 18 mo, the BSID-II MDI was used to assess neurodevelopmental outcomes. At 6–7 y, the WPPSI-III (n = 93) or Wechsler Intelligence Scale for Children, Fourth Edition Full Scale IQ (n = 17) and the Neuropsychological Assessment (NEPSY) attention or executive function (n = 77) and visuospatial processing subscales (n = 84) were used to assess cognitive outcomes. Test score comparisons were conducted with Fisher exact tests for categorical data and 2-sided t tests for continuous data. Q1, quartile 1; Q3, quartile 3.
Children deemed so severely impaired as to preclude psychometric evaluation (n = 19) were assigned a Full Scale IQ of 39. No scores were imputed for verbal IQ, performance IQ, or processing speed quotient.