TABLE 2

Primary and Secondary Outcome

OutcomesIodide, N = 631Placebo, N = 628Mean Difference, Iodide – Placebo95% CI (P)
Primary outcomes, intention-to-treat population, mean ± SDa
 Bayley-III cognitive score88.9 ± 19.289.2 ± 19.5−0.34−2.57 to 1.89 (.77)
 Bayley-III motor composite score88.2 ± 21.088.0 ± 21.60.21−2.23 to 2.65 (.87)
 Bayley-III language composite score85.1 ± 21.785.2 ± 21.8−0.05−2.48 to 2.39 (.97)
Secondary outcomes Bayley-III subtests, intention-to-treat population, mean ± SDb99% CI
 Receptive communication7.51 ± 3.807.46 ± 3.770.05−0.51 to 0.61
 Expressive communication7.31 ± 4.067.34 ± 4.06−0.02−0.62 to 0.57
 Fine motor8.86 ± 3.998.72 ± 4.130.15−0.47 to 0.76
 Gross motor7.07 ± 3.617.16 ± 3.68−0.09−0.63 to 0.45
Low score in any main Bayley domain (ie, cognitive, motor, language), intention-to-treat population, n (%)aOR (99% CI)
 ≥85305.7 (48)319.6 (51)1.10 (0.82 to 1.49)
 <85 (or death)325.3 (52)308.4 (49)
Postnatal infant conditions, survivors only, n (%)N = 629cN = 628OR (99% CI)
 Respiratory distress syndrome591 (94)581 (93)1.26 (0.70 to 2.25)
 Chronic lung disease262 (42)235 (37)1.19 (0.89 to 1.61)
 Persistent ductus arteriosus192 (31)195 (31)0.98 (0.71 to 1.34)
 Necrotizing enterocolitis128 (20)103 (16)1.30 (0.89 to 1.90)
 Hyperbilirubinemia522 (83)519 (83)1.03 (0.70 to 1.51)
 Infants with ≥1 acquired infections283 (45)258 (41)1.03 (0.92 to 1.16)
 Cerebral pathology closest to 34 wk0.94 (0.62 to 1.44)d
  Porencephalic cyst9 (1)7 (1)
  Cystic periventricular leukomalacia13 (2)12 (2)
  Ventriculomegaly27 (4)38 (6)
  Miscellaneous37 (6)26 (4)
  More than 1 pathology7 (1)6 (1)
  No abnormalities detected385 (61)392 (62)Reference category
  Missing data153 (24)147 (23)
Hearing and vision impairment in survivors only, n (%)OR (99% CI)
 Deaf or requires hearing aids15/551 (3)14/542 (3)1.06 (0.40 to 2.79)
 Blind or difficulty seeing even with glasses9/551 (2)14/541 (3)0.63 (0.21 to 1.90)
Level of nursing care in survivors only, n (%)OR (99% CI)
 Postnatal day 7N = 613eN = 615e
  Level 1323 (51)321 (51)1.01 (0.85 to 1.20)
  Level 2206 (33)212 (34)1.03 (0.86 to 1.23)
  Level 384 (13)82 (13)Reference category
 Postnatal day 14N = 598N = 596
  Level 1230 (37)219 (35)1.05 (0.90 to 1.22)
  Level 2200 (32)230 (37)1.15 (0.99 to 1.33)
  Level 3168 (27)147 (23)Reference category
 Postnatal day 28N = 583N = 577
  Level 1137 (22)131 (21)1.01 (0.86 to 1.17)
  Level 2216 (34)228 (36)1.06 (0.93 to 1.20)
  Level 3230 (37)218 (35)Reference category
 34 corrected wk gestationN = 564N = 569
  Level 139 (6)33 (5)0.89 (0.69 to 1.16)
  Level 2188 (30)181 (29)0.96 (0.84 to 1.09)
  Level 3337 (53)355 (57)Reference category
Parenteral nutrition as a percentage of total nutrition, mean % ± SD (Nf) in survivors onlyMean difference(99% CI)
 Postnatal day 757.1 ± 37.0 (613)57.2 ± 37.2 (613)−0.11−5.58 to 5.36
 Postnatal day 1423.9 ± 37.5 (597)24.0 ± 37.0 (595)−0.11−5.68 to 5.46
 Postnatal day 2813.5 ± 31.0 (575)13.2 ± 30.6 (575)0.26−4.42 to 4.95
 34 corrected wk gestation8.8 ± 26.1 (558)8.4 ± 24.9 (565)0.38−3.55 to 4.30
  • a Intention-to-treat population includes deaths and severely disabled infants, which were coded 55 for the cognitive score, 47 for the language composite score, and 46 for the motor composite score. Missing outcomes for losses to follow-up and for infants who were withdrawn but allowed their data to be used were imputed.

  • b In the 4 Bayley-III subtest scores, deaths were scored as 1 or 0, reflecting their minimum scores.

  • c Two infants had no postnatal data collection forms.

  • d The OR was any cerebral pathology compared with no cerebral pathology.

  • e N varies due to deaths or to infant withdrawals.

  • f N varies due to deaths, infant withdrawals, and missing data.