TABLE 1

Comparison of Characteristics Between Responders and Nonresponders

Proportion, %P
Nonresponders (n = 404)Responders (n = 1960)
Gestational age at birth(n = 404)(n = 1960)<.001
    24–26 wk3.67.1
    27–28 wk10.616.5
    29–30 wk27.624.9
    31–32 wk59.251.5
Infant gender(n = 404)(n = 1960).13
    Female43.547.7
Plurality(n = 404)(n = 1960)<.05
    Singleton74.668.2
    Twins22.327.3
    Triplets and quadruplets3.14.5
Cerebral hemorrhage(n = 377)(n = 1935).14
    No81.476.7
    Grade I–II IVH16.020.2
    Grade III IVH or IPH2.63.1
Cystic PVL(n = 377)(n = 1936).37
    Yes2.93.8
Maternal age(n = 404)(n = 1944)<.001
    14–19 y11.73.3
    20–29 y47.853.0
    30–34 y22.427.7
    ≥35 y18.116.0
Parity(n = 401)(n = 1946)<.001
    044.353.7
    1 or 237.736.2
    ≥318.010.1
Marital status(n = 299)(n = 1745)<.001
    Married42.958.4
    Nonmarried cohabiting42.933.5
    Single14.38.1
Educational levela(n = 277)(n = 1646).005
    I9.85.8
    II48.842.7
    III18.220.8
    IV23.230.7
  • a Education was classified into 4 levels, from level I (no schooling or primary level) to level IV (university level).