TABLE 6

Characteristics of the 4 Clusters for Longitudinal Changes in PPVT-R Raw Scores

Cluster A'Cluster B'Cluster C'Cluster D'
N841011116
Proportion of total preterm cohort (N = 302), %2833372
Child characteristics
    Gestational age, mean (SD), wk27.9 (2.2)27.9 (1.8)28.0 (1.9)28.0 (2.3)
    Birth weight, mean (SD), g929 (186)973 (153)967 (184)884 (176)
    Male gender, n (%)42 (50)59 (58)60 (54)5 (83)
    Multiple, n (%)20 (24)27 (27)18 (16)0 (0)
    Small for gestational age, n (%)19 (23)22 (22)31 (28)2 (33)
    Maternal steroids, n (%)27 (32)41 (41)38 (34)1 (17)
    Indomethacin, n (%)38 (46)48 (49)62 (56)3 (60)
    Bronchopulmonary dysplasia, n (%)41 (49)47 (47)48 (43)5 (83)
    Neonatal brain injury, n (%)
        None64 (76)78 (77)82 (74)2 (33)
        Severe brain injurya5 (6)9 (9)7 (6)4 (67)
    NSI, n (%)12 (14)9 (9)14 (13)6 (100)
Family factors
    Maternal age at birth, mean (SD), y28.9 (6.3)28.0 (5.9)27.2 (6.0)27.4 (6.5)
    Maternal education, n (%)
        High school or less28 (33)41 (41)48 (44)3 (50)
        ≥1 year of college56 (67)60 (59)62 (56)3 (50)
    Race and ethnicity, n (%)
        Non-Hispanic white54 (64)79 (78)70 (64)5 (83)
        Other30 (36)22 (22)40 (36)1 (17)
    Bilingual environment, n (%)13 (15)12 (12)14 (13)2 (33)
    Single-parent household at 16 y, n (%)20 (24)33 (33)44 (40)1 (17)
  • a Severe brain injury includes grades 3 to 4 intraventricular hemorrhage, periventricular leukomalacia, and grade 2 and above ventriculomegaly.