TABLE 2.

Characteristics of Case Subjects (Undervaccinated Children) and Control Subjects (Fully Vaccinated Children)

CharacteristicUndervaccinated, % (95% CI)Fully Vaccinated, % (95% CI)z Score P Value
Child characteristics
 Gender
  Male53.2 (45.9–60.4)50.8 (44.7–56.8).62
  Female46.9 (39.6–54.1)49.2 (43.2–55.3).62
 Age of child
  19–24 mo37.8 (30.9–44.8)33.8 (27.9–39.7).38
  25–29 mo30.6 (23.7–37.5)29.9 (24.6–35.2).87
  30–35 mo31.6 (25.0–38.2)36.3 (30.6–42.1).29
 Firstborn
  Yes31.8 (25.1–38.4)43.4 (37.5–49.3).01
  No68.3 (61.6–74.9)56.6 (50.7–62.5).01
Mother’s characteristics
 Mother’s age
  ≤19 y4.7 (1.5–8.0)1.8 (0.5–3.1).10
  20–29 y50.2 (42.9–57.4)47.4 (41.5–53.4).57
  ≥30 y45.1 (37.9–52.3)50.7 (44.8–56.7).24
 Education of mother
  <12 y21.7 (15.5–28.0)14.4 (9.4–19.4).07
  12 y37.2 (30.2–44.2)35.4 (29.5–41.2).70
  Some college11.7 (8.0–15.4)17.9 (13.0–22.8).05
  College graduate29.4 (22.6–36.2)32.3 (27.3–37.4).50
 Mother’s marital status
  Widowed/separated/divorced12.4 (7.9–16.9)8.6 (3.7–13.4).26
  Never married28.9 (21.8–36.1)23.4 (18.3–28.4).21
  Married58.7 (51.4–66.0)68.1 (62.0–74.2).05
 Race of mother
  White46.0 (39.0–53.0)58.7 (52.7–64.6).01
  Black22.9 (16.1–29.7)15.2 (11.1–19.3).06
  Hispanic28.2 (21.6–34.8)21.6 (16.1–27.2).14
  American Indian0.6 (0.1–1.2)0.9 (0.3–1.4).54
  Asian2.3 (0.4–4.2)3.7 (0.5–6.9).46
  Other0.00.0
Household characteristics
 Income
  $0 to $30 00060.9 (53.5–68.3)42.1 (35.5–48.6)<.001
  $30 001 to $50 00020.0 (13.4–26.5)21.5 (16.5–26.4).72
  $50 001 to $75 0009.0 (5.7–12.3)17.9 (13.2–22.5)<.001
  ≥$75 00110.2 (6.3–14.1)18.6 (14.0–23.2).01
 No. of people in household
  23.3 (0.7–5.9)4.4 (1.2–7.6).59
  317.4 (12.1–22.6)25.6 (20.6–30.5).03
  434.0 (27.4–40.5)40.3 (34.2–46.3).17
  522.5 (15.9–20.1)14.4 (11.1–17.7).03
  ≥622.9 (16.6–29.3)15.3 (10.9–19.7).05
 No. of children in household
  119.8 (14.3–25.3)30.0 (24.6–35.4).01
  2 or 361.2 (54.1–68.3)60.5 (54.8–66.3).89
  ≥419.0 (12.9–25.2)9.5 (6.6–12.4).01
  Unknown0.00.0
 Shot card availability
  Yes45.0 (37.9–52.1)52.1 (46.1–58.1).13
  No55.0 (47.9–62.1)47.9 (41.9–53.9).13
 No. of providers
  155.3 (48.2–62.4)70.1 (64.6–75.6)<.001
  ≥244.7 (37.6–51.8)29.9 (24.4–35.4)<.001
 Type of provider
  All public20.4 (14.3–26.6)11.9 (8.8–15.0).02
  All hospital5.5 (2.7–8.2)8.6 (5.6–11.6).13
  All private44.6 (37.7–51.6)55.8 (49.8–61.8).02
  All military/other2.8 (0.9–4.7)0.5 (0–1.1).03
  Mixed3.7 (0–7.7)7.5 (4.5–10.6).14
  Unknown23.0 (17.3–28.8)15.7 (10.4–20.9).06
 Mobility
  Moved15.2 (9.5–20.9)7.3 (4.1–10.5).02
 Did not move84.8 (79.1–90.5)92.7 (89.5–95.9).02
 Respondent relationship
  Mother84.7 (79.4–90.0)87.5 (83.5–91.5).41
  Father11.8 (6.9–16.7)10.1 (6.4–13.8).59
 Other3.5 (1.0–6.1)2.4 (0.9–4.0).46