TABLE 1

Characteristics of Study Population (n = 2099)a

Entire PopulationGroup 1Group 2Group 3Group 4Group 5P
Label UnitmLmL and tspmL and teaspoonmLteaspoon
Dosing Tool UnitmLmL and tspmL and tspmL and tspmL and tsp
N = 417N = 425N = 421N = 418N = 418
Mean (SD) or n (%)Mean (SD) or n (%)Mean (SD) or n (%)Mean (SD) or n (%)Mean (SD) or n (%)Mean (SD) or n (%)
Child characteristics
 Age, y, mean (SD)2.0 (2.2)2.1 (2.2)2.3 (2.3)2.0 (2.1)2.0 (2.1)1.9 (2.1).2
 Gender, n (%) female987 (47.0)206 (49.4)210 (49.4)196 (46.6)181 (43.3)194 (46.4).4
 Chronic medical problem treated with medication, n (%)b352 (16.8)74 (17.7)64 (15.1)64 (15.2)76 (18.2)74 (17.7).6
Parent characteristics
 Age, y, mean (SD)30.0 (7.3)29.9 (7.1)30.2 (7.5)29.1 (7.1)29.8 (7.5)29.5 (7.5).3
 Gender, n (%) female1930 (91.9)384 (92.1)397 (93.4)391 (92.9)384 (91.9)374 (89.5).3
 Relationship to child, n (%) mother1881 (89.6)376 (90.2)384 (90.4)379 (90.0)375 (89.7)367 (87.8).8
 Marital status single, n (%)c803 (38.7)160 (38.8)166 (39.6)157 (37.7)167 (40.3)153 (37.0).9
 Income, n (%).02
  <$10 000497 (23.7)113 (27.1)99 (23.3)85 (20.2)104 (24.9)96 (23.0)
  $10 000–$19 999554 (26.4)94 (22.5)114 (26.8)144 (34.2)107 (25.6)95 (22.7)
  $20 000–$39 999583 (27.8)109 (26.1)122 (28.7)107 (25.4)111 (26.6)134 (32.1)
  ≥$40 000255 (12.1)55 (13.2)47 (11.1)48 (11.4)56 (13.4)49 (11.7)
  Unknown or missing210 (10.0)46 (11.0)43 (10.1)37 (8.8)40 (9.6)44 (10.5)
 Country of birth: non-US born, n (%)d1031 (49.5)203 (49.2)230 (54.4)201 (48.2)201 (48.2)196 (47.3).3
 Race or ethnicity, n (%)e.9
  Hispanic1140 (54.8)224 (54.4)227 (53.8)225 (54.2)241 (57.8)223 (53.9)
  Non-Hispanic
   White, non-Hispanic79 (3.8)14 (3.4)14 (3.3)15 (3.6)18 (4.3)18 (4.3)
   Black, non-Hispanic695 (33.4)141 (34.2)146 (34.6)134 (32.3)134 (32.1)140 (33.8)
   Other, non-Hispanic166 (8.0)33 (8.0)35 (8.3)41 (9.9)24 (5.8)33 (8.0)
 Language Spanish, n (%)f736 (35.1)157 (37.6)158 (37.2)134 (31.8)145 (34.7)142 (34.0).4
 Education, n (%)g.9
  Less than high school graduate638 (30.7)132 (32.0)137 (32.5)118 (28.3)128 (30.8)123 (29.7)
  High school graduate or equivalent674 (32.4)127 (30.8)141 (33.4)138 (33.1)138 (33.3)130 (31.4)
  Higher than high school graduate769 (37.0)154 (37.3)144 (34.1)161 (38.6)149 (35.9)161 (38.9)
 Health literacy, n (%)h.04
  Low740 (36.0)148 (36.5)139 (33.4)142 (34.6)157 (38.1)154 (37.2)
  Marginal843 (41.0)166 (40.9)191 (45.9)167 (40.7)175 (42.5)144 (34.8)
  Adequate475 (23.1)92 (22.7)86 (20.7)101 (24.6)80 (19.4)116 (28.0)
Site characteristics
 Emory690 (32.9)137 (32.9)140 (32.9)138 (32.8)137 (32.8)138 (33.0).97
 New York University701 (33.4)141 (33.8)141 (33.2)140 (33.3)139 (33.3)140 (33.5)
 Stanford708 (33.7)139 (33.3)144 (33.9)143 (34.0)142 (34.0)140 (33.5)
  • a Characteristics not different between enrolled subjects and those eligible who did not enroll (P > .05 for all).

  • b Missing for 56 children overall (16 in group 1, 11 in group 2, 12 in group 3, 5 in group 4, and 12 in group 5).

  • c Missing for 25 parents (5 in group 1, 6 in group 2, 5 in group 3, 4 in group 4, and 5 in group 5).

  • d Missing for 15 parents (4 in group 1, 2 in group 2, 4 in group 3, 1 in group 4, and 4 in group 5).

  • e Missing for 19 parents (5 in group 1, 3 in group 2, 6 in group 3, 1 in group 4, and 4 in group 5).

  • f Language of survey administration.

  • g Missing for 18 parents (4 in group 1, 3 in group 2, 4 in group 3, 3 in group 4, 4 in group 5).

  • h Health literacy measured with the Newest Vital Sign (low = score 0–1, marginal = 2–3, adequate = 4–6). Data missing for 41 subjects who did not complete the Newest Vital Sign (11 in group 1, 9 in group 2, 11 in group 3, 6 in group 4, and 4 in group 5).