Table 1

Characteristics of study sample at baseline (T0)

TotalFull HPSFPartial HPSFControlX2/F valueP value
N*%/
mean (±SD)
N%/
mean (±SD)
N%/
mean (±SD)
N%/
mean (±SD)
Gender (% boys)167647.4%53747.7%47847.3%66147.2% 0.029†0.986
Age (years)16767.5 (±2.16)5377.6 (±2.16)4787.4 (±2.22)6617.6 (±2.13) 1.6100.200
Study year‡16764.0 (±2.00)5374.0 (±2.00)4783.8 (±2.01)6614.1 (±1.99) 2.5260.080
Ethnicity (% Western)101694.1%34193.0%32696.0%34993.4% 3.239†0.198
SES (%)
 Lowest tertile111732.6%36128.8%36532.3%39136.3% 5.636†0.228
 Middle tertile34.0%35.7%35.6%30.9%
 Highest tertile33.4%35.5%32.1%32.7%
BMI z-score11090.135 (±1.02)3210.051 (±1.01)3520.092 (±0.95)4360.232 (±1.07) 3.399 0.034
Overweight/obese (%)110919.9%32116.5%35217.9%43624.1%14.156† 0.006
  • Bold p value=significant (<0.05) difference.

  • *Observed N, missing data were due to later participation in the study, incomplete parent questionnaire, or because no height/weight was measured in study year 1.

  • †X2 test.

  • ‡Study year 1–8 in Dutch system is comparable to 2 years of kindergarten followed by grades 1–6.

  • BMI, body mass index; HPSF, Healthy Primary School of the Future; SES, socioeconomic status.