TABLE 2

Percentage With Low (–2 SD) and High (2+ SD) Age-Specific z Scores and 95% Confidence Intervals for Anthropometric Indicators Among US Children Aged 6 to 23 Months, 1976 to 2014

1976–19801988–19941999–20022003–20062007–20102011–2014P for Trenda
Weight-for-age
z score < –20.6 (0.2–1.5)b0.5 (0.2–0.9)c1.4 (0.6–2.8)c1.8 (0.9–3.3)1.0 (0.5–2.0)c0.6 (0.2–1.5)b.17
z score 2+5.6 (4.0–7.7)6.0 (4.8–7.4)5.9 (4.6–7.4)6.0 (4.1–8.3)6.3 (4.5–8.6)7.0 (5.0–9.5).37
Length-for-age
z score < –24.4 (3.0–6.2)2.7 (1.9–3.8)4.6 (3.2–6.5)3.1 (1.8–4.9)3.1 (2.2–4.2)3.3 (1.9–5.4).35
z score 2+5.5 (4.1–7.1)5.0 (4.3–5.8)4.1 (3.0–5.6)4.0 (2.3–6.5)3.9 (2.1–6.5)3.7 (2.2–5.7).04
Weight-for-length
z score < –20.4 (0.1–1.1)b0.8 (0.4–1.2)0.6 (0.1–1.9)b1.0 (0.4–2.1)c0.6 (0.1–1.7)b1.0 (0.3–2.3)b.28
z score 2+6.2 (4.4–8.4)7.0 (5.8–8.5)7.6 (5.8–9.8)7.4 (5.3–10.0)8.7 (6.8–10.9)7.7 (5.5–10.4).12
  • Data source: NHANES.

  • a Trends tested by using orthogonal contrast matrices.

  • b Relative SE >40%, numerator <10.

  • c Relative SE 30% to 40%.