Table 1

Salt and iodine intake as calculated from 24 hour urinary sodium and iodine excretion based on intention-to-treat analysis

ControlIntervention
OutcomeBaseline*End of trial*Change from baseline*Baseline*End of trial*Change from baseline*Mean effect† (intervention vs control)p Value
Children
Salt mean‡ (95% CI) (g/day)6.8 (6.2 to 7.4)8.0 (7.4 to 8.6)1.2 (0.7 to 1.7)7.3 (6.7 to 7.9)6.6 (6.0 to 7.2)−0.7 (−1.2 to −0.2)−1.9 (−2.6 to −1.3)<0.0001
Iodine
 Geometric mean (95% CI) (µg/day)162.8 (146.7 to 180.5)187.5 (168.9 to 208.0)115.2% (104.7% to 126.7%)173.7 (156.7 to 192.4)163.2 (147.2 to 180.9)94.0% (85.6% to 103.2%)−19.3% (−29.4% to −7.7%)0.002
 Median (IQR) (µg/day)161.7 (117.7 to 209.5)176.0 (136.5 to 237.2)27.4 (−18.3 to 76.7)167.0 (128.9 to 217.7)154.8 (118.6 to 234.1)−13.1 (−54.5 to 37.8)
Adults
Salt mean (95% CI) (g/day)11.3 (10.5 to 12.1)12.1 (11.3 to 12.9)0.8 (0.2 to 1.3)12.6 (11.8 to 13.3)10.4 (9.7 to 11.2)−2.1 (−2.7 to −1.6)−2.9 (−3.7 to −2.2)<0.0001
Iodine
 Geometric mean (95% CI) (µg/day)271.2 (245.1 to 300.1)284.6 (256.9 to 315.2)104.9% (97.2% to 113.3%)291.2 (263.3 to 322.1)271.9 (245.7 to 301.0)93.4% (86.6% to 100.7%)−11.4% (−20.3% to −1.5%)0.030
 Median (IQR) (µg/day)262.1 (197.8 to 357.5)281.3 (207.9 to 387.6)10.7 (−72.8 to 105.3)297.4 (213.2 to 390.8)258.5 (199.8 to 350.0)−36.5 (−128.4 to 88.9)
  • *Mean and geometric mean were adjusted for stratification variables at randomisation (school location and class size).

  • †Adjusted for age, sex, body mass index, stratification variables at randomisation (school location and class size), and indoor and outdoor temperature.

  • ‡The results for salt were taken from previous report.14