Table 2. Comparison of Fluoride Exposure Across Groups.
| Fluoride exposurea | 2013-2014 Cycle | 2015-2016 Cycle | ||||
|---|---|---|---|---|---|---|
| Weighted No. (%) | Mean (SD) | Mean difference (95% CI) | Weighted No. (%) | Mean (SD) | Mean difference (95% CI) | |
| Water fluoride concentration, mg/L | ||||||
| All | 31 847 426 (100) | 0.56 (0.36) | NA | 32 340 232 (100) | 0.46 (0.38) | NA |
| Children | 17 179 395 (53.9) | 0.55 (0.34) | −0.025 (−0.096 to 0.045) | 17 025 031 (52.6) | 0.49 (0.40) | 0.067 (−0.001 to 0.134) |
| Adolescents | 14 668 030 (46.1) | 0.57 (0.39) | 15 315 201 (47.4) | 0.43 (0.34) | ||
| November 1 through April 30 | 15 045 091 (47.2) | 0.55 (0.34) | 0.021 (−0.143 to 0.185) | 13 969 779 (43.2) | 0.41 (0.40) | −0.099 (−0.273 to 0.074) |
| May 1 through October 31 | 16 802 334 52.8 | 0.57 (0.39) | 18 370 453 (56.8) | 0.50 (0.35) | ||
| Plasma fluoride concentration, μmol/L | ||||||
| All | 31 847 426 (100) | 0.43 (0.48) | NA | 32 340 232 (100) | 0.35 (0.22) | NA |
| Children | 17 179 395 (53.9) | 0.44 (0.27) | 0.026 (−0.022 to 0.074) | 17 025 031 (52.6) | 0.38 (0.23) | 0.054 (0.030 to 0.079) |
| Adolescents | 14 668 030 (46.1) | 0.42 (0.69) | 15 315 201 (47.4) | 0.32 (0.20) | ||
| November 1 through April 30 | 15 045 091 (47.2) | 0.40 (0.24) | −0.004 (−0.081 to 0.071) | 13 969 779 (43.2) | 0.35 (0.27) | −0.002 (−0.055 to 0.051) |
| May 1 through October 31 | 16 802 334 (52.8) | 0.47 (0.65) | 18 370 453 (56.8) | 0.35 (0.17) | ||
| Fluoride supplement use | ||||||
| All | 460 6497 (100) | NA | NA | 4 038 972 (100) | NA | NA |
| Children | 2 266 345 (49.2) | NA | NA | 1 874 254 (46.4) | NA | NA |
| Adolescents | 2 340 152 (50.8) | NA | 2 164 717 (53.6) | NA | ||
| November 1 through April 30 | 1 486 602 (32.3) | NA | NA | 2 216 167 (54.9) | NA | NA |
| May 1 through October 31 | 3 119 894 (67.7) | NA | 1 822 805 (45.1) | NA | ||
Abbreviation: NA, not applicable.
a
Children are aged 6 to 11 years; adolescents, aged 12 to 15 years.