Table 3.
Mean changes within each study group between baseline and week 22 with estimates of intervention effect for Hb, MCV, HCT, and RDW-CV, by anthropometric status or sex1.
| Placebo2 | Intervention2 | Intervention effect (95% CI)3 | p-value for interaction | |||
|---|---|---|---|---|---|---|
| n | Mean (95% CI) | n | Mean (95% CI) | |||
| Hb, g/L | ||||||
| By anthropometric status4 | 0.127 | |||||
| Undernourished | 43 | 5.0 (− 4.7, 14.7) | 40 | 13.9 (4.1, 23.7) | 8.9 (− 1.3, 19.2) | |
| Normal weight | 58 | 6.5 (− 2.8, 15.7) | 66 | 10.0 (0.9, 19.0) | 3.5 (− 4.9, 11.9) | |
| Overweight/obese | 52 | 10.1 (0.7, 19.5) | 47 | 7.3 (− 2.2, 16.8) | − 2.9 (− 12.2, 6.5) | |
| By sex | 0.261 | |||||
| Girls | 68 | 6.0 (− 3.1, 15.1) | 68 | 11.7 (2.6, 20.7) | 5.7 (− 1.8, 13.2) | |
| Boys | 85 | 8.3 (− 0.5, 17.2) | 85 | 9.0 (0.1, 17.8) | 0.6 (− 6.1, 7.3) | |
| MCV, fL | ||||||
| By anthropometric status4 | 0.726 | |||||
| Undernourished | 43 | − 1.0 (− 1.3, − 0.7) | 40 | − 0.6 (− 0.9, − 0.3) | 0.4 (− 0.1, 0.9) | |
| Normal weight | 58 | − 1.1 (− 1.4, − 0.8) | 66 | − 0.7 (− 1.0, − 0.5) | 0.4 (− 0.0, 0.8) | |
| Overweight/obese | 52 | − 0.7 (− 1.0, − 0.4) | 47 | − 0.5 (− 0.8, − 0.2) | 0.2 (− 0.2, 0.6) | |
| By sex | 0.623 | |||||
| Girls | 68 | − 1.1 (− 1.4, − 0.9) | 68 | − 0.8 (− 1.0, − 0.5) | 0.4 (0.0, 0.7) | |
| Boys | 85 | − 0.8 (− 1.0, − 0.6) | 85 | − 0.5 (− 0.8, − 0.3) | 0.3 (− 0.0, 0.6) | |
| HCT, % | ||||||
| By anthropometric status4 | 0.295 | |||||
| Undernourished | 43 | − 1.7 (− 3.7, 0.4) | 40 | 0.5 (− 1.6, 2.6) | 2.2 (− 0.4, 4.7) | |
| Normal weight | 58 | − 1.3 (− 3.2, 0.6) | 66 | − 0.1 (− 1.9, 1.8) | 1.2 (− 0.9, 3.3) | |
| Overweight/obese | 52 | − 0.4 (− 2.4, 1.6) | 47 | − 0.5 (− 2.5, 1.5) | − 0.1 (− 2.5, 2.3) | |
| By sex | 0.126 | |||||
| Girls | 68 | − 1.6 (− 3.5, 0.3) | 68 | 0.4 (− 1.4, 2.3) | 2.0 (0.1, 3.9) | |
| Boys | 85 | − 0.7 (− 2.5, 1.1) | 85 | − 0.4 (− 2.2, 1.3) | 0.3 (− 1.4, 2.0) | |
| RDW-CV, % | ||||||
| By anthropometric status4 | 0.411 | |||||
| Undernourished | 43 | − 0.2 (− 0.4, − 0.1) | 40 | − 0.3 (− 0.4, − 0.1) | − 0.0 (− 0.3, 0.2) | |
| Normal weight | 58 | − 0.1 (− 0.3, 0.0) | 66 | − 0.1 (− 0.3, 0.1) | 0.0 (− 0.2, 0.3) | |
| Overweight/obese | 52 | − 0.2 (− 0.4, − 0.1) | 47 | − 0.1 (− 0.2, 0.1) | 0.2 (− 0.1, 0.4) | |
| By sex | 0.801 | |||||
| Girls | 68 | − 0.1 (− 0.3, 0.0) | 68 | − 0.1 (− 0.2, 0.1) | 0.1 (− 0.1, 0.2) | |
| Boys | 85 | − 0.3 (− 0.4, − 0.1) | 85 | − 0.2 (− 0.3, − 0.0) | 0.1 (0.1, 0.2) | |
1All estimates are from linear mixed models including group (intervention/placebo) and anthropometric status (undernourished/normal weight/overweight-obese) or sex (boy/girl), and their interaction (group × anthropometric status; or group × sex) as fixed effects, and school as a random effect.
Hb haemoglobin, HCT haematocrit, MCV mean corpuscular volume, RDW-CV red blood cell distribution width.
2Values are the mean change (95% CI) within each group between baseline and week 22. Positive values indicate within-group increases.
3The intervention effect is the difference in the mean change from baseline to week 22 between the intervention group and the placebo group (Sidak-adjusted 95% CI). Positive values indicate greater positive changes in the intervention group.
4Undernourished defined as either underweight, stunting, or wasting. Underweight defined as weight-for-age z score < -2; stunting as height-for-age z score < -2; and wasting as BMI-for-age z score < -2. Normal weight defined as BMI-for-age z score ≥ -2 and BMI-for-age z score ≤ 1 in the absence of undernutrition. Overweight/obesity defined as BMI-for-age z score > 1 in the absence of undernutrition32.