TABLE 2.
RRs (95% CIs) for mortality for continuous and categorical growth velocity z scores of 5657 children <5 y of age included in a cohort study in Bwamanda, Democratic Republic of Congo (1989–1991), after GEE-based regression1
| Index and category | n | RR (95% CI)2 | Adjusted RR (95% CI)3 |
| Continuous | |||
| WVZ | — | 1.49 (1.37, 1.62) | 1.49 (1.30, 1.71) |
| LVZ | — | 1.41 (1.30, 1.53) | 1.24 (1.06, 1.45) |
| ΔMUACZ | — | 1.90 (1.60, 2.26) | 2.28 (1.74, 2.99) |
| ΔabsMUAC | — | 1.87 (1.51, 2.31) | 2.40 (1.84, 3.14) |
| WVZ | |||
| Reference | 1736 | 1 | 1 |
| Mild | 2688 | 1.34 (0.72, 2.51) | 1.39 (0.73, 2.66) |
| Moderate | 521 | 2.36 (1.06, 5.25) | 2.65 (1.17, 6.04) |
| Severe | 349 | 6.70 (3.42, 13.12) | 7.92 (3.87, 16.19) |
| LVZ | |||
| Reference | 2741 | 1 | 1 |
| Mild | 1106 | 5.81 (2.14, 15.73) | 5.82 (2.13, 15.94) |
| Moderate | 622 | 5.82 (1.89, 17.97) | 5.86 (1.86, 18.48) |
| Severe | 603 | 11.70 (4.13, 33.17) | 11.80 (3.92, 35.54) |
| ΔMUACZ | |||
| Reference | 6199 | 1 | 1 |
| Mild | 4029 | 1.42 (0.82, 2.46) | 1.80 (1.03, 3.15) |
| Moderate | 2347 | 2.12 (1.20, 3.75) | 3.10 (1.69, 5.68) |
| Severe | 1486 | 3.66 (2.10, 6.38) | 6.25 (3.26, 11.98) |
| ΔabsMUAC | |||
| Reference | 8718 | 1 | 1 |
| Mild | 4214 | 1.68 (1.01, 2.79) | 2.59 (1.54, 4.37) |
| Moderate | 2504 | 1.97 (1.13, 3.43) | 3.80 (2.08, 6.98) |
| Severe | 1325 | 2.74 (1.50, 5.01) | 6.13 (3.18, 11.82) |
z Score categories for WVZ and LVZ are defined as follows: reference group, ≥0; mild, <0 but ≥−2; moderate, <−2 but ≥−3; and severe, <−3. For the MUAC-based indexes, these are as follows: reference, ≥0; mild, <0 but ≥−0.5; moderate, <−0.5 but ≥−1; and severe, <−1. GEE, generalized estimating equation; LAZ, length-for-age z score; LVZ, length velocity z score; MUAC, midupper arm circumference; WLZ, weight-for-length z score; WVZ, weight velocity z score; ΔabsMUAC, change in absolute midupper arm circumference; ΔMUACZ, change in midupper arm circumference-for-age z score.
For simplicity, continuous variables are converted so that 1 unit is a decrease in 1 z score. The RR represents the risk of death with each z score falling under the z score of 0. For absolute MUAC, the RR represents the risk of death for every centimeter decrease compared with an MUAC of ≥12.5 cm.
Adjusted for attained growth (WLZ, LAZ, or MUAC, respectively) at the beginning of the increment period.