Table 5.
Risk factors for recovery from baseline iron deficiency anemia (IDA) in the postpartum period (Hb/MCV recovery)
| No. of recovered IDA patients | Univariate rate ratio (95% CI)a | P-valuea | Multivariate rate ratio (95% CI)a | P-valuea | |
|---|---|---|---|---|---|
| Maternal age (years) <20 | 277 | 0.81 (0.71, 0.93) | 0.001b | 0.8 (0.7, 0.92) | 0.04b |
| 20–24 | 802 | 1.0 | 1.0 | ||
| 25–29 | 583 | 1.09 (0.98, 1.21) | 1.04 (0.94, 1.16) | ||
| ≥30 | 369 | 1.10 (0.98, 1.25) | 1.11 (0.98, 1.26) | ||
| Baseline BMI (kg/m2) | |||||
| <22 | 530 | 0.97 (0.87, 1.09) | 0.71b | ||
| 22–24.99 | 685 | 1.0 | |||
| 25–29.99 | 479 | 0.97 (0.86, 1.09) | |||
| ≥30 | 114 | 1.00 (0.82, 1.22) | |||
| Postpartum BMI (kg/m2)c | |||||
| <22 | 640 | 0.91 (0.81, 1.02) | 0.02d | 0.93 (0.83, 1.05) | 0.30b |
| 22–24.99 | 535 | 1.0 | 1.0 | ||
| 25–29.99 | 353 | 1.07 (0.94, 1.22) | 1.09 (0.94, 1.27) | ||
| ≥30 | 68 | 0.80 (0.62, 1.03) | 0.82 (0.62, 1.07) | ||
| Baseline MUAC | |||||
| >Median | 672 | 1.0 | 0.47b | ||
| ≤Median | 1372 | 0.99 (0.90, 1.09) | |||
| Postpartum MUACc | |||||
| >Median | 479 | 1.0 | 0.009d | 1.0 | 0.12b |
| ≤Median | 1565 | 0.98 (0.88, 1.09) | 0.93 (0.81, 1.07) | ||
| No. of previous pregnancies | |||||
| 0 (Primigravida) | 889 | 1.0 | 0.57b | ||
| 1 | 572 | 1.07 (0.96, 1.19) | |||
| 2 | 318 | 1.10 (0.97, 1.25) | |||
| ≥3 | 253 | 0.99 (0.87, 1.14) | |||
| Weeks gestation at baseline | |||||
| ≥Median | 776 | 0.97 (0.89, 1.06) | 0.71b | ||
| <Median | 1268 | 1.0 | |||
| Baseline CD4 count | |||||
| ≥500 | 758 | 1.0 | |||
| <500 | 1286 | 0.97 (0.77, 1.21) | 0.26b | ||
| Postpartum CD4 countc | |||||
| ≥500 | 1115 | 1.0 | 1.0 | ||
| <500 | 929 | 1.20 (0.95, 1.51) | 0.002b | 1.04 (0.82, 1.31) | 0.25b |
| Socio-economic characteristics | |||||
| Per day spending for food | |||||
| >500 | 767 | 1.0 | |||
| ≤500 | 1277 | 1.05 (0.96, 1.16) | 0.27 | ||
| Marital status | |||||
| Married | 669 | 1.0 | |||
| Other | 1375 | 0.98 (0.90, 1.08) | 0.73 | ||
| Education status | |||||
| 0–4 | 256 | 0.78 (0.62, 0.98) | 0.02b | 0.76 (0.60, 0.95) | 0.01b |
| 5–7 | 1314 | 0.84 (0.69, 1.02) | 0.83 (0.68, 1.02) | ||
| 8–11 | 353 | 0.91 (0.73, 1.12) | 0.97 (0.78, 1.20) | ||
| 12 or more | 110 | 1.0 | 1.0 | ||
| Owns/possesses | |||||
| Sofa | 1442 | 1.04 (0.95, 1.15) | 0.39 | ||
| No | 602 | 1.0 | |||
| Television | 717 | 1.06 (0.97, 1.16) | 0.20 | ||
| No | 1327 | 1.0 | |||
| Cohabitates with partner | 399 | 1.11 (1.00, 1.24) | 0.07 | 1.11 (0.99, 1.24) | 0.07 |
| No | 1645 | 1.0 | 1.0 | ||
| Radio | 1677 | 1.02 (0.91, 1.14) | 0.77 | ||
| No | 367 | 1.0 | |||
| Refrigerator | 446 | 1.04 (0.93, 1.15) | 0.51 | ||
| No | 1598 | 1.0 | |||
| Fan | 973 | 1.03 (0.95, 1.13) | 0.45 | ||
| No | 1071 | 1.0 | |||
| Filmer–Pritchett wealth score | |||||
| ≥Median | 1006 | 1.0 | |||
| <Median | 1038 | 0.95 (0.87, 1.03) | 0.22 | ||
| Dietary characteristics | |||||
| Consumed alcohol at enrollment | 185 | 0.91 (0.78, 1.07) | 0.25 | ||
| No alcohol | 1034 | 1.0 | |||
| History of meat use at enrollment | |||||
| At least one per month | 611 | 1.08 (0.98, 1.18) | 0.13 | 1.14 (1.03, 1.25) | 0.009 |
| Less | 1433 | 1.0 | 1.0 | ||
| History of soil use at enrollment: | |||||
| At least one per month | 1812 | 1.29 (1.12, 1.48) | 0.0004 | 1.21 (1.05, 1.39) | 0.007 |
| Less | 232 | 1.0 | 1.0 | ||
| Fe sups adherence during pregnancy | |||||
| ≤Median | 1597 | 1.08 (0.97, 1.20) | 0.15 | 1.20 (1.07, 1.34) | 0.002 |
| >Median | 447 | 1.0 | 1.0 | ||
| Breastfeeding since last visit | |||||
| Yes | 56 | 0.90 (0.69, 1.17) | 0.43 | ||
| No | 1988 | 1.0 | |||
| Iron intakec | |||||
| Tertile 1 | 46 | 1.0 | 0.13b | 1.0 | 0.65b |
| Tertile 2 | 39 | 0.90 (0.58, 1.37) | 0.89 (0.50, 1.60) | ||
| Tertile 3 | 31 | 0.71 (0.45, 1.12) | 0.66 (0.30, 1.46) | ||
| Vitamin C intakec | |||||
| Tertile 1 | 36 | 1.0 | 0.14b | 1.0 | 0.40b |
| Tertile 2 | 32 | 0.78 (0.51, 1.20) | 0.90 (0.56, 1.45) | ||
| Tertile 3 | 48 | 0.74 (0.47, 1.16) | 0.85 (0.49, 1.48) | ||
| Vitamin B12 intakec | |||||
| Tertile 1 | 9 | 1.0 | 0.75b | ||
| Tertile 2 | 37 | 0.45 (0.22, 0.89) | |||
| Tertile 3 | 70 | 0.95 (0.64, 1.42) | |||
| Vitamin B6 intakec | |||||
| Tertile 1 | 41 | 1.0 | 0.04b | 1.0 | 0.89b |
| Tertile 2 | 31 | 0.88 (0.57, 1.34) | 1.09 (0.64, 1.87) | ||
| Tertile 3 | 44 | 0.78 (0.49, 1.23) | 1.27 (0.63, 2.58) | ||
| Folate intakec | |||||
| Tertile 1 | 31 | 1.0 | 0.03b | 1.0 | 0.17b |
| Tertile 2 | 36 | 0.69 (0.44, 1.08) | 0.81 (0.48, 1.37) | ||
| Tertile 3 | 49 | 0.76 (0.49, 1.16) | 1.02 (0.55, 1.90) | ||
| Heme iron intakec | |||||
| Tertile 1 | 96 | 1.0 | 0.50b | ||
| Tertile 2 | 19 | 1.04 (0.64, 1.70) | |||
| Tertile 3 | 1 | 4.50 (0.63, 32.37) | |||
| Medical characteristics | |||||
| History of eclampsia | 15 | 1.12 (0.68, 1.87) | 0.65 | ||
| No | 2029 | 1.0 | |||
| Fansidar this pregnancy | 355 | 1.03 (0.92, 1.15) | 0.64 | ||
| No | 1689 | 1.0 | |||
| Diarrhea this pregnancy | 72 | 0.87 (0.69, 1.10) | 0.26 | ||
| No | 1972 | 1.0 | |||
| Vaginal bleeding this pregnancy | 81 | 0.99 (0.79, 1.24) | 0.92 | ||
| No | 1963 | 1.0 | |||
| Malaria this pregnancy (prior to enrollment) | 566 | 0.99 (0.90, 1.10) | 0.92 | ||
| No | 1478 | 1.0 | |||
| Presumptive malariac | 16 | 0.76 (0.46, 1.24) | 0.27 | ||
| No | 2028 | 1.0 | |||
| Postpartum malariac | 561 | 1.20 (1.09, 1.33) | 0.0003 | 1.02 (0.92, 1.13) | 0.75 |
| No | 1483 | 1.0 | 1.0 | ||
| Chlamydia | 2 | 0.32 (0.08, 1.26) | 0.10 | 0.28 (0.07, 1.14) | 0.08 |
| No | 2042 | 1.0 | 1.0 | ||
| Delivery characteristics | |||||
| Delivery type | |||||
| Spontaneous vaginal delivery | 1867 | 1.0 | 1.0 | ||
| Other | 168 | 0.79 (0.68, 0.93) | 0.004 | 0.76 (0.65, 0.90) | 0.0009 |
| Blood loss (hemorrhage/transfusion at delivery) | 14 | 0.92 (0.54, 1.56) | 0.76 | ||
| No | 2030 | 1.0 | |||
Abbreviations: BMI, body mass index;
a
CI, confidence interval; Fe sups, iron supplements; Hb, hemoglobin; MCV, mean corpuscular volume; TSh, Tanzanian shillings. Risk ratio, confidence intervals and P-values are from Cox proportional hazards models.
b
P-value corresponds to trend test.
c
Time-varying covariates. Analysis performed using Andersen–Gill data structure with 7127 observations during follow-up period.
d
Association was significantly nonlinear. P-value corresponds to the test of overall significance.