Table 3.
Risk factors for iron deficiency anemia (IDA) in the postpartum period (Hb <11 and MCV <80)
| No. of IDA patients | Univariate rate (95% CI)a | P-valuea | Multivariate rate ratio (95% CI)a | P-valuea | |
|---|---|---|---|---|---|
| Maternal age (years) <20 | 33 | 1.65 (1.07, 2.54) | 0.06b | 1.35 (0.87, 2.12) | 0.06b |
| 20–24 | 56 | 1.0 | 1.0 | ||
| 25–29 | 43 | 0.92 (0.62, 1.38) | 0.82 (0.54, 1.25) | ||
| ≥30 | 31 | 0.95 (0.61, 1.47) | 0.85 (0.52, 1.38) | ||
| Baseline BMI (kg/m2) | |||||
| <22 | 33 | 1.14 (0.72, 1.80) | 0.17b | 1.29 (0.80, 2.08) | 0.34b |
| 22–24.99 | 41 | 1.0 | 1.0 | ||
| 25–29.99 | 43 | 0.81 (0.53, 1.25) | 1.05(0.66, 1.68) | ||
| ≥30 | 18 | 0.85 (0.49, 1.48) | 1.21 (0.64, 2.30) | ||
| Postpartum BMI (kg/m2)c | |||||
| <22 | 34 | 0.97 (0.60, 1.58) | 0.37b | ||
| 22–24.99 | 31 | 1.0 | |||
| 25–29.99 | 28 | 0.89 (0.53, 1.48) | |||
| ≥30 | 16 | 0.80 (0.44, 1.47) | |||
| Baseline MUAC | |||||
| >Median | 74 | 1.0 | 0.24b | ||
| ≤Median | 90 | 0.80 (0.59, 1.10) | |||
| Postpartum MUACc | |||||
| >Median | 52 | 1.0 | 0.06b | 1.0 | 0.37b |
| ≤Median | 112 | 0.66 (0.46, 0.94) | 0.74 (0.48, 1.14) | ||
| No. of previous pregnancies | |||||
| 0 (primigravida) | 75 | 1.0 | 0.74b | ||
| 1 | 46 | 0.93 (0.64, 1.34) | |||
| 2 | 19 | 0.66 (0.40, 1.09) | |||
| ≥3 | 23 | 1.15 (0.72, 1.83) | |||
| Weeks gestation at baseline | |||||
| ≥Median | 77 | 1.05 (0.78, 1.43) | 0.80b | ||
| <Median | 87 | 1.0 | |||
| Baseline CD4 count | |||||
| ≥500 | 62 | 1.0 | 0.41b | ||
| <500 | 102 | 1.46 (0.67, 3.19) | |||
| Postpartum CD4 countc | |||||
| ≥500 | 85 | 1.0 | 1.0 | ||
| <500 | 79 | 1.40 (0.65, 3.02) | 0.05b | 2.16 (0.98, 4.75) | 0.06b |
| Socio-economic characteristics | |||||
| Per day spending for food | |||||
| >500 | 55 | 1.0 | |||
| ≤500 | 109 | 1.12 (0.80, 1.57) | 0.50 | ||
| Marital status | |||||
| Married | 64 | 1.0 | 1.0 | ||
| Other | 100 | 1.25 (0.91, 1.71) | 0.17 | 1.06 (0.75, 1.49) | 0.74 |
| Education status | |||||
| 0–4 | 15 | 1.49 (0.65, 3.42) | 0.65b | ||
| 5–7 | 104 | 1.23 (0.62, 2.44) | |||
| 8–11 | 35 | 1.50 (0.72, 3.12) | |||
| 12 or more | 9 | 1.0 | |||
| Owns/possesses | |||||
| Sofa | 124 | 0.82 (0.57, 1.18) | 0.29 | ||
| No | 40 | 1.0 | |||
| Television | 70 | 1.12 (0.82, 1.53) | 0.47 | ||
| No | 94 | 1.0 | |||
| Cohabitates with partner | 30 | 0.87 (0.58, 1.29) | 0.49 | ||
| No | 134 | 1.0 | |||
| Radio | 132 | 0.68 (0.46, 1.01) | 0.06 | 0.83(0.55, 1.26) | 0.38 |
| No | 32 | 1.0 | 1.0 | ||
| Refrigerator | 47 | 0.82 (0.58, 1.16) | 0.26 | ||
| No | 117 | 1.0 | |||
| Fan | 95 | 0.94 (0.69, 1.28) | 0.69 | ||
| No | 69 | 1.0 | |||
| Filmer–Pritchett wealth score | |||||
| ≥Median | 61 | 1.0 | |||
| <Median | 103 | 0.97 (0.71, 1.34) | 0.87 | ||
| Dietary characteristics | |||||
| Consumed alcohol at enrollment | 18 | 1.20 (0.72, 2.00) | 0.49 | ||
| No alcohol | 81 | 1.0 | |||
| History of meat use at enrollment | |||||
| At least 1 per month | 40 | 1.06 (0.74, 1.52) | 0.75 | ||
| Less | 124 | 1.0 | |||
| History of soil use at enrollment | |||||
| At least 1 per month | 158 | 1.08 (0.44, 2.65) | 0.86 | ||
| Less | 6 | 1.0 | |||
| Fe sups adherence during pregnancy | |||||
| ≤Median | 50 | 0.43 (0.31, 0.60) | <0.0001 | 0.59 (0.40, 0.87) | 0.008 |
| >Median | 114 | 1.0 | 1.0 | ||
| Breastfeeding since last visit | |||||
| Yes | 3 | 0.72 (0.23, 2.26) | 0.57 | ||
| No | 161 | 1.0 | |||
| Iron intakec | |||||
| Tertile 1 | 4 | 1.0 | 0.48b | ||
| Tertile 2 | 10 | 1.90 (0.60, 6.10) | |||
| Tertile 3 | 8 | 1.51 (0.45, 5.02) | |||
| Vitamin C intakec | |||||
| Tertile 1 | 6 | 1.0 | 0.65b | ||
| Tertile 2 | 9 | 1.34 (0.48, 3.78) | |||
| Tertile 3 | 7 | 1.12 (0.38, 3.33) | |||
| Vitamin B12 intakec | |||||
| Tertile 1 | 14 | 1.0 | 0.13b | 1.0 | 0.07b |
| Tertile 2 | 3 | 0.50 (0.14, 1.75) | 0.57 (0.16, 2.00) | ||
| Tertile 3 | 5 | 0.45 (0.16, 1.24) | 0.78 (0.23, 2.68) | ||
| Vitamin B6 intakec | |||||
| Tertile 1 | 7 | 1.0 | 0.79d | ||
| Tertile 2 | 7 | 0.88 (0.31, 2.51) | |||
| Tertile 3 | 8 | 0.83 (0.30, 2.29) | |||
| Folate intakec | |||||
| Tertile 1 | 6 | 1.0 | 0.48b | ||
| Tertile 2 | 6 | 1.00 (0.32, 3.12) | |||
| Tertile 3 | 10 | 1.43 (0.52, 3.94) | |||
| Heme iron intakec | |||||
| Tertile 1 | 19 | 1.0 | 0.07b | 1.0 | 0.31b |
| Tertile 2 | 3 | 0.48 (0.14, 1.63) | 0.47 (0.11, 2.10) | ||
| Tertile 3 | 0 | — | — | ||
| Medical characteristics | |||||
| History of eclampsia | 1 | 0.53 (0.07, 3.79) | 0.53 | ||
| No | 163 | 1.0 | |||
| Fansidar this pregnancy | 25 | 0.73 (0.48, 1.12) | 0.15 | ||
| No | 139 | 1.0 | |||
| Diarrhea this pregnancy | 6 | 1.06 (0.47, 2.40) | 0.88 | ||
| No | 158 | 1.0 | |||
| Vaginal bleeding this pregnancy | 8 | 0.82 (0.40, 1.67) | 0.58 | ||
| No | 156 | 1.0 | |||
| Malaria this pregnancy (prior to enrollment) | 47 | 0.80 (0.57, 1.12) | 0.19 | 0.76 (0.53, 1.07) | 0.12 |
| No | 117 | 1.0 | 1.0 | ||
| Presumptive malariac | 1 | 0.50 (0.07, 3.56) | 0.49 | ||
| No | 163 | 1.0 | |||
| Postpartum Malariac | 49 | 2.56 (1.80, 3.65) | <0.0001 | 1.85 (1.25, 2.74) | 0.002 |
| No | 115 | 1.0 | 1.0 | ||
| Chlamydia | 1 | 1.68 (0.23, 12.2) | 0.61 | ||
| No | 163 | 1.0 | |||
| Delivery characteristics | |||||
| Delivery type | |||||
| Spontaneous vaginal delivery | 139 | 1.0 | 1.0 | ||
| Other | 22 | 1.37 (0.88, 2.16) | 0.17 | 1.28 (0.79, 2.08) | 0.31 |
| Blood loss (hemorrhage/transfusion at delivery) | 2 | 3.54 (0.88, 14.3) | 0.08 | 4.29 (0.97, 19.01) | 0.06 |
| No | 162 | 1.0 | 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 4679 observations during follow-up period.
d
Association was significantly nonlinear. P-value corresponds to test of overall significance.