Table 2.
Stratum-specific odds ratios of effect modifiers to the association of gravidity as a multi-level variable and placental malaria, among Ghanaian mothers aged 14–49, estimated by logistic regression fitted with interaction parameters after adjustmenta,b for confounders
| Variable | Category | Gravidity group | % PM (pm/N) | Stratum specific OR (95% CI) | P-value (LRT) |
|---|---|---|---|---|---|
| Stratified by area (N = 1823) | Urban | Multigravidae | 29.5% (59/200) | 1a | 0.07 |
| Secundigravidae | 35.9% (33/92) | 1.04 (0.60–1.81)a | |||
| Primigravidae | 57.7% (52/90) | 2.09 (1.17–3.71)a | |||
| Rural | Multigravidae | 25.8% (240/930) | 1a | ||
| Secundigravidae | 47.8% (119/249) | 1.87 (1.34–2.62)a | |||
| Primigravidae | 68.7% (180/262) | 3.79 (3.61–5.51)a | |||
| Stratified by wealth index (N = 1823) | Higher | Multigravidae | 23.1% (98/424) | 1b | 0.008 |
| Secundigravidae | 32.9% (51/155) | 1.21 (0.79–1.86)b | |||
| Primigravidae | 52.0% (78/150) | 2.14 (1.38–3.35)b | |||
| Lower | Multigravidae | 28.5% (201/706) | 1b | ||
| Secundigravidae | 54.3% (101/186) | 2.05 (1.41–2.98)b | |||
| Primigravidae | 76.2% (154/202) | 4.73 (3.08–7.25)b | |||
| Stratified by ITN use (N = 1782) | Don’t use | Multigravidae | 23.9% (137/573) | 1a | 0.10 |
| Secundigravidae | 43.3% (62/143) | 1.83 (1.20–2.79)a | |||
| Primigravidae | 70.0% (100/145) | 4.22 (2.68–6.67)a | |||
| Use | Multigravidae | 29.6% (158/532) | 1a | ||
| Secundigravidae | 45.6% (87/191) | 1.39 (0.95–2.04)a | |||
| Primigravidae | 62.6% (124/198) | 2.36 (1.54–3.60)a | |||
| Doses of Fansidar (IPTp) (N = 1820) | 0 | Multigravidae | 16.1% (10/62) | 1 | 0.12 |
| Secundigravidae | 38.1% (8/21) | 2.00 (0.63–6.27) | |||
| Primigravidae | 69.2% (9/13) | 7.13 (1.76–28.81) | |||
| 1 | Multigravidae | 26.6% (37/139) | 1 | ||
| Secundigravidae | 38.6% (17/44) | 1.28 (0.61–2.69) | |||
| Primigravidae | 78.4% (40/51) | 5.50 (2.46–12.32) | |||
| 2 | Multigravidae | 25.5% (72/282) | 1 | ||
| Secundigravidae | 48.3% (42/87) | 2.09 (1.22–3.56) | |||
| Primigravidae | 71.0% (64/90) | 4.86 (2.71–8.73) | |||
| 3 | Multigravidae | 27.8% (179/645) | 1 | ||
| Secundigravidae | 45.0% (85/189) | 1.56 (1.07–2.28) | |||
| Primigravidae | 60.4% (119/197) | 2.38 (1.59–3.57) |
LRT Likelihood ratio test
aAdjusted for age, wealth and relationship status
bAdjusted for age relationship