Table 4.
Distribution of risk factors, crude and adjusted prevalence ratios for malaria in pregnancy in The Gambia (crude N = 1,194; adjusted N = 1,113)
| Variable | Frequency (%) | % Plasmodium falciparum infection | Crude PR* (95% CI) | P value† | Adjusted PR‡ (95% CI) | P value† |
|---|---|---|---|---|---|---|
| Months pregnant in rainy season | < 0.001 | < 0.001 | ||||
| 0 months | 500 (41.9) | 7.8 | ref | – | ref | – |
| 1 months | 201 (16.8) | 6.0 | 0.77 (0.41–1.43) | – | 0.74 (0.39–1.40) | – |
| 2 months | 128 (10.7) | 6.3 | 0.80 (0.38–1.67) | – | 0.82 (0.37–1.86) | – |
| 3 months | 157 (13.2) | 7.0 | 0.90 (0.47–1.71) | – | 1.00 (0.54–1.84) | – |
| 4 months | 208 (17.4) | 16.8 | 2.16 (1.41–3.31) | – | 2.24 (1.45–3.47) | – |
| Age | < 0.001 | 0.05 | ||||
| 25 years+ | 121 (10.1) | 6.6 | ref | – | ref | – |
| 21–24 years | 287 (24.0) | 8.4 | 1.26 (0.58–2.74) | – | 1.03 (0.49–2.19) | – |
| 18–20 years | 569 (47.7) | 6.7 | 1.01 (0.48–2.11) | – | 0.77 (0.38–1.59) | – |
| Under 18 years | 217 (18.2) | 16.1 | 2.44 (1.17–5.09) | – | 1.52 (0.70–3.31) | – |
| Gravidity | 0.03 | 0.06 | ||||
| Secundigravid | 520 (43.5) | 6.7 | ref | – | ref | – |
| Primigravid | 674 (56.5) | 10.4 | 1.54 (1.05–2.28) | – | 1.54 (0.98–2.43) | – |
| Gestational age | 0.001 | < 0.001 | ||||
| < 20 weeks | 394 (33.0) | 12.9 | ref | – | ref | – |
| 20–24 weeks | 652 (54.6) | 7.4 | 0.57 (0.39–0.83) | – | 0.49 (0.33–0.71) | – |
| 25–30 weeks | 148 (12.4) | 4.1 | 0.31 (0.14–0.71) | – | 0.32 (0.14–0.73) | – |
| Socioeconomic status§ | 0.01 | 0.001 | ||||
| Least poor | 228 (19.1) | 4.4 | ref | – | ref | – |
| Less poor | 232 (19.4) | 5.6 | 1.28 (0.57–2.86) | – | 1.31 (0.59–2.91) | – |
| Middle | 222 (18.6) | 9.5 | 2.16 (1.04–4.48) | – | 1.92 (0.93–3.98) | – |
| More poor | 224 (18.8) | 12.1 | 2.75 (1.36–5.55) | – | 2.96 (1.45–6.04) | – |
| Most poor | 211 (17.7) | 12.8 | 2.92 (1.45–5.88) | – | 3.36 (1.66–6.77) | – |
| Bed net use previous night§ | 0.61 | 0.36 | ||||
| Yes | 976 (81.7) | 8.7 | ref | – | ref | – |
| No | 182 (15.2) | 9.9 | 1.14 (0.70–1.84) | – | 1.25 (0.78–2.01) | – |
CI = confidence interval; PR = prevalence ratio; ref = reference.
*
Crude PRs calculated from univariate Poisson regression.
†
P values obtained from Wald’s test. Comparisons restricted to observations without missing data for variables listed.
‡
Adjusted PRs calculated using Poisson regression, adjusting for all other variables listed in the table.
§
Missing values for SES N = 77 (6.4%); bed net use N = 36 (3.0%).