Table 3.
Distribution of risk factors, crude and adjusted prevalence ratios for malaria in pregnancy in Mali (crude N = 1,308; adjusted N = 1,258)
| 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 | 339 (25.9) | 11.5 | ref | – | ref | – |
| 1 months | 283 (21.6) | 14.5 | 1.26 (0.84–1.90) | – | 1.19 (0.79–1.79) | – |
| 2 months | 263 (20.1) | 24.3 | 2.12 (1.47–3.04) | – | 1.98 (1.37–2.87) | – |
| 3 months | 168 (12.8) | 21.4 | 1.86 (1.23–2.82) | – | 1.66 (1.09–2.51) | – |
| 4 months | 165 (12.6) | 40.0 | 3.48 (2.45–4.93) | – | 2.81 (1.97–4.01) | – |
| 5 months | 90 (6.9) | 42.2 | 3.67 (2.51–5.38) | – | 3.16 (2.12–4.70) | – |
| Age | 0.002 | 0.004 | ||||
| 25 years+ | 107 (8.2) | 11.2 | ref | – | ref | – |
| 21–24 years | 243 (18.6) | 16.5 | 1.47 (0.80–2.68) | – | 1.57 (0.87–2.84) | – |
| 18–20 years | 606 (46.3) | 25.7 | 2.30 (1.32–3.98) | – | 2.00 (1.16–3.45) | – |
| Under 18 years | 352 (26.9) | 21.6 | 1.93 (1.09–3.40) | – | 1.42 (0.80–2.52) | – |
| Gravidity | < 0.001 | < 0.001 | ||||
| Secundigravid | 512 (39.1) | 14.8 | ref | – | ref | – |
| Primigravid | 796 (60.9) | 26.1 | 1.76 (1.39–2.23) | – | 1.71 (1.32–2.20) | – |
| Gestational age | 0.32 | 0.27 | ||||
| < 20 weeks | 430 (32.9) | 22.8 | ref | – | ref | – |
| 20–24 weeks | 771 (58.9) | 21.9 | 0.96 (0.77–1.20) | – | 0.93 (0.75–1.16) | – |
| 25–30 weeks | 107 (8.2) | 15.9 | 0.70 (0.44–1.11) | – | 0.69 (0.43–1.08) | – |
| Socio-economic status§ | < 0.001 | < 0.001 | ||||
| Least poor | 256 (19.6) | 12.9 | ref | – | ref | – |
| Less poor | 252 (19.3) | 12.3 | 0.95 (0.60–1.51) | – | 0.87 (0.56–1.36) | – |
| Middle | 257 (19.7) | 22.6 | 1.75 (1.18–2.59) | – | 1.41 (0.95–2.10) | – |
| More poor | 259 (19.8) | 26.6 | 2.07 (1.42–3.01) | – | 1.62 (1.11–2.36) | – |
| Most poor | 249 (19.0) | 35.3 | 2.74 (1.91–3.93) | – | 2.01 (1.39–2.90) | – |
| Bed net use previous night§ | 0.19 | 0.26 | ||||
| Yes | 789 (60.3) | 20.5 | ref | – | ref | – |
| No | 496 (37.9) | 23.6 | 1.15 (0.93–1.42) | – | 1.12 (0.92–1.37) | – |
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 = 35 (2.7%); bed net use N = 23 (1.8%).