Table 2.
Distribution of risk factors, crude and adjusted prevalence ratios for malaria in pregnancy in Burkina Faso (crude N = 1,434; adjusted N = 1,330)
| 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 | 262 (18.3) | 34.4 | ref | – | ref | – |
| 1 months | 287 (20.0) | 27.9 | 0.81 (0.63–1.04) | – | 0.87 (0.68–1.13) | – |
| 2 months | 272 (19.0) | 43.8 | 1.27 (1.03–1.58) | – | 1.38 (1.11–1.71) | – |
| 3 months | 207 (14.4) | 44.0 | 1.28 (1.02–1.61) | – | 1.34 (1.06–1.68) | – |
| 4 months | 205 (14.3) | 53.7 | 1.56 (1.27–1.93) | – | 1.70 (1.38–2.10) | – |
| 5 months | 180 (12.6) | 56.7 | 1.65 (1.34–2.04) | – | 1.85 (1.50–2.29) | – |
| Age | < 0.001 | < 0.001 | ||||
| 25 years+ | 131 (9.1) | 23.7 | ref | – | ref | – |
| 21–24 years | 433 (30.2) | 29.1 | 1.23 (0.87–1.73) | – | 1.25 (0.88–1.76) | – |
| 18–20 years | 855 (59.6) | 51.0 | 2.15 (1.57–2.95) | – | 1.81 (1.30–2.53) | – |
| Under 18 years | 15 (1.1) | 60.0 | 2.54 (1.51–4.24) | – | 1.67 (0.73–3.82) | – |
| Gravidity§ | < 0.001 | < 0.001 | ||||
| Secundigravid | 750 (52.3) | 30.4 | ref | – | ref | – |
| Primigravid | 663 (46.2) | 54.9 | 1.81 (1.59–2.05) | – | 1.43 (1.24–1.65) | – |
| Gestational age§ | 0.003 | 0.002 | ||||
| < 20 weeks | 489 (34.1) | 47.0 | ref | – | ref | – |
| 20–24 weeks | 750 (52.3) | 40.8 | 0.87 (0.76–0.99) | – | 0.85 (0.75–0.96) | – |
| 25–30 weeks | 174 (12.1) | 32.2 | 0.68 (0.54–0.87) | – | 0.69 (0.55–0.88) | – |
| Socio-economic status§ | 0.35 | 0.16 | ||||
| Least poor | 280 (19.5) | 41.8 | ref | – | ref | – |
| Less poor | 264 (18.4) | 41.7 | 1.00 (0.82–1.22) | – | 0.92 (0.76–1.11) | – |
| Middle | 281 (19.6) | 45.2 | 1.08 (0.90–1.31) | – | 1.02 (0.85–1.21) | – |
| More poor | 266 (18.6) | 45.1 | 1.08 (0.89–1.31) | – | 1.03 (0.86–1.24) | – |
| Most poor | 270 (18.8) | 37.4 | 0.90 (0.73–1.10) | – | 0.83 (0.68–1.01) | – |
| Bed net use previous night§ | 0.06 | 0.10 | ||||
| Yes | 769 (53.6) | 39.9 | ref | – | ref | – |
| No | 651 (45.4) | 44.9 | 1.12 (0.99–1.27) | – | 1.11 (0.98–1.25) | – |
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 season N = 21 (1.5%); gravidity N = 21 (1.5%); gestational age (1.5%); SES N = 73 (5.1%); bed net use N = 14 (1.0%).