Table 3.
Univariate and multivariate associations with microscopically visible, polyclonal P. falciparum infections
| Parameter | No. | Mean MOI (median, range) | P | Multivariate analysisa | Polyclonal infections (%) | OR (95%CI) | P | Multivariate analysisb | |||
|---|---|---|---|---|---|---|---|---|---|---|---|
| b | SE | P | aOR (95%CI) | P | |||||||
| Previous IPTi-SP | |||||||||||
| No | 142 | 2.38 (2, 1-6) | 72.5 | 1 | 1 | ||||||
| Yes | 135 | 2.42 (2, 1-5) | 0.78 | -0.05 | 0.22 | 0.82 | 74.8 | 1.12 (0.64-1.99) | 0.67 | 0.93 (0.52-1.64) | 0.79 |
| Cohort | |||||||||||
| Tamale | 104 | 2.57 (2, 1-5) | 78.8 | 1 | 1 | ||||||
| Afigya Sekyere | 173 | 2.30 (2, 1-6) | 0.07 | -0.67 | 0.26 | 0.01 | 70.5 | 0.64 (0.35-1.18) | 0.13 | 0.53 (0.28-1.03) | 0.06 |
| Current malaria episode | |||||||||||
| No | 114 | 2.21 (2, 1-6) | 64.0 | 1 | 1 | ||||||
| Yes | 163 | 2.53 (2, 1-5) | 0.01 | 0.55 | 0.24 | 0.02 | 80.4 | 2.30 (1.29-4.11) | 0.002 | 2.35 (1.27-4.32) | 0.006 |
| Parasite density (/μL) | |||||||||||
| Log10 | 277 | n.a. | 0.049 | 0.24 | 0.13 | 0.07 | n.a. | 1.48 (1.08-2.03) | 0.01 | 1.38 (0.99-1.94) | 0.06 |
| Prior malaria episodes | |||||||||||
| None | 72 | 2.50 (2, 1-5) | 81.9 | 1 | 1 | ||||||
| Any | 205 | 2.37 (2, 1-6) | 0.30 | -0.19 | 0.26 | 0.46 | 70.7 | 0.53 (0.26-1.09) | 0.06 | 0.51 (0.25-1.05)c, d | 0.07 |
| Season | |||||||||||
| Dry season | 92 | 2.49 (2, 1-5) | 79.3 | 1 | 1 | ||||||
| Rainy season | 185 | 2.36 (2, 1-6) | 0.32 | -0.77 | 0.27 | 0.004 | 70.8 | 1.58 (0.84-3.01) | 0.13 | 0.36 (0.18-0.72) | 0.004 |
a, multivariate results are derived from non-parametric ordinal regression analysis including all listed parameters. b, adjusted odds ratios (aORs) are derived from logistic regression models including all other listed parameters; SE, standard error; OR, odds ratio; 95%CI, 95% confidence interval; n.a., not applicable; c, exchanging with number of previous malaria episodes (0-7): aOR, 0.98, 95%CI, 0.81-1.19; P = 0.84. d, The proportion of polyclonal infections according to arbitrarily set time periods from last previous episode was: <8 weeks (n = 65), 76.9%; 8-16 weeks (n = 62), 72.6%; >16 weeks (n = 78), 64.1%. Exchanging this graded parameter with prior episodes per se yielded respective aORs (95%CIs) of 0.73 (0.30-1.78), 0.72 (0.29-1.76), and 0.32 (0.14-0.73).