Table 3.
Results of linear regression analysis investigating the effect of age, gender and malaria status as determined by microscopyb on logged antibody levels to AMA1, MSP1, MSP2, NANP and IgE
| Factor | Anti-AMA1 levels (n = 10,137) | Anti-MSP1 levels (n = 10,200) | Anti-MSP2 levels (n = 10,283) | Anti-NANP levels (n = 5,531)a | Total IgE levels (n = 4,961)a | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Beta (95 % CI) | p-value | Beta (95 % CI) | p-value | Beta (95 % CI) | p-value | Beta (95 % CI) | p-value | Beta (95 % CI) | p-value | |
| Age (years) | ||||||||||
| <1 | 0 | 0 | 0 | 0 | 0 | |||||
| 1–2 | 0.04 (−0.09 to 0.17) | 0.576 | −0.10 (−0.22 to 0.01) | 0.083 | 0.16 (0.05 to 0.28) | 0.006 | 0.30 (0.04 to 0.55) | 0.023 | 0.09 (−0.17 to 0.35) | 0.508 |
| 2–5 | 0.25 (0.15 to 0.35) | <0.001 | 0.08 (−0.01 to 0.17) | 0.087 | 0.29 (0.20 to 0.38) | <0.001 | 0.50 (0.30 to 0.71) | <0.001 | 0.09 (−0.12 to 0.30) | 0.398 |
| 5–15 | 0.57 (0.47 to 0.67) | <0.001 | 0.37 (0.28 to 0.45) | <0.001 | 0.61 (0.52 to 0.69) | <0.001 | 0.87 (0.67 to 1.07) | <0.001 | 0.19 (−0.01 to 0.40) | 0.066 |
| 15–30 | 0.55 (0.46 to 0.65) | <0.001 | 0.65 (0.57 to 0.74) | <0.001 | 0.72 (0.63 to 0.81) | <0.001 | 1.43 (1.23 to 1.63) | <0.001 | 0.22 (0.02 to 0.43) | 0.034 |
| >30 | 0.53 (0.43 to 0.63) | <0.001 | 0.81 (0.72 to 0.90) | <0.001 | 0.72 (0.63 to 0.81) | <0.001 | 1.61 (1.40 to 1.81) | <0.001 | 0.14 (−0.07 to 0.35) | 0.179 |
| Gender | ||||||||||
| Female | 0 | 0 | 0 | 0 | 0 | |||||
| Male | −0.03 (−0.07 to 0) | 0.058 | −0.08 (−0.11 to −0.05) | <0.001 | −0.05 (−0.07 to −0.02) | 0.002 | −0.07 (−0.11 to −0.03) | 0.004 | 0.12 (0.09 to 0.16) | <0.001 |
| Microscopy result | ||||||||||
| Negative | 0 | 0 | 0 | 0 | 0 | |||||
| Positive | 0.17 (0.13 to 0.22) | <0.001 | 0.15 (0.11 to 0.19) | <0.001 | 0.21 (0.18 to 0.25) | <0.001 | −0.03 (−0.08 to −0.02) | 0.263 | 0.06 (0.01 to 0.11) | 0.021 |
Results shown as betas, which indicate the direction of effect of the clinical covariate on antibody levels. Beta < 0 indicate a decrease in antibody levels and beta > 0 indicate an increase in antibody levels. 95 % confidence intervals that do not span 0 indicate an effect that is significant at p = 0.05.
NB: CI confidence interval; results significant at 0.05 level are highlighted in italics.
aData not available for Tanzania (Moshi).
b Also adjusted for village (>20), ethnicity (>20), sample month (>20) and study; results not shown but ANOVA p-values were <0.001 for all antibodies.