This suggests that both the population hemoglobin mean (popHb) and anemia prevalence (AP), following correction for altitude, correlate directly with the variations of malaria transmission intensity and may thus be useful as measures of malaria endemicity.
For such a multistage cluster sampling method, a sample size of 1,530 students was required to have a precision of 0.05 on the estimated prevalence, with a correction for clustering effect of 2.1 and with a prior prevalence of 12% in wealthy districts and 2% in less wealthy districts [ 9].
After refraction and spectacle correction, the prevalence of visual impairment and blindness decreased to 6.7% and 0.75%, respectively, suggesting that refractive error is the major correctable cause of visual impairment and blindness in this population.
After best correction the prevalence of blindness was 0.43%.
We calculated prevalence after applying a correction factor for 100% collection coverage.
After refractive correction, the prevalence of mild, moderate and severe visual impairment was significantly decreased(mild:χ=150.13, P<0.001, moderate:χ=119.46, P<0.001, severe:χ=10.69, P=0.001), while the prevalence of blindness was not significantly changed (χ=1.82, P=0.277).
For each of these objectives, we recommend that future studies link phylogenetic analysis with prevalence data, allowing for correction of known biases and providing crucial complementary epidemiologic evidence for migration and persistence.
In previous analyses with data from KiGGS baseline, which provide both self-reported and measured values, correction of prevalence rates for weight status derived from self-reports with Kurth and Ellert's [ 10] formula showed satisfying results [ 13].
With higher HIV prevalence, the impact of corrections for misclassifications would have been higher and may have reduced the precision of the estimations [ 12, 13].
