The different methodologies of these epidemiological surveys are likely to explain a part of the variation in prevalence.
We aimed to quantify the variation in prevalence of childhood myopia over time, accounting for demographic and study design factors.
There may be seasonal variation in prevalence in this area, though no significant differences were observed between the data collected in December and March.
Decades of psychiatric epidemiology have shown a wide variation in prevalence rates, but a consistent relationship between psychiatric disorder and sociodemographic variables.
The ability to relapse from long-lasting liver-stages restricts the seasonal variation in prevalence of P. vivax infections.
It was found that there was a regional variation in prevalence rates for depression among the three cities.
HCV infection varied substantially between ethnic groups which could be clustered into low-prevalence and high-prevalence categories, with a 3-fold variation in prevalence.
The variation in prevalence observed between villages was greater in Dedza than in Mangochi when either microscopy (Dedza: range 2.2 58.4%, standard deviation (S.D).
However, between-village variation in prevalence (after accounting for demographic and geo-climatic factors) was observed only in Dedza region, with villages in Mangochi being far more homogeneous.
The large variation in prevalence may have several explanations.
Such methodological differences may also contribute to variation in prevalence estimates across different studies.
