Moreover, the differences between the different studies might also be related to the size and characteristics of the patient cohorts analyzed in the different studies.
The ECV data of normal volunteers do not significantly differ between the different studies, being in the range of 24 28 % [56, 58, 59, 60, 61, 62]; see Table 2.
The major differences between the different studies lie in the exact classification algorithm, even though some popular classifiers (K-nearest neighbour, Gaussian multivariate, neural network) are often used as a basis.
Despite of much effort to study motivations to become a teacher across countries, there is a lack of comparative evidences, caused by the variety of instruments, which differ substantially between the different studies.
The heterogeneity of the observed differences in reported results between the different studies (Table 2) may be explained in part by the differences in the patient populations.
14 However, other authors have not found RGC death or alterations of the axonal transport in aged RCS rats, 15 but these studies have used younger animals than we used and thus it is possible that the discrepancies between the different studies are due to the differences in the methodology employed.
Possible other explanations for the difference in recurrences rates between the different studies are heterogeneity of data collection and selection bias, for instance excluding women with a stage 4 uterine descent.
The heterogeneity between the different studies results in large differences in retention rates and Kaplan-Meier curves of anti-TNF therapy survival.
The large variation seen in predictors between the different studies is probably related to the differences in the ethnic origin of the populations studied, the differences in sample size and the different screening strategies used for GDM.
It has been reported that there are large variations in the levels of CSF A β and Tau between the different studies, 50 which could be caused by the differences in analytical procedures and the analytical kits.
The results indicate that the body dimensions of Mexican children from this study are different from those of American, Cuban, and other Mexican children, probably due to ethnic differences and the time lapse between the different studies.
