Ethnic differences subjective factors

Very few studies have focused on ethnic African groups. Therefore, very little is known about the molecular basis of ethnic differences in disease incidence and drug response in native Africans. Unfortunately, previous studies in African American subjects cannot be generalized to include native African populations, due to the great heterogeneity of racial ancestry of African American subjects, as well as other factors. 

The test values in a healthy population used to derive a conventional reference interval are subject to the variety of influences including endogenous, exogenous, genetic or ethnic, and laboratory factors discussed above. The statistical approach used to calculate the interval also has considerable influence on the derived reference interval (see Chapter 16). No individual has test results that would span the entire reference interval. Indeed all the results within a healthy individual typically encompass only a small part of most reference intervals. Stratification into more appropriate intervals for subpopulations is sometimes required. The most typical stratifications are based on sex and age. Sinton et al have advocated that separate reference intervals are justified when the difference between the means of the potentially different populations (e.g., men and women or blacks and whites) is greater than 25% of the 95% reference interval of the entire population. An alternative approach to define whether stratification is appropriate is that of Harris and Boyd, which involves calculation of the standard deviations of all of the results from each of the potentially different populations and if the standard deviation of one is more than 1,5 times another stratification is justified. ... 

The influence of ethnic factors on drug responses in clinical trials is important in two contexts. First, the regulatory application should contain data that is generated from subjects whose ethnic mix is in proportion to that in the population where the medicinal product will be used. Second, an applicant may wish that data generated in one country with one ethnic predominance should be used to gain marketing approval in another country where the ethnicity of the population is different. 

In addition to the presence of a consistent sex difference in test scores within each of the four study groups, a significant difference was observed among the groups in terms of the absolute test scores. On the average, the Korean Americans outperformed the Black and White Americans who, in turn, outperformed the Native Japanese (Table 1). All of these means differed significantly from one another, with the exception of the Black and White American ones, which did not differ (Tukey B multiple-comparison post hoc analysis ps < 0.01). Although the reason(s) for these ethnic/cultural differences are not known, differential familiarity with the items is a likely factor, since several of the odors which were not easily identified by the Japanese subjects were unfamiliar to a number of... 

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