Recent attention directed to ‘inclusion’ policies to determine sex differences began in late 1980’s because of concern that clinical research on conditions that affect both women & men was being conducted primarily in a homogeneous white male population, but results applied in medical practice to both men and women of all races.
The aim has to be to insure that scientific norms for health, disease, treatments and other medical interventions are applicable to all populations (men & women, diverse racial/ethnic groups), based upon scientific evidence established by studying those populations; i.e., are there biological or other differences in effect based upon sex or race/ethnicity?
The term "valid analysis" means an unbiased assessment. Such an assessment will, on average, yield the correct estimate of the difference in outcomes between two groups of subjects. Valid analysis can and should be conducted for both small and large studies. A valid analysis does not need to have a high statistical power for detecting a stated effect.