Critical Appraisal informs us that:
Data extrapolated from small study samples are especially prone to error and bias.
Clinical trial researchers have a duty to recruit a sample of volunteers that closely represent the population under study to ensure its results are generalisable.
However:
Minoritised ethnic populations are repeatedly underrepresented in research studies and trials.
Minoritised ethnic populations are disproportionately impacted by various conditions and illnesses.
How Underrepresentation impacts study validity:
External Validity
Sampling bias
Impact to generalisability - participants differ systematically from population under study
Missing racial categories - can not be applied to reader’s population
Internal Validity
Too-small sample sizes of minoritised ethnic populations can impact reliability as it leads to higher variability which may lead to bias
Evidence generated from small sample sizes is especially prone to error (false negatives/positives)