Fig. 3From: Does the low prevalence affect the sample size of interventional clinical trials of rare diseases? An analysis of data from the aggregate analysis of clinicaltrials.govA breakdown of epidemiological data of rare diseases in Orphadata. a Whether or not the rare disease has any prevalence data; b Number of prevalence data entries per rare disease (extracted from literature); c Whether or not the given prevalence value is validated; d The subtype of prevalence information by geographical areaBack to article page