Race, ethnicity and urolithiasis: a critical review.

Using combinations of the key words urolithiasis, kidney stones, race, ethnicity, population group in Google Scholar and Pubmed, a literature search identified 40 articles. Of these, 33 satisfied the principal inclusion criterion of studies involving comparison of at least two groups in which there is a perceived difference in stone occurrence. Studies were classified as "weak" (no attempt to account for inter-racial or inter-ethnic group differences in stone occurrence), "soft" (speculative explanations reached by default) or "hard" (explanations based on empirically measured lithogenic risk factors). Only 12 studies (36 %) fell into the latter category. Among these, a wide diversity of lithogenic factors was invoked to explain inter-group differences in stone rates. Traditional urinary physicochemical risk factors do not convincingly account for these differences. Studies have failed to yield a consolidated and unifying theory which compellingly explains racial and ethnic differences in urolithiasis.