DEMOGRAPHIC AND GEOGRAPHIC VARIABILITY OF KIDNEY-STONES IN THE UNITED-STATES

To characterize demographic and regional variation in kidney stone pre valence in the U.S., we studied two nationwide cross-sectional surveys that included data on self-reported, physician-diagnosed kidney stone s, supplementing published data on hospitalizations for stones. The la rger study, Cancer Prevention Study II (CPS II), included 1,185,124 me n and women, age greater than or equal to 30, recruited nationally in 1982, and provides state-specific prevalence estimates. The National H ealth and Nutrition Examination Survey (NHANES II) was a national prob ability sample of 25,286 U.S. adults interviewed between 1976 and 1980 . Kidney stone prevalence increased with age until age 70, then declin ed and was higher in men than women and in whites than blacks. Prevale nce among Hispanic and Asian men was intermediate between that of whit es and blacks. There was a strong, statistically significant regional variability in stone prevalence among U.S. whites. The age-adjusted pr evalence increased from north to south, and from west to east. The con trast in state-specific prevalence was greatest between men in North C arolina (prevalence = 14.9; 95% confidence interval = 14.2 to 15.7) an d North Dakota (5.6; 4.7 to 6.4), and between women in South Carolina (6.4; 5.8 to 6.9) and South Dakota (2.4; 1.9 to 2.9). The marked varia tions in kidney stone prevalence by age, gender, race, and geographic location may provide clues to their etiology and prevention.