 10. End points evaluation: Prevalence is separately calculated for all participants and for their subgroups according to age, sex, urban or rural residence, BMI and family history of urinary stones, which is expressed as an unadjusted rate with 95 confidence intervals CIs. Difference between the categorical variables is compared using the chi-square test. The association between urinary stone and relevant covariates is calculated using binary logistic regression models. 