Perceptions of dietary factors promoting and preventing nephrolithiasis: a cross-sectional survey

Objective: To assess knowledge of both promoting and preventive dietary factors on nephrolithiasis in a diverse patient population. Precipitating factors of kidney stone disease include diet, lifestyle, socioeconomic status, and race/ethnicity. However, patient awareness of these influences is poorly described.

Materials and methods: A 24-question survey, assessing intake-related risk factors for stone disease, was administered prospectively to 1018 patients. Responses were summarized with frequency and percent. Statistical comparisons were made using a propensity scoring method in order to account for potential confounding variables. Propensity scores were stratified into quintiles. Further analysis with multiple imputation was performed to account for any missing data in the survey. The results of the propensity-adjusted log-binomial regression model are presented as prevalence ratios (PRs) and 95% confidence intervals (CIs).

Results: Respondents demonstrated limited knowledge of nutrient factors that influence stone development. However, most study participants (70.3%) reported a willingness to make lifestyle changes aimed at lowering their risk for stone disease. Respondents reporting previous nephrolithiasis education were less likely to report that diet had no effect on kidney stone formation (PR = 0.795, 95% CI 0.65, 0.96, p = 0.01) The type of physician who counseled the respondent had no association with patient knowledge for stone disease (PR = 0.83, 95% CI 0.63, 1.10, p = 0.2).

Conclusions: Knowledge of diet-related risk factors for nephrolithiasis is limited among this population. Respondents who received prior education appeared to maintain the knowledge of dietary risk for nephrolithiasis. Participants also expressed a willingness to make requisite dietary changes if that information is provided. Given that most stone formers experience a recurrence, these findings highlight the need for more comprehensive patient education strategies on the modifiable risk factors for nephrolithiasis.