A Comparative Analysis of Socioeconomic Deprivation Indices and Urinary Risk Factors in Patients with Nephrolithiasis

To compare the Area Deprivation Index (ADI) and Distressed Communities Index (DCI) in identifying socioeconomic disparities in 24-hour urine (24hU) parameters and stone composition among patients undergoing percutaneous nephrolithotomy (PCNL).

Retrospectively, 1859 adults who underwent PCNL between 2017 and 2022 and completed at least one 24hU collection were included. Patients were assigned ADI and DCI percentiles based on residential location. Demographics, urine chemistries, categorical urine abnormalities, and stone composition were compared across index quartiles. Multivariable logistic regression adjusted for age, sex, race, and body mass index assessed associations between socioeconomic quartiles and urinary abnormalities or stone type. Predictive performance of ADI- and DCI-based models was compared using discrimination and non-nested model testing.

Greater socioeconomic deprivation was associated with younger age, higher body mass index, and lower completion of metabolic testing. Higher ADI quartiles were associated with lower urine volume, lower urinary potassium, increased odds of low urine volume, and hypocitraturia. DCI quartiles demonstrated similar associations with urine volume but were additionally associated with urinary oxalate and uric acid, while showing no significant association with hypocitraturia. ADI quartile 4 was associated with lower odds of calcium oxalate stones and higher odds of struvite and calcium phosphate stones, whereas DCI showed weaker associations with stone composition. For outcomes significantly associated with both indices, neither demonstrated superior predictive performance.

ADI and DCI identify complementary socioeconomic disparities in nephrolithiasis. ADI was more strongly associated with categorical urine abnormalities and stone composition, whereas DCI correlated more closely with continuous urine chemistries.