Factors Associated With Compliance With 24-Hour Urine Collection

To identify how demographic factors, stone-associated medical comorbidities, and treatment predict compliance with 24-hour urine collection.

A retrospective medical record review of patients treated for urolithiasis between August 2014 and March 2017 was performed. Patient demographics, medical characteristics, stone factors, type of treatment, and compliance data were included for patients requested to submit a collection. Variables that were statistically significant on bivariate analysis were then used to formulate a model predicting submission of a 24-hour urine sample.

Of the 303 patients who met inclusion criteria, 183 (60.4%) submitted an initial 24-hour urine collection. On bivariate analysis, patients older than 50 were more likely to submit a 24-hour urine collection (71.4% vs 51.5%; P <.001), patients with a metabolic predisposition for stones were more likely to submit a 24-hour urine collection (70.6% vs 53.1%; P <.003), and patients who did not have surgery were more likely to submit a 24-hour urine collection (97.9% vs 53.5%; P <.001). Our 3-variable prediction model found that not undergoing surgery was a strong predictor of 24-hour urine collection.

We suspect that patients perceive surgery as a more definitive treatment for kidney stones than conservative management. Patient education on the natural history and role of metabolic management in the prevention of nephrolithiasis is essential in improving compliance with 24-hour urine collection.