Racial and Demographic Variables Are Associated with Accurate 24-hour Urine Collection Completion and Results.

Area of Science:

• Nephrology
• Urology
• Public Health

Background:

• Accurate 24-hour urine collection is crucial for assessing nephrolithiasis risk.
• Demographic factors may influence collection accuracy and urinary stone markers.
• Understanding these disparities is key for effective patient management.

Purpose of the Study:

• To identify demographic predictors of accurate 24-hour urine collection.
• To examine racial differences in lithogenic urine markers among stone-forming patients.
• To inform strategies for improving adherence and personalized risk assessment.

Main Methods:

• Retrospective review of 823 stone-forming patients undergoing 24-hour urine collection (2010-2022).
• Accuracy defined by Mayo Clinic creatinine thresholds.
• Multivariable logistic regression analyzed predictors of accuracy and racial associations with urinary abnormalities.

Main Results:

• 84.3% of patients provided accurate collections.
• Older age (≥55 years) predicted higher accuracy (OR 2.18).
• Male sex and Black race were associated with lower collection accuracy (OR 0.49 and 0.51, respectively).
• Black patients with accurate collections had lower odds of hypercalciuria, hyperphosphaturia, and calcium phosphate supersaturation, but higher odds of hypercitraturia.

Conclusions:

• Younger age, male sex, and Black race are linked to reduced 24-hour urine collection accuracy.
• Targeted patient education is needed to improve adherence.
• Distinct urinary profiles in Black patients suggest a potentially lower risk for calcium-based stones, warranting individualized risk assessment.