Initial collection of an inadequate 24-hour urine sample in children does not predict subsequent inadequate collections

• Published in: Journal of pediatric urology 2019-02, Vol.15 (1), p.74.e1-74.e7
• Main Authors: Chan, K.H., Moser, E.A., Whittam, B.M., Misseri, R., Cain, M.P., Krambeck, A., Schwaderer, A.
• Format: Article
• Language: English
• Subjects: Adolescent; Child; Cost–benefit analysis; Creatinine - urine; Female; Healthcare costs; Humans; Kidney Calculi - urine; Male; Monitoring, Physiologic - methods; Pediatrics; Predictive Value of Tests; Retrospective Studies; Risk Factors; Time Factors; Ureteral Calculi - urine; Urine Specimen Collection - methods; Urine Specimen Collection - standards; Urolithiasis
• ISSN: 1477-5131; 1873-4898
• DOI: 10.1016/j.jpurol.2018.10.019

Approximately half of adult stone formers submit specimens that are either under or over collections as determined by 24-h creatinine/kg. Previously identified predictors of inadequate collection in adults include female sex, older age, higher body mass index (BMI), vitamin D supplementation, and weekday collection. The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. A retrospective analysis of all children (80% of the inadequate collections were over collections rather than under collections. Possible explanations are that children collected urine samples for longer than the 24-h period or that stone-forming children produce more creatinine per 24-h period than healthy children due to hyperfiltration. Inadequate collections are