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

Katherine Chan, E. A. Moser, Benjamin Whittam, R. Misseri, M. P. Cain, Amy Krambeck, A. Schwaderer

Research output: Contribution to journalArticle

Abstract

Introduction: 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. Objective: The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. Study design: A retrospective analysis of all children (<18 years of age) with renal and/or ureteral calculi evaluated at the study tertiary care pediatric center from 2005 to 2015 was performed. Those who had at least one 24-h urinary metabolic profile after a clinical visit for kidney and/or ureteral stones were included; children with bladder stones were excluded. Adequate collections had a urine creatinine of 10–15 mg/kg/24 h. A bivariate analysis of potential factors associated with inadequate collection of the initial urinary metabolic profile, including child demographics, parental socio-economic factors, history of stone surgery, and weekday vs. weekend urine collection, was performed. A mixed-effects logistic regression, controlling for correlation of specimens from the same patient, was also performed to determine whether an initial inadequate collection predicted a subsequent inadequate collection. Results: Of 367 patients, 80 had an adequate collection (21.9%): median age, 13 years (interquartile range, 8–16); 61.1% female; 93.5% white; 19.5% obese; and 13.0% overweight. No parental or child factors were associated with inadequate collection (Summary Table). Of inadequate collections, more than 80% were over collections. In the 175 patients with more than one 24-h urinary specimen collection, the effect of an initial inadequate collection on subsequent inadequate collections was not significant after controlling for the correlation of samples from the same patient (p = 0.8). Discussion: Any parental or child factors associated with the collection of inadequate 24-h urine specimens in children were not found. An initial inadequate collection does not predict subsequent inadequate collections. It was surprising that >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. Conclusion: Inadequate collections are very common, and the risk factors for them are unclear. A repeat collection would be suggested if the first is inadequate. Further studies must be planned to explore barriers to accurate specimen collection using qualitative research methodology.

Original languageEnglish (US)
JournalJournal of Pediatric Urology
DOIs
StateAccepted/In press - Jan 1 2018

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Urine
Specimen Handling
Creatinine
Qualitative Research
Vitamin D
Body Mass Index
Research Design
Pediatrics
Population

Keywords

  • Cost–benefit analysis
  • Healthcare costs
  • Pediatrics
  • Urolithiasis

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Urology

Cite this

@article{8503580e7d4547deb80c30aad83f6a3d,
title = "Initial collection of an inadequate 24-hour urine sample in children does not predict subsequent inadequate collections",
abstract = "Introduction: 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. Objective: The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. Study design: A retrospective analysis of all children (<18 years of age) with renal and/or ureteral calculi evaluated at the study tertiary care pediatric center from 2005 to 2015 was performed. Those who had at least one 24-h urinary metabolic profile after a clinical visit for kidney and/or ureteral stones were included; children with bladder stones were excluded. Adequate collections had a urine creatinine of 10–15 mg/kg/24 h. A bivariate analysis of potential factors associated with inadequate collection of the initial urinary metabolic profile, including child demographics, parental socio-economic factors, history of stone surgery, and weekday vs. weekend urine collection, was performed. A mixed-effects logistic regression, controlling for correlation of specimens from the same patient, was also performed to determine whether an initial inadequate collection predicted a subsequent inadequate collection. Results: Of 367 patients, 80 had an adequate collection (21.9{\%}): median age, 13 years (interquartile range, 8–16); 61.1{\%} female; 93.5{\%} white; 19.5{\%} obese; and 13.0{\%} overweight. No parental or child factors were associated with inadequate collection (Summary Table). Of inadequate collections, more than 80{\%} were over collections. In the 175 patients with more than one 24-h urinary specimen collection, the effect of an initial inadequate collection on subsequent inadequate collections was not significant after controlling for the correlation of samples from the same patient (p = 0.8). Discussion: Any parental or child factors associated with the collection of inadequate 24-h urine specimens in children were not found. An initial inadequate collection does not predict subsequent inadequate collections. It was surprising that >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. Conclusion: Inadequate collections are very common, and the risk factors for them are unclear. A repeat collection would be suggested if the first is inadequate. Further studies must be planned to explore barriers to accurate specimen collection using qualitative research methodology.",
keywords = "Cost–benefit analysis, Healthcare costs, Pediatrics, Urolithiasis",
author = "Katherine Chan and Moser, {E. A.} and Benjamin Whittam and R. Misseri and Cain, {M. P.} and Amy Krambeck and A. Schwaderer",
year = "2018",
month = "1",
day = "1",
doi = "10.1016/j.jpurol.2018.10.019",
language = "English (US)",
journal = "Journal of Pediatric Urology",
issn = "1477-5131",
publisher = "Elsevier BV",

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TY - JOUR

T1 - Initial collection of an inadequate 24-hour urine sample in children does not predict subsequent inadequate collections

AU - Chan, Katherine

AU - Moser, E. A.

AU - Whittam, Benjamin

AU - Misseri, R.

AU - Cain, M. P.

AU - Krambeck, Amy

AU - Schwaderer, A.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Introduction: 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. Objective: The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. Study design: A retrospective analysis of all children (<18 years of age) with renal and/or ureteral calculi evaluated at the study tertiary care pediatric center from 2005 to 2015 was performed. Those who had at least one 24-h urinary metabolic profile after a clinical visit for kidney and/or ureteral stones were included; children with bladder stones were excluded. Adequate collections had a urine creatinine of 10–15 mg/kg/24 h. A bivariate analysis of potential factors associated with inadequate collection of the initial urinary metabolic profile, including child demographics, parental socio-economic factors, history of stone surgery, and weekday vs. weekend urine collection, was performed. A mixed-effects logistic regression, controlling for correlation of specimens from the same patient, was also performed to determine whether an initial inadequate collection predicted a subsequent inadequate collection. Results: Of 367 patients, 80 had an adequate collection (21.9%): median age, 13 years (interquartile range, 8–16); 61.1% female; 93.5% white; 19.5% obese; and 13.0% overweight. No parental or child factors were associated with inadequate collection (Summary Table). Of inadequate collections, more than 80% were over collections. In the 175 patients with more than one 24-h urinary specimen collection, the effect of an initial inadequate collection on subsequent inadequate collections was not significant after controlling for the correlation of samples from the same patient (p = 0.8). Discussion: Any parental or child factors associated with the collection of inadequate 24-h urine specimens in children were not found. An initial inadequate collection does not predict subsequent inadequate collections. It was surprising that >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. Conclusion: Inadequate collections are very common, and the risk factors for them are unclear. A repeat collection would be suggested if the first is inadequate. Further studies must be planned to explore barriers to accurate specimen collection using qualitative research methodology.

AB - Introduction: 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. Objective: The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. Study design: A retrospective analysis of all children (<18 years of age) with renal and/or ureteral calculi evaluated at the study tertiary care pediatric center from 2005 to 2015 was performed. Those who had at least one 24-h urinary metabolic profile after a clinical visit for kidney and/or ureteral stones were included; children with bladder stones were excluded. Adequate collections had a urine creatinine of 10–15 mg/kg/24 h. A bivariate analysis of potential factors associated with inadequate collection of the initial urinary metabolic profile, including child demographics, parental socio-economic factors, history of stone surgery, and weekday vs. weekend urine collection, was performed. A mixed-effects logistic regression, controlling for correlation of specimens from the same patient, was also performed to determine whether an initial inadequate collection predicted a subsequent inadequate collection. Results: Of 367 patients, 80 had an adequate collection (21.9%): median age, 13 years (interquartile range, 8–16); 61.1% female; 93.5% white; 19.5% obese; and 13.0% overweight. No parental or child factors were associated with inadequate collection (Summary Table). Of inadequate collections, more than 80% were over collections. In the 175 patients with more than one 24-h urinary specimen collection, the effect of an initial inadequate collection on subsequent inadequate collections was not significant after controlling for the correlation of samples from the same patient (p = 0.8). Discussion: Any parental or child factors associated with the collection of inadequate 24-h urine specimens in children were not found. An initial inadequate collection does not predict subsequent inadequate collections. It was surprising that >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. Conclusion: Inadequate collections are very common, and the risk factors for them are unclear. A repeat collection would be suggested if the first is inadequate. Further studies must be planned to explore barriers to accurate specimen collection using qualitative research methodology.

KW - Cost–benefit analysis

KW - Healthcare costs

KW - Pediatrics

KW - Urolithiasis

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