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The urinary normetanephrine to creatinine ratio (uNMN/Cr) and urinary metanephrine to creatinine ratio (uMN/Cr) are commonly evaluated for the diagnosis of pheochromocytomas (PCC) in dogs. This study aimed to establish reference intervals for uNMN/Cr and uMN/Cr in 56 healthy dogs in Japan and to investigate the effect of urine collection methods on these measurements in 15 non-PCC dogs. The upper limits of reference intervals for uNMN/Cr and uMN/Cr were 124.4 nmol/mmol (90% confidence interval [CI] 107.7-137.0) and 121.1 nmol/mmol (90% CI 102.8-145.1), respectively. Both uNMN/Cr and uMN/Cr were significantly higher when urine was collected in the hospital compared to at home. Several factors, including the method of urine collection, should be considered when utilizing these reference intervals.

Introduction: Long-term sodium balance studies show that sodium can be temporarily stored and released in tissues, mediated by circaseptan rhythms of aldosterone and cortisol. This complicates the reliability of a single 24-h urine collection to estimate individual sodium intake. We investigated whether repeated timed urine collection with and without correction for plasma aldosterone is a more accurate alternative for estimating daily sodium intake., Methods: We conducted a post hoc analysis of a metabolic ward study in which 16 healthy male adults consumed a diet with a fixed sodium content (50 or 200 mmol/day) for 7 days. Each day, urine was collected in 4 intervals (7:00-13:00 h, 13:00-19:00 h, 19:00-23:00 h, and 23:00-07:00 h). Plasma aldosterone was measured at 6:30 h, 12:30 h, and 18:30 h. Sodium intakes were estimated by various formulas using 3 timed urines of day 5-7., Results: During a 200-mmol daily sodium intake, sodium intake estimates based on three repeated timed urine samples and the Toft equation differed 10 [IQR: 3-14], 8 [6-19], 36 [16-49], and 20 [10-43] mmol from the actual intake for intervals 7:00-13:00 h, 13:00-19:00 h, 19:00-23:00 h, 23:00-7:00 h, respectively. These measurements did not significantly differ from a single 24-h urine (20 [12-55] mmol). During a 50-mmol daily sodium intake, repeated timed urine collection performed worse than a single 24-h urine collection. On both diets, correction for plasma aldosterone increased accuracy and sodium intake estimates were significantly more accurate than a single 24-h urine., Conclusion: In a controlled environment, repeated timed urine collection corrected for plasma aldosterone is more accurate than a single 24-h urine collection., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Purpose: Microscopic hematuria is one of the most common office consults for urologists. While revised guidelines have risk-stratified patients to reduce unnecessary screening, they do not provide guidance concerning specimen quality. We sought to define "properly collected" specimens using catheterized urine samples as a reference to improve the utility of hematuria screening in women., Materials and Methods: We prospectively acquired same-visit voided and catheterized urine samples from 46 women referred for microscopic hematuria from September 2016 to March 2020. Characteristics of pre-referral urinalysis were compared to the matched specimens. True microscopic hematuria was defined as ≥3 red blood cells per high power field on catheterization., Results: Catheterized urinalyses had significantly fewer red blood and squamous epithelial cells in comparison to both referral urinalyses (p=0.006, p=0.001, respectively) and same-day void urinalyses (p=0.02, p=0.04, respectively). As no catheterized sample had >2 squamous epithelial cells, we applied this squamous epithelial cell threshold to referral urinalyses for analysis. Addition of this criterion for "properly collected specimen" increased the positive predictive value of referral urinalyses from 46.1% to 68.8% for true microscopic hematuria. Fewer than 2 squamous epithelial cells with elevated RBC was a significant predictor for true microscopic hematuria (p=0.003)., Conclusions: Voided specimens in the urology clinic had significantly lower red blood cells than referral samples, indicating improved collection technique may reduce false positive urinalyses. Matched collection suggested that repeat collection by catheterization in women who present with >2 squamous epithelial cells per high power field on referral urinalysis may prevent unnecessary future work-up.

Purpose: The commonly used 24-hour collection technique has been the mainstay of diagnosis for supersaturation but has some certain limitations. Hence, superiority of multiple short urine collections as a new alternative in precipitation risk assessment was assessed compared to the standard 24-hour urine collection among healthy subjects., Materials and Methods: Individual urine samples of 26 healthy subjects were acquired every 2 to 3 hours throughout the 24 hours. Urine samples were obtained and the time and volume of each sample were recorded. Urinary constituents involved in precipitation including, sodium-potassium, chloride, calcium, phosphate, citrate, magnesium, urea, creatinine and pH were measured. A simulated 24-hour collection was recalculated by the totalling of all shorter urine collections volume and urinary constituents excretions throughout the day., Results: Urine pH, urine creatinine and precipitation rate had a significantly lower values in 24-hours urine collection compared to one individual value of multiple urine collections by -0.769 (P < .0001), -7.305 (P < .0001), and - 12.838 (P < .0001), respectively. However, calcium (2.697, P < .0001), citrate (3.54, P < .0001), total phosphate (19.961, P < .0001) and total creatinine (9.579, P < .0001) had statistically significantly higher values in the 24-hours urine collection compared to individual value of multiple urine collections., Conclusion: Based on the results, individual analysis of multiple shorter urine collections throughout the day improves the ability of identifying supersaturation points, precipitation risk zones and may potentially improve risk assessment compared to the 24-hour urine collection method., (© 2020 Asian Pacific Society of Nephrology.)

Globally, average dietary sodium intake is double the recommended amount, whereas potassium is often consumed in suboptimal amounts. High sodium diets are associated with increased cardiovascular and renal disease risk, while potassium may have protective properties. Consequently, patients at risk of cardiovascular and renal disease are urged to follow these recommendations, but dietary adherence is often low due to high sodium and low potassium content in processed foods. Adequate monitoring of intake is essential to guide dietary advice in clinical practice and can be used to investigate the relationship between intake and health outcomes. Daily sodium and potassium intake is often estimated with 24-h sodium and potassium excretion, but long-term balance studies demonstrate that this method lacks accuracy on an individual level. Dietary assessment tools and spot urine collections also exhibit poor performance when estimating individual sodium and potassium intake. Collection of multiple consecutive 24-h urines increases accuracy, but also patient burden. In this narrative review, we discuss current approaches to estimating dietary sodium and potassium intake. Additionally, we explore alternative methods that may improve test accuracy without increasing burden.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Organic acid chromatography allows the identification of several hundred compounds and the quantification of the main molecules of interest. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from the French society for inborn errors of metabolism (SFEIM) recommends an approach to accredit organic acid chromatography. Validation parameters and recommendations are discussed in this specific framework.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Acylcarnitine profile allows the identification and quantification of more than thirty compounds. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from SFEIM recommends an approach to accredit acylcarnitine profile. Validation parameters and recommendations are discussed in this specific framework.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Amino acid chromatography allows the identification and quantification of more than forty compounds. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from SFEIM recommends an approach to accredit amino acid chromatography. Validation parameters and recommendations are discussed in this specific framework.

Objectives: The primary aim of this study was to determine if urine cultures are more likely to be contaminated in women with pelvic organ prolapse (POP). The secondary aim was to evaluate the test characteristics of a urine dipstick in women with POP., Methods: A retrospective cohort study was conducted of women who presented to the urogynecology clinic between September 1, 2017, and August 31, 2018. Associations between the presence of POP and contaminated urine culture results were estimated using univariable and multivariable analyses. The sensitivity and specificity of a urine dipstick in women with POP were calculated., Results: We included 351 women (143 with and 208 without POP). Women with POP were older (65.4 ± 15.8 vs 60.7 ± 11.0 years, P < 0.01), had a lower body mass index (26.6 ± 4.8 vs 29.2 ± 7.7 kg/m, P < 0.01), and were less likely to have recurrent urinary tract infections (3.5% vs 9.6%, P=0.03). Women with POP were more likely to have a contaminated urine culture than women without POP (55.9% vs 40.9%, P < 0.01). Rates of contaminated urine culture were higher in women with stage 3 and 4 prolapse than in women with stage 2 prolapse (59.6% vs 41.0%, P < 0.01). On multivariate analysis, the odds of contaminated urine culture remained higher in women with POP (odds ratio, 1.89; 95% confidence interval, 1.20-2.99). In women with POP, the sensitivity (23.5%) and positive predictive value (66.7%) of a urine dipstick were poor., Conclusions: Women with POP are more likely to provide a contaminated urine culture when collecting a midstream urine specimen.

Urine samples are commonly collected from young children to diagnose or exclude urinary tract infections, but collection from precontinent children is challenging. Each collection method has advantages and limitations. Non-invasive methods (urine pads, bags, clean catch) are convenient but can be time-consuming and are limited by sample contamination. Voiding stimulation methods (bladder-lumbar stimulation, Quick-Wee) can expedite clean catch collection. Invasive methods (catheter, suprapubic aspiration) can be more reliable, but require expertise to perform and cause pain for the child. This article reviews each collection method, and describes collection procedures, indications and strategies to optimise success and reduce contamination., Competing Interests: Competing interests: JK is the lead author of previous studies for the Quick-Wee method, which is included in this review., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Although liquid biopsies offer many advantages over tissue biopsies, they are not yet standard practice. An important reason for the lack of implementation is the unavailability of well standardized techniques and guidelines, especially for pre-analytical conditions which are an important factor causing the current sensitivity issues. To overcome these limitations, we investigated the effect of several pre-analytical conditions on the concentration of cell-free DNA (cfDNA) and cellular genomic DNA (gDNA) contamination. Urine samples from healthy volunteers (HVs) and cancer patients were collected and processed according to specific pre-analytical conditions. Our results show that in samples with a relatively small volume more than 50% of the cfDNA can be found in the first 50 mL of the urine sample. The total DNA concentration increased again when samples were collected more than 3.5 hours apart. Adding preservative to urine samples is recommended to obtain high concentrations of cfDNA. To remove the cellular content, high speed centrifugation protocols as 4,000g 10min or 3,000g 15min are ideal for urine collected in cfDNA Urine Preserve (Streck). Although this study was a pilot study and needs to be confirmed in a larger study population, clear trends in the effect of several pre-analytical conditions were observed., Competing Interests: The authors have declared that no competing interests exist.

Urinalysis is a commonly utilized laboratory test, and analysis of urine has been studied and used since ancient times. Urine contains a wide array of metabolites that can provide information regarding the current physiologic state of the body and clinical manifestations of disease. In this review, we discuss the mechanics of the dry chemistry component of the urine dipstick such as the reaction principles underlying various assays and potential effects of collection and storage on results. Additionally, we discuss the benefits and limitations of the urine dipstick as it pertains to its use as a low-cost tool in point-of-care settings and the reasoning for a lack of its use as a broad screening tool.

The pre-analytical step of the cytobacteriological examination of urine (CBEU) is one of the most critical in microbiology. The objectives of our study were to determine the rate of urinary contamination and to analyze the factors that would facilitate this in order to propose solutions to this problem., Method: This is a 26-month descriptive study including all CBEU requests to our laboratory. Urine was treated in accordance with the recommendations of the medical microbiology recommendations. Urine was considered contaminated in the case of polymorphic culture with at least three different types of germs with a count from 10 3 CFU/mL., Results: We collected 16,412 CBEU requests. Urine was contaminated in 4,830 cases (29.43%). Of the contaminated urine, 39.23% (n=1,895) was from emergency departments, 79.44% (n=3,837) was collected in the middle of the stream, 69.83% (n=3,373) was from a female patient and 16.34% (n=789) was from children under the age of 5., Discussion and Conclusion: To reduce urine contamination, quality instructions describing sampling procedures should be available and samples in the middle of the stream and through the collection adhesive bags should be replaced by sus-pubic puncture samples in children, whenever the profit/risk ratio of this method is favourable.

Introduction: Urinary tract infections are frequently encountered in general practice. For diagnosis, it is recommended to obtain a midstream specimen of urine and immediately inoculate on agar plates, preserve in boric acid or keep cooled until analysis. This study investigated if urine samples produced at home by patients with suspected urinary tract infections are done in accordance with recommendations., Methods: The project was conducted at three Danish general practice clinics. When a patient or relative delivered a urine sample produced at home on suspicion of urinary tract infection, he or she was asked to fill in an anonymous questionnaire about the production of the sample., Results: A total of 60 patients (48 females and 12 males) completed the questionnaire. In all, 22 urine samples were midstream specimen urine. The median time to delivery was 60 minutes. Five samples were delivered within ten minutes of production and therefore characterised as immediate delivery in this study. Eight samples were cooled until delivery; 13.3% met urine analysis recommendations., Conclusion: The findings of this study suggest that urine samples produced at patients' own home on suspicion of urinary tract infection rarely meet recommendations required for further diagnostic analysis., Funding: none., Trial Registration: not relevant., (Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.)

Objective: To assess agreement between established methods of estimating salt intake from spot urine collections and 24 h urinary Na (24hUNa) and then to develop a valid formula that can be used in the Iranian population to estimate salt intake from spot urine samples., Design: A validation study. Three spot urine samples were collected (fasting second-void morning; afternoon; evening) on the same day as a 24 h urine collection. We estimated 24hUNa from spot specimens using the Kawasaki, Tanaka and INTERSALT equations. Two new formulas were developed, the Iran formula 1 (Iran 1) and Iran formula 2 (Iran 2), based on our population characteristics., Setting: Iranian adults recruited in 2014-2015., Participants: Healthy volunteer adults aged ≥18 years., Results: With all three spot urine specimens, predicted population 24hUNa was underestimated based on the INTERSALT equation (-469 to -708 mg/d; all P < 0·05) and conversely overestimation occurred with the Kawasaki equation (926 to 1080 mg/d; all P < 0·01). The Tanaka equation produced comparable estimates to measured 24hUNa (-151 to 86 mg/d; all P > 0·49). The newly derived formulas, Iran 1 and Iran 2, showed less mean bias than the established equations (Iran 1: 43 to 80 mg/d, all P > 0·55; Iran 2: 22 to 90 mg/d, all P > 0·50)., Conclusions: In this Iranian sample, the Tanaka equation and newly derived formulas produced group-level estimates comparable to measured 24hUNa. The newly developed formulas showed less mean bias than established equations; however, they need to be tested for generalization in a larger sample.

Background: Preliminary data suggest that the urinary microbiome may play a role in bladder cancer. Information regarding the most suitable method of collecting urine specimens is needed for the large population studies needed to address this. To compare microbiome metrics resulting from 16S ribosomal RNA gene sequencing between midstream, voided specimens and those obtained at cystoscopy., Methods: Adults, with a history of superficial urothelial cell carcinoma (non-muscle invasive bladder cancer) being followed with periodic surveillance cystoscopy had a urine sample collected by a mid-stream, voided technique and then from the bladder at cystoscopy. Urine samples underwent 16S ribosomal RNA gene sequencing on the Illumina MiSeq platform., Results: 22 subjects (8 female, 14 male) were included. There was no significant difference in beta diversity (diversity between samples) in all samples between collection methods. However, analysis by sex revealed a difference between voided and cystoscopy samples from the same individual in males (p = 0.006, Adonis test) but not in females (p = 0.317, Adonis test). No differences were seen by collection method in any alpha diversity (diversity within a sample) measurement or differential abundance of taxa., Conclusions: Beta diversity of the urine microbiome did differ by collection method for males only. This suggests that the urinary microbiomes of the two collection methods are not equivalent to each other, at least in males, which is the sex that bladder cancer occurs most frequently in. Therefore, the same collection method within a given study should be used.

Purpose: The purpose of this quality improvement project was to reduce catheter-associated urinary tract infection (CAUTI) risk for female patients by implementing a female external urinary collection (FEUC) device with suction as an alternative to indwelling catheter (IDC)., Participants and Setting: Participants were female patients admitted to our 386-bed community hospital in Southern California and who required urinary management., Approach: We implemented a comprehensive CAUTI prevention program in 2014 that was in place for 1.5 years before this project was started. The CAUTI prevention program was based on the US Center for Disease Control and Prevention's CAUTI prevention recommendations. To supplement our CAUTI prevention efforts in our female patients, we implemented the FEUC device in our intensive care, telemetry, medical-surgical, orthopedic, and acute rehabilitations inpatient care units. Indwelling catheter use and CAUTI cases were identified by our Infection Prevention department., Outcomes: Prior to introduction of the FEUC device, in 2015, the baseline female IDC utilization rate was 31.7% (7181 IDC device-days/22,656 patient-days) and the female CAUTI rate was 1.11 (8 cases/7181 IDC device-days) per 1000 days. Following introduction of the device, both rates declined. In 2016, the IDC utilization rate was 29.7% (P = .000) and the CAUTI rate was 0% (P =.005). We continued to observe a reduction in 2017 IDC utilization rates of 26% (P = .000); the 2017 CAUTI rate of 0.90 was not significantly different to our prior year rate (P = .726)., Implications for Practice: We found that the introduction of the FEUC device reduced the risk for CAUTI. We will continue to prioritize the use of external devices for urinary management to help reduce the risk of our patients developing CAUTI.

Background: Antibiotic stewardship efforts should standardize treatment of common infections when possible. Urinary tract infections (UTIs) are common in children and require appropriate diagnostic methods and treatment. A pediatric emergency department (ED) identified an opportunity to improve care by standardizing uncomplicated UTI diagnostic testing and treatment according to local bacterial resistance patterns from January 2017 to December 2018., Methods: Using the Model for Improvement, researchers undertook a quality improvement (QI) initiative to standardize the diagnosis and treatment of uncomplicated UTI in children ages 3 months to 12 years in a pediatric ED. Multiple Plan-Do-Study-Act (PDSA) cycles were used, engaging both nurses and physicians, to implement an evidence-based clinical algorithm. Primary aims were to achieve 100% of targeted patients with suspected UTI having appropriately ordered and collected specimens and to increase the frequency of targeted patients receiving algorithm-recommended antibiotics at discharge to 80%. Balancing measures included ED length of stay and revisits to the ED related to UTI., Results: During this initiative, 458 children were assessed for UTI, of whom 75 received a UTI diagnosis. Guideline-concordant urine collection procedure improved from 54.7% to 96.2%. After project initiation, 100% of all antibiotic prescriptions for UTI were guideline-concordant. These changes have been sustained for 19 months since the initiative began. There was no change in UTI-related ED revisits or ED length of stay., Conclusions: This QI initiative achieved standardization of specimen collection and treatment for pediatric UTI in the ED setting, and no adverse outcomes were observed at the institution., (Copyright © 2019 The Joint Commission. Published by Elsevier Inc. All rights reserved.)

Stability of a measurand in a specimen is a function of the property variation over time in specific storage conditions, which can be expressed as a stability equation, and is usually simplified to stability limits (SLs). Stability studies show differences or even inconsistent results due to the lack of standardized experimental designs and heterogeneity of the chosen specifications. Although guidelines for the validation of sample collection tubes have been published recently, the measurand stability evaluation is not addressed. This document provides an easy guideline for the development of a stability test protocol based on a two-step process. A preliminary test is proposed to evaluate the stability under laboratory habitual conditions. The loss of stability is assessed by comparing measurement values of two samples obtained from the same patient and analyzed at different time points. One of them is analyzed under optimal conditions (basal sample). The other is stored under specific stability conditions for a time set by the laboratory (test sample). Differences are expressed using percentage deviation (PD%) to facilitate comparison with specifications. When the preliminary test demonstrates instability, a comprehensive test is proposed in order to define the stability equation and to specify SLs. Several samples are collected from a set of patients. The basal sample is analyzed under optimal conditions, whereas analysis of test samples is delayed at time intervals. For each patient PD% is calculated as the difference between measurements for every test sample and its basal one and represented in a coordinate graph versus time.

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., (Copyright © 2018 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Background: The emergence of different viral infections during the last decades like dengue, West Nile, SARS, chikungunya, MERS-CoV, Ebola, Zika and Yellow Fever raised some questions on quickness and reliability of laboratory diagnostic tests for verification of suspected cases. Since sampling of blood requires medically trained personal and comprises some risks for the patient as well as for the health care personal, the sampling by non-invasive methods (e.g. saliva and/ or urine) might be a very valuable alternative for investigating a diseased patient., Main Body: To analyse the usefulness of alternative non-invasive samples for the diagnosis of emerging infectious viral diseases, a literature search was performed on PubMed for alternative sampling for these viral infections. In total, 711 papers of potential relevance were found, of which we have included 128 in this review., Conclusions: Considering the experience using non-invasive sampling for the diagnostic of emerging viral diseases, it seems important to perform an investigation using alternative samples for routine diagnostics. Moreover, during an outbreak situation, evaluation of appropriate sampling and further processing for laboratory analysis on various diagnostic platforms are very crucial. This will help to achieve optimal diagnostic results for a good and reliable case identification.

The quantification of urine albumin is a common practice in Medical Biology laboratories. It allows the assessment of renal injury in common pathologies and many studies have confirmed its role in the diagnosis and prognosis of these disorders. The physicochemical characteristics of albumin in the urine, very different from those in the blood, do not allow the use of the same standardized assay techniques for the blood albumin determination and make it difficult its quantification. Indeed, because of a physiological fragmentation phenomenon, urinary albumin is present in the urine as various small specific peptides. We will present here the main methods of determination of albumin in the urine, which are immuno-turbidimetric and immuno-nephelometric methods, high performance liquid chromatography with steric exclusion and liquid chromatography coupled with mass spectrometry. Currently, immunoanalysis techniques are the most used and are not standardized; large bias can be found between the different kits. This observation calls for a standardization of its determination in the urine.

Urinary proteins or urinary albumin exhibit a high intra individual variability. Therefore, urine collected during 24 hours has been recognized as a reference biological fluid for usual values determination. However, urine collection during a day is difficult and numerous studies have been performed to replace the "gold standard" with measures on random samples and results given as protein/creatinine ratio or albumin/creatinine ratio, to decrease the variability. The paper presents the populations where ratios are well correlated with protein excretion, the cut-off values recommended in clinical settings and the limits of using ratio rather than 24 h excretion.

Many studies have shown that the urinary tract harbours its own microbial community known as the urinary microbiota, which have been implicated in urinary tract disorders. This observation contradicts the long-held notion that urine is a sterile biofluid in the absence of acute infection of the urinary tract. In light of this new discovery, many basic questions that are crucial for understanding the role of the urinary microbiota in human health and disease remain unanswered. Given that the urinary microbiota is an emerging area of study, optimized techniques and protocols to identify microorganisms in the urinary tract are still being established. However, the low microbial biomass and close proximity to higher microbial biomass environments (for example, the vagina) present distinct methodological challenges for microbial community profiling of the urinary microbiota. A clear understanding of the unique technical considerations for obtaining and analysing low microbial biomass samples, as well the influence of key elements of experimental design and computational analysis on downstream interpretation, will improve our ability to interpret and compare results across methods and studies and is relevant for studies profiling the urinary microbiota and other sites of low microbial abundance.

Today, there is no reference method for the measurement of urinary proteins. The difficulties are that urine is a very complex biological fluid, and that there are a high intra-and inter-individual variability in the protein excretion rate. Progress has been made during the last thirty years, but high analytical variability persists among the colorimetric or turbidimetric methods used for urinary proteins measurement.

The preanalytical phase is a key step in urinary protein measurement. It is a complex step, which includes urine sampling, storage and transport to the laboratory and preparation for analysis of the specimen. It can lead to numerous errors, since urine sampling is made by the patient himself. According to different cases, the procedures for urine sampling are presented in appendix 1 to 4. The aim of the presented guidelines is to improve the preanalytical step. In addition to the sampling made by a well-informed patient, the laboratory has to optimize transport and sample preservation, according to the analytes. The 24-hour urine collection is divided into aliquots with commercially available systems. Urinary proteins are measured on samples stored without preservatives. When 24-hour urine collection is not possible, a mid-stream urine sample is the most appropriate sample for protein measurement.

Measurement of urine albumin has been introduced in the new classification of kidney disease (KD) as a marker for detecting, monitoring and predicting KD. Currently, the measure is not standardized. The variability of results obtained with commercially available procedures is important and can lead to misclassification of patients. Analytical standardization, started in 2007, is in progress. SRM 2925 primary reference material, SRM 3666 secondary reference material and liquid chromatography isotope dilution mass spectroscopy (LC-IDMS) reference measurement procedure are being validated by the National Institute of Standards and Technology (NIST). This report presents strategies and difficulties for developing this reference system.

Urine is an easily accessible biological fluid. This availability makes it tempting for a direct analysis of urinary parameters by physicians. Urinary proteins, that are interesting markers for several pathologies, are detected by urinary strips, rapidly and at a low cost. However, to ensure an optimal use of urinary strips, one may be familiar to their characteristics and their limits. This paper details the available urinary strips used for the detection of urinary proteins and urinary albumin, as well as their analytical performances in clinical conditions such as pregnancy, chronic renal disease, diabetes or for the screening of general populations.

Background Several approaches exist to screen neonates for congenital cytomegalovirus infection. We here describe a new method using cellulose pads for urine collection and its evaluation in an experimental and a clinical setting. Methods We systematically tested the effect of storage duration of the pads after exposure to cytomegalovirus-positive urine, meconium contamination and specimen handling on the cytomegalovirus load and the detection rate. Further, the method was tested in clinical practice in a cohort of 500 neonates. Results Following exposure of urine pads with cytomegalovirus-positive urine, the viral load decreased after 15 min, 12 h, 24 h, and 7 days to 63.2%, 42.1%, 31.6%, and 9.3% of the baseline value. Cytomegalovirus detection rate after seven days was 100%. Contamination with meconium resulted in a comparable reduction of the viral load. The detection rate for dried urine pads after seven days was 93.3%. In clinical practice, urine collection from pads was successful in 73.6% by the first attempt and in 26.4% by the second attempt. Conclusions Urine collection using cellulose pads seems feasible regardless of a reduction of the cytomegalovirus load due to exposure to the pad itself or to meconium. Drying of the exposed urine pad should be avoided.

Sodium intake is assessed using 24 h urinary excretion; it is important to ensure urine collections are complete. This can be validated by monitoring urinary excretion of p-aminobenzoic acid (PABA) administered in tablet form at intervals during the urine collection. Unavoidable change of PABA tablet supplier and analytical procedure required re-establishment of the thresholds consistent with a complete collection. Reference ranges for adults without reported intestinal or renal disease were determined by HPLC (70-103%) and colorimetry (84-120%). Some individuals excreted a small, measurable amount of PABA the following day but this did not represent the balance of the PABA ingested. Assay of the PABA tablets confirmed the stated dose (80 mg) and demonstrated their stability up to 8 years (duration of study) at room temperature. These tablets have been used and the reference ranges applied in UK national population surveys since 2008.

Objectives: The detection of an STI agent in a urogenital tract (UGT) specimen from a young child is regarded as being indicative of sexual abuse. However, the probabilities of contamination events that could conceivably lead to STI positive specimens in the absence of sexual contact are unclear. The objective was to estimate the potential for fingers that have come in contact with Chlamydia trachomatis- positive urine to detectably contaminate C. trachomatis- negative urine., Methods: The study design was based on self-experimentation. Dilutions of C. trachomatis elementary bodies (EBs) were prepared. A participant contacted an EB dilution then a urine surrogate specimen. The experiment was performed by three participants using three C. trachomatis isolates, of genotype E, F and B. Two surrogate urine contact methods were used to mimic contamination of a carer assisting with a child's urine collection. All EB dilutions and urine surrogate specimens were subjected to C. trachomatis assay and quantification in a real-time PCR-based diagnostic system., Results: The amplimer crossing point (Cq) for EB dilutions was 10.0±1.6 less than for corresponding finger contacted urine specimens, which corresponds to ~10 µL of EB suspension transferred. This was largely independent of participant identity, C. trachomatis strain or EB dilution. Hand decontamination led to large reductions in EBs transferred, but transfer remained consistently detectable. Recent Cq data from C. trachomatis- positive clinical urine specimens were collated, and 20% clearly contained sufficient C. trachomatis to detectably contaminate another specimen by finger-mediated transfer, as in this experiment., Conclusions: This study directly demonstrated the potential for urine contaminated fingers to convert a C. trachomatis- negative urine specimen to C. trachomatis positive as a result of contact. Accordingly, procedures for urine specimen collection, particularly from children, need to be designed to prevent contamination., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

In clinical practice, patients provide samples that violate specimen collection guidelines. As no research exists to guide clinical practice for such situations involving sexually transmitted infections (STIs), we reviewed our clinical data to determine how to proceed when patients provided urine specimen >30mL. We tracked the quantity of urine, test outcomes, and whether or not patients returned to provide subsequent samples when notified to do so. Over 6months, 33 patients provided overfilled samples; we submitted 70% (n=23/33). From the submitted specimens, 5 infections were identified from 4 patients: all were positive for chlamydia and 1 for gonorrhea and chlamydia. This yielded the following positivity rates: 17.4% for chlamydia (n=4/23), and 4.3% for gonorrhea (n=1/23). For the group, the positivity rate was 17.4% (4 of 23 patients with infections), or 21.7% (5 infections from 23 patients). Lastly, only 60% of the patients instructed to return to clinic for retesting did so. Due to the possibility of false negative results, the ability to detect infections in overfilled samples, and because patients may not return for retesting, we recommend submitting overfilled samples, while also notifying patients to return to retest. This approach could maximize diagnostic rates, at least within STI testing clinics., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to compare bacteriological urinalysis findings using 3 urinary sample collection methods (clean stoma catheterization, urine dripping from the stoma, urine collected from the clean urostomy pouch) in ileal conduit urinary diversion patients., Design: Randomized controlled trial., Sample and Setting: Twenty-seven patients with ileal conduit urinary diversion from an outpatient urology clinic were enrolled; 9 patients were seen twice, for a total of 36 subjects and comparisons., Methods: Data were collected during a clinic visit by a trained research nurse. Patients were randomized into 2 groups: group A had the first urine sample collected by clean stoma catheterization, followed by sample collection by urine dripping from the stoma; group B had the first urine sample collection by urine dripping from the stoma, followed by sample collected by clean stoma catheterization. All patients had a third urine sample collected from a factory-clean urostomy pouch. Bacteriological urinalysis findings were compared among methods. Descriptive analyses were summarized using mean, percentage, and frequency. The mean ages of the patients between the groups were compared with the t test. Other between-group comparisons were performed using the Fisher exact test. Urinary culture finding differences among the same patients were evaluated using the McNemar test. Sensitivity and specificity of the different urine sample collection methods were calculated assuming urine sample collection by catheterization as a reference method., Results: Uropathogen bacteria were detected in urinary culture in 16 of 36 samples (44%) collected by clean stoma catheterization, 15 of 36 samples (42%) collected by urine dripping directly from the stoma, and 13 of 35 samples (37%) collected from the clean urostomy pouch. Significant differences among the urine collection methods were not detected. Assuming catheterization as the most reliable method of sample collection, the sensitivity and specificity of the urine dripping from stoma collection method were 81.3% and 90.0%, respectively. The sensitivity and specificity of the urostomy pouch collection method were 73.3% and 90.0%, respectively. Among the same patients, there were no significant differences in the incidence of uropathogen bacteria when clean stoma catheterization was compared with urine dripping from the stoma and urostomy pouch methods., Conclusion: This study provides clinically relevant information regarding urine collection methods in ileal conduit patients. Urinary sample collection by urine dripping directly from the stoma or collected from a clean urostomy pouch provided similar uropathogen bacteria findings compared with sample collection by clean stoma catheterization.

Aims: Bacteria adherent to long-term urinary catheters (LTUC) may give misleading urine culture results. Guidelines in the USA recommend changing LTUC before urine collection to diagnose UTI and before commencing appropriate antimicrobial treatment. However, in the UK there is no such guidance. In this study, we evaluated differences in urine cultures before and after changing LTUC., Methods: In a prospective study in a UK urology department, we made a quantitative and qualitative comparison between paired urines collected before and after catheter change in patients with LTUC. We measured culture growth on a four-point ordinal scale as nil, scanty (< 10 7  cfu/L), moderate (10 7 -10 8  cfu/L) or heavy (> 10 8  cfu/L) and recorded the range of bacterial species isolated. Statistical analysis was by Wilcoxon matched-pairs test., Results: Sixty-six patients (55 males, 11 females) took part in the study. Urines with no growth increased from 7/66 (11%) before change of catheter to 21/66(32%) after change of catheter. Cultures reported as heavy growth (> 10 8  cfu/L) reduced from 48/66 (73%) to 25/66 (38%) after catheter change (p < 0.001). Except for Pseudomonas spp., other organisms were isolated less frequently after catheter change. No Proteus spp. was isolated after catheter change., Conclusions: This study confirms that failure to change long-term catheters before collecting urine for culture may give misleading results. In the interest of accurate diagnosis and antimicrobial stewardship, UK guidelines should recommend changing long-term urinary catheters before collection of urine for culture.

Crystalluria is an imbalance between promoters and inhibitors; the first are the engine of the crystals and the second are made of substances. The biological assays make it possible to demonstrate one or more lithogenic factors observed during the lithiasis. The objective of our work was to study the impact of acidification or alkalization of the urine of lithiasic patients during a cristallurie assessment. All urine in the morning must be stored at room temperature and examined within two-three hours following voiding. 80 lithiasic patients (40 for urinary calcium and 40 for urinary uric acid) were selected from the results of cristalluria: more than 20 calcium-dependent crystals or uric acid crystal/mm 3 . For calcium and uric acid, concentration differences, after acidification and alkalization are observed: r 2 =0.43 (p<0.01) and r 2 =0.36 (p<0.01) respectively. In conclusion, in this lithiasic population with the presence of cystals, this pre-analytical stage is essential for urinary calcium and uric acid, making it possible to establish a diagnosis of certainly for the patient.

For the reliable urinary measurement of calcium, phosphate and uric acid, a pre-analytical process by adding acid or base to urine samples at laboratory is recommended in order to dissolve precipitated solutes. Several studies on different kind of samples and analysers have previously shown that a such pre-analytical treatment is useless. The objective was to study the necessity of pre-analytical treatment of urine on samples collected using the V-Monovette ® (Sarstedt) system and measured on the analyser Architect C16000 (Abbott Diagnostics). Sixty urinary samples of hospitalized patients were selected (n=30 for calcium and phosphate, and n=30 for uric acid). After acidification of urine samples for measurement of calcium and phosphate, and alkalinisation for measurement of uric acid respectively, differences between results before and after the pre-analytical treatment were compared to acceptable limits recommended by the French society of clinical biology (SFBC). No difference in concentration between before and after pre-analytical treatment of urine samples exceeded acceptable limits from SFBC for measurement of calcium and uric acid. For phosphate, only one sample exceeded these acceptable limits, showing a result paradoxically lower after acidification. In conclusion, in agreement with previous study, our results show that acidification or alkalinisation of urine samples from 24 h urines or from urination is not a pre-analytical necessity for measurement of calcium, phosphate and uric acid.

Objective: Young infants are often treated in emergency departments (EDs) for febrile illnesses. Any delay in care or ineffective management could lead to increased patient morbidity and mortality. A standardized ED clinical pathway may improve care for these patients. The objective of this study is to evaluate the impact of a febrile young infant clinical pathway implemented in a large, urban children's hospital ED on the timeliness and consistency of care., Methods: This study used a before-and-after retrospective observational study design comparing 2 separate periods: prepathway from September 2007 through August 2008 and postpathway from September 2009 through August 2010. Subjects were infants aged 56 days or younger presenting with a rectal temperature of 38.0°C or higher. Patients were excluded if they were transferred from another hospital or if they developed a fever after initial presentation., Results: Five hundred twenty infants were enrolled. The mean time to urine collection and time to the first antibiotic administration were reduced after pathway implementation (23-minute reduction to urine collection vs 36-minute reduction to the first antibiotic administration). There was improvement in the proportion of infants who received the pathway-specific antibiotics based on age (odds ratio, 7.2; 95% confidence interval, 4.4, 11.9) and the proportion of infants who were administered acyclovir based on pathway guidelines (odds ratio, 8.8; 95% confidence interval, 2.9-30.0)., Conclusions: An ED-based febrile young infant clinical pathway improved the timeliness of initiation of work-up as measured by urine collection and of therapy by an earlier administration of the first antibiotic, as well as decreased variability of care.

Background: Urinalysis testing is frequently ordered in the emergency department (ED), but contamination of urine specimens limits the interpretation of results. The mid-stream, clean-catch (MSCC) procedure for urine specimen collection is recommended to decrease contamination rates, but without instructions this procedure has poor compliance., Objective: To evaluate the effectiveness of written instructions alone, we analyzed the rate of specimen contamination, defined by presence of squamous epithelial cells (SECs) and culture results, in the ED after posting information on the MSCC procedure., Methods: Instructions in simple English for the MSCC procedure were posted in all patient-accessible restrooms in the ED. Frequency of contamination, defined microscopically as > 5 SECs per high-powered field or through growth of mixed or non-pathologic flora on urine culture, was determined over a 3-month period for comparison to historical controls from the previous year., Results: During the intervention period, 754 urinalyses were sent, with 392 contaminated specimens (51.98%), and 193 urine cultures were sent, with 77 contaminated results (39.8%). Historical controls from the previous year yielded 827 urinalyses sent, with 430 contaminated (51.99%), and 251 urine cultures, with 125 contaminated results (49.8%). The difference between groups was not significant for urinalysis (p = 0.99) or urine culture (p = 0.13)., Conclusions: A poster-based educational intervention with instructions on MSCC procedure failed to decrease contamination rates in this ED-based study. Possible explanations include poor compliance with MSCC technique in the ED, or poor efficacy of this technique at decreasing contamination rates. These results may indicate that other efforts are necessary to improve urine collection methods., (Copyright © 2016 Elsevier Inc. All rights reserved.)

We retrospectively evaluated 131 patients with contaminated urine cultures during a 12-month period. Sixty-four patients (48.8%) experienced 139 potential complications related to these specimens. The most common complication was inappropriate antibiotic administration (noted in 58 patients [44.3%]). Contaminated urine cultures led to additional diagnostic evaluation and unnecessary antibiotic use., (Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Aims: Urinalysis provides direction in diagnosis and treatment of patients in the emergency department (ED). Midstream urine (MSU) collection from female patients has a high contamination rate. Verbal instruction by nurses to patients reduces contamination but is inconsistent owing to lack of time and professional knowledge. This study aimed to determine if an alternative mode of instruction requiring minimal staff input may be effective., Methods: A pseudorandomised controlled trial was undertaken with 240 female patients for whom urinalysis was clinically required. No change was made to normal practice with regards to verbal instruction. Prior to collecting their sample the intervention cohort received illustrated instruction on how to collect a clean uncontaminated MSU sample. The control cohort received no illustrated instruction. Compared outcomes were rate of contamination on urinalysis, defined as 10 or more epithelial cells per high power field, and answers to a structured patient questionnaire., Results: Contamination rate was reduced from 40% to 25% by the intervention. According to patient survey responses, verbal collection instructions were seldom given and the actions of hand washing, cleaning with a towelette, and voiding then stopping were significantly higher in the intervention group. The illustrations were well received by over 95% of patients and were considered to be clear and effective especially for patients with reading difficulties and/or from a non-English speaking background., Conclusions: Illustrated urine collection instructions were well accepted by female ED patients, improved the rate of proper MSU collection and reduced the rate of urinalysis contamination in the ED., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Numerous metabolic profiling pipelines have been developed to characterize the composition of human biofluids and tissues, the vast majority of these being for studies in adults. To accommodate limited sample volume and to take into account the compositional differences between adult and infant biofluids, we developed and optimized sample handling and analytical procedures for studying urine from newborns. A robust pipeline for metabolic profiling using NMR spectroscopy was established, encompassing sample collection, preparation, spectroscopic measurement, and computational analysis. Longitudinal samples were collected from five infants from birth until 14 months of age. Methods of extraction and effects of freezing and sample dilution were assessed, and urinary contaminants from breakdown of polymers in a range of diapers and cotton wool balls were identified and compared, including propylene glycol, acrylic acid, and tert-butanol. Finally, assessment of urinary profiles obtained over the first few weeks of life revealed a dramatic change in composition, with concentrations of phenols, amino acids, and betaine altering systematically over the first few months of life. Therefore, neonatal samples require more stringent standardization of experimental design, sample handling, and analysis compared to that of adult samples to accommodate the variability and limited sample volume.

Background and Objectives: Urinary tract infection (UTI) screening in febrile young children can be painful and time consuming. We implemented a screening protocol for UTI in a high-volume pediatric emergency department (ED) to reduce urethral catheterization, limiting catheterization to children with positive screens from urine bag specimens., Methods: This quality-improvement initiative was implemented using 3 Plan-Do-Study-Act cycles, beginning with a small test of the proposed change in 1 ED area. To ensure appropriate patients received timely screening, care teams discussed patient risk factors and created patient-specific, appropriate procedures. The intervention was extended to the entire ED after providing education. Finally, visual cues were added into the electronic health record, and nursing scripts were developed to enlist family participation. A time-series design was used to study the impact of the 6-month intervention by using a p-chart to determine special cause variation. The primary outcome measure for the study was defined as the catheterization rate in febrile children ages 6 to 24 months., Results: The ED reduced catheterization rates among febrile young children from 63% to <30% over a 6-month period with sustained results. More than 350 patients were spared catheterization without prolonging ED length of stay. Additionally, there was no change in the revisit rate or missed UTIs among those followed within the hospital's network., Conclusions: A 2-step less-invasive process for screening febrile young children for UTI can be instituted in a high-volume ED without increasing length of stay or missing cases of UTI., (Copyright © 2016 by the American Academy of Pediatrics.)

Background: It is not clear which young children presenting acutely unwell to primary care should be investigated for urinary tract infection (UTI) and whether or not dipstick testing should be used to inform antibiotic treatment., Objectives: To develop algorithms to accurately identify pre-school children in whom urine should be obtained; assess whether or not dipstick urinalysis provides additional diagnostic information; and model algorithm cost-effectiveness., Design: Multicentre, prospective diagnostic cohort study., Setting and Participants: Children < 5 years old presenting to primary care with an acute illness and/or new urinary symptoms., Methods: One hundred and seven clinical characteristics (index tests) were recorded from the child's past medical history, symptoms, physical examination signs and urine dipstick test. Prior to dipstick results clinician opinion of UTI likelihood ('clinical diagnosis') and urine sampling and treatment intentions ('clinical judgement') were recorded. All index tests were measured blind to the reference standard, defined as a pure or predominant uropathogen cultured at ≥ 10(5) colony-forming units (CFU)/ml in a single research laboratory. Urine was collected by clean catch (preferred) or nappy pad. Index tests were sequentially evaluated in two groups, stratified by urine collection method: parent-reported symptoms with clinician-reported signs, and urine dipstick results. Diagnostic accuracy was quantified using area under receiver operating characteristic curve (AUROC) with 95% confidence interval (CI) and bootstrap-validated AUROC, and compared with the 'clinician diagnosis' AUROC. Decision-analytic models were used to identify optimal urine sampling strategy compared with 'clinical judgement'., Results: A total of 7163 children were recruited, of whom 50% were female and 49% were < 2 years old. Culture results were available for 5017 (70%); 2740 children provided clean-catch samples, 94% of whom were ≥ 2 years old, with 2.2% meeting the UTI definition. Among these, 'clinical diagnosis' correctly identified 46.6% of positive cultures, with 94.7% specificity and an AUROC of 0.77 (95% CI 0.71 to 0.83). Four symptoms, three signs and three dipstick results were independently associated with UTI with an AUROC (95% CI; bootstrap-validated AUROC) of 0.89 (0.85 to 0.95; validated 0.88) for symptoms and signs, increasing to 0.93 (0.90 to 0.97; validated 0.90) with dipstick results. Nappy pad samples were provided from the other 2277 children, of whom 82% were < 2 years old and 1.3% met the UTI definition. 'Clinical diagnosis' correctly identified 13.3% positive cultures, with 98.5% specificity and an AUROC of 0.63 (95% CI 0.53 to 0.72). Four symptoms and two dipstick results were independently associated with UTI, with an AUROC of 0.81 (0.72 to 0.90; validated 0.78) for symptoms, increasing to 0.87 (0.80 to 0.94; validated 0.82) with the dipstick findings. A high specificity threshold for the clean-catch model was more accurate and less costly than, and as effective as, clinical judgement. The additional diagnostic utility of dipstick testing was offset by its costs. The cost-effectiveness of the nappy pad model was not clear-cut., Conclusions: Clinicians should prioritise the use of clean-catch sampling as symptoms and signs can cost-effectively improve the identification of UTI in young children where clean catch is possible. Dipstick testing can improve targeting of antibiotic treatment, but at a higher cost than waiting for a laboratory result. Future research is needed to distinguish pathogens from contaminants, assess the impact of the clean-catch algorithm on patient outcomes, and the cost-effectiveness of presumptive versus dipstick versus laboratory-guided antibiotic treatment., Funding: The National Institute for Health Research Health Technology Assessment programme.

This study was done to clarify the optimal number and type of casual urine specimens required to estimate urinary sodium/potassium (Na/K) ratio in individuals with high blood pressure. A total of 74 individuals with high blood pressure, 43 treated and 31 untreated, were recruited from the Japanese general population. Urinary sodium, potassium and Na/K ratio were measured in both casual urine samples and 7-day 24-h urine samples and then analyzed by correlation and Bland-Altman analyses. Mean Na/K ratio from random casual urine samples on four or more days strongly correlated with the Na/K ratio of 7-day 24-h urine (r=0.80-0.87), which was similar to the correlation between 1 and 2-day 24-h urine and 7-day 24-h urine (r=0.75-0.89). The agreement quality for Na/K ratio of seven random casual urine for estimating the Na/K ratio of 7-day 24-h urine was good (bias: -0.26, limits of agreements: -1.53-1.01), and it was similar to that of 2-day 24-h urine for estimating 7-day 24-h values (bias: 0.07, limits of agreement: -1.03 to 1.18). Stratified analyses comparing individuals using antihypertensive medication and individuals not using antihypertensive medication showed similar results. Correlations of the means of casual urine sodium or potassium concentrations with 7-day 24-h sodium or potassium excretions were relatively weaker than those for Na/K ratio. The mean Na/K ratio of 4-7 random casual urine specimens on different days provides a good substitute for 1-2-day 24-h urinary Na/K ratio for individuals with high blood pressure.

Objective: To systematically review the literature and synthesize data on the diagnostic performance of a 12-hour urine collection for proteinuria in pregnant women with suspected preeclampsia., Data Sources: We performed a literature search of PubMed, Embase, Scopus, ClinicalTrials.gov, and CINAHL through February 2014 using key words related to gestational hypertension, preeclampsia, and proteinuria., Methods of Study Selection: Studies that contained results of both the 12-hour and 24-hour urine collection in the same patients were eligible., Tabulation, Integration, and Results: Three independent reviewers abstracted test performance characteristics from each study for the performance of a 12-hour urine collection for the diagnosis of proteinuria defined as 300 mg in 24 hours. Diagnostic meta-analysis was performed to obtain summary statistics. Heterogeneity was assessed using the Cochrane Q or I. Receiver operating characteristic curve analysis was used to assess the optimal diagnostic cutpoint for proteinuria from a 12-hour urine collection. Stratified analysis was performed based on whether patients were on bed rest during urine collection. A total of seven studies met inclusion criteria. The 12-hour urine protein was overall highly predictive of proteinuria on 24-hour urine collection area under receiver operating characteristic curve: 0.97 (95% confidence interval [CI] 0.95-0.98). The pooled sensitivity was 92% (95% CI 86-96) and specificity was 99% (95% CI 75-100). The optimal cutpoint based on the receiver operating characteristic curve was 150 mg of protein on 12-hour collection., Conclusion: A 12-hour urine collection compares favorably with a 24-hour urine collection for the diagnosis of proteinuria in women with suspected preeclampsia and has the advantage of convenience and improved clinical efficiency.

Congenital cytomegalovirus infection is traditionally diagnosed by virus detection in saliva or urine. Virus culture was positive in significantly fewer urine samples collected using cotton balls in diapers (55.2%) than with samples collected by bags (93.2%) from newborns screened positive for CMV in saliva. However, polymerase chain reaction was positive in 95% of urine samples regardless of the collection method.

A common practice in sports science is to assess hydration status using the concentration of a single spot urine collection taken at any time of day for comparison against concentration (specific gravity, osmolality, color) thresholds established from first morning voids. There is strong evidence that this practice can be confounded by fluid intake, diet, and exercise, among other factors, leading to false positive/negative assessments. Thus, the purpose of this paper is to provide a simple explanation as to why this practice leads to erroneous conclusions and should be curtailed in favor of consensus hydration assessment recommendations.