Comparative analysis of different loop types for urine culture collection: Implications for quantitative bacterial growth and culture results.

We hypothesized that the loop material and size could affect the results of the culture when compared to the calibrated pipette. A total of 484 urine samples were included in the study, and each sample was plated by using different loop types and the calibrated pipette. The bacterial counts per milliliter were calculated and compared, with a focus on the important cutoff values of 10³ and 104 CFU/ml for further identification. When considering the 10³ CFU/ml as cutoff value, 1 µl and 10 µl plastic loops gave the highest sensitivity (86.8 %), whereas the 10 µl metal loop had the lowest sensitivity (64.2 %). For the 104 CFU/ml cutoff value, 1 µl plastic loop inoculation demonstrated the highest sensitivity (75.9 %), while the 10 µl metal loop provided the lowest sensitivity (26.5 %). These results suggest that the single use plastic loops are functional, sensitive, useful especially for critical sample.

Assessment of baby disposable diapers application for urine collection and determination of phthalate metabolites.

The baby disposable diapers were investigated as a sampling material for urine collection and validated for the evaluation of the exposure of children to xenobiotics. Phthalate metabolites detected in urine samples were chosen as proof-of-concept analytes. For the determination of phthalate metabolites in children's urine samples, high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used. Two sampling approaches were compared, namely sterile containers and baby disposable diapers. Thirty urine samples from infants and toddlers were analyzed by both methods in parallel and the results were compared. It was found that for diaper sampling, lower concentrations of the metabolites were observed, however, the general distribution for particular metabolites remains the same for both methods. For most of the metabolites high determination coefficients were obtained, namely 0.9929 for MEHHP, 0.9836 for MMP, 0.9796 for MECPP, and 0.9784 for 2-cx-MMHP. For MEOHP the determination correlation coefficient was 0.9154, while for MBP was - 0.7771 and MEHP was - 0.5228. In general, for diaper sampling an underestimation for 2-cx-MMHP and MEOHP was observed, while for MMP diaper-based approach provides overestimation. However, the proposed procedure confirms the possibility of using baby disposable diapers as a material for the collection of urine samples for biomonitoring purposes and fast screening of phthalates exposure.

CATCH IT: The Effect of Bladder Ultrasound in Decreasing the Time to Collect a Clean-Catch Urine Sample in the Nontoilet-Trained Child: A Randomized Control Trial.

OBJECTIVES: Clean-catch urine is essential in the investigation of an unwell child but can unfortunately be difficult to obtain in nontoilet-trained children. To this end, we compared the difference in time taken to collect clean-catch urine in nontoilet-trained children via the use of point-of-care ultrasound and traditional methods. METHODS: A single-center randomized controlled trial was conducted at an urban pediatric emergency department, recruiting 80 patients, of which 73 underwent data analyses. Participants were randomized to either the control arm, which consisted of the traditional "watch and wait" method of collecting a clean-catch sample, or to the intervention arm, which used point-of-care ultrasound to assess bladder volume and to stimulate the micturition reflex. The primary outcome measured was the mean time taken to collect a clean-catch urine sample. RESULTS: Eighty patients (ultrasound, n = 41; standard care, n = 39) underwent randomization using a random number generator. Seven patients were removed from final analysis due to loss to follow-up for various reasons. Seventy-three patients (ultrasound, n = 37; standard care, n = 36) underwent statistical analysis. The ultrasound group had a median time to clean-catch urine of 40 minutes (interquartile range, 52) and mean time of 52 minutes (standard deviation, 42), and the control group had a median time of 55 minutes (interquartile range, 81), and mean time of 82 minutes (standard deviation, 90). This reached statistical significance (1-tail t test, P = 0.033). The baseline characteristics were similar between both groups for sex and age distribution; however, the mean ages were significantly different (2-tail t test, P = 0.049) with 8.4 months in the control group, and 12.3 months in the ultrasound group. CONCLUSIONS: We found that there was a statistically and clinically significant reduction in mean time taken to collect clean-catch urine in nontoilet-trained children using point-of-care ultrasound compared with the traditional watch and wait method.

Understanding the Barriers to Preventive Pharmacological Therapy Use in Older Patients With Urinary Stone Disease.

INTRODUCTION: Despite compelling clinical trial evidence and professional society guideline recommendations, prescription rates of preventative pharmacological therapy (PPT) for urinary stone disease are low. We sought to understand how patient- and clinician-level factors contribute to the decision to prescribe PPT after an index stone event. METHODS: We identified Medicare beneficiaries with urinary stone disease who had a 24-hour urine collection processed by a central laboratory. Among the subset with a urine chemistry abnormality (ie, hypercalciuria, hypocitraturia, hyperuricosuria, or low urine pH), we determined whether PPT was prescribed within 6 months of their collection. After assigning patients to the clinicians who ordered their collection, we fit multilevel models to determine how much of the variation in PPT prescription was attributable to patient vs clinician factors. RESULTS: Of the 11,563 patients meeting inclusion criteria, 33.6% were prescribed PPT. There was nearly sevenfold variation between the treating clinician with the lowest prescription rate (11%) and the one with the highest (75%). Nineteen percent of this variation was attributable to clinician factors. After accounting for measured patient differences and clinician volume, patients had twice the odds of being prescribed PPT if they were treated by a nephrologist (odds ratio [OR], 2.15; 95% CI, 1.79-2.57) or a primary care physician (OR, 1.78; 95% CI, 1.22-2.58) compared to being treated by a urologist. CONCLUSIONS: These findings suggest that the type of clinician whom a patient sees for his stone care determines, to a large extent, whether PPT will be prescribed.

24-h urine collection in patients with urolithiasis: perspective on renal function.

A prospective observational study involving consecutive patients diagnosed with symptomatic urolithiasis was conducted to evaluate the serial change of urinary protein and 24-h urine chemistry with time after surgical procedures for urolithiasis. A consecutive 24-h urine samples, including calcium, uric acid and citrate were collected before surgical treatments, 4 ~ 8 weeks after surgery and 6 months after surgery. The urinary protein to creatinine ratio was also repeated at each timepoint. Forty-seven patients completed the study. The quantity of 24-h urine chemistry, including calcium, uric acid and citrate, changed over time and tended to increase (p = 0.013, 0.076 and 0.004, respectively), but the changes were not prominent during short-term follow-up. In contrast, the urinary protein to creatinine ratio decreased (p < 0.001) after surgical treatment for symptomatic renal stones, and the change was reflected in short-term follow-up. However, the serial changes in the urinary protein to creatinine ratio were significantly related to the serial changes in the 24-h urinary chemistry (p < 0.001). Surgical decompression for symptomatic urolithiasis could decrease the urinary protein to creatinine ratio, indicating improvement from renal damage, which may be reflected in the increase in 24-h urinary chemistry, including calcium, uric acid and citrate. These results strengthen the previous guidelines for the timing of 24-h urine collection and provide new insight into the optimal timing from the perspective of renal function.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review / ¿Reducen los dispositivos externos de recogida de orina la contaminación de las muestras de orina en mujeres con síntomas de infección urinaria? Una revisión sistemática

Introduction: To evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. Methods: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. Results: Only two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. Conclusions: More studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Introducción: Evaluar el impacto de los dispositivos externos de recogida de orina (DERO) sobre la contaminación en muestras de orina en mujeres con síntomas de infección urinaria. Métodos: Esta revisión siguió la pauta de revisiones sistemáticas de pruebas diagnósticas (PROSPERO CRD42021241758). Se realizó una búsqueda en PubMed de estudios de muestras pareadas y ensayos controlados. Se consideraron los estudios que compararon los DERO con procedimientos no invasivos de recogida de orina. Resultados: Solo se hallaron 2 estudios. Ninguno encontró diferencia alguna en la contaminación de las muestras recogidas con DERO y técnicas no invasivas. En el estudio más grande, que incluyó a 1.264 mujeres sintomáticas, el 18,8% de las asignadas a los DERO no pudieron recoger las muestras satisfactoriamente. Conclusiones: Se necesitan más estudios con mujeres con síntomas de infección urinaria para tener datos más consistentes del impacto de estos dispositivos sobre la contaminación de las muestras urinarias.(AU)

Development of a kit for urine collection on filter paper as an alternative for Pompe disease screening and monitoring by LC-HRMS.

Pompe disease (PD) is an inborn error of metabolism caused by α-glucosidase acid enzyme deficiency. It significantly impacts patients' health and life quality and may lead to death in the first few years of life. Among the well-established diagnostic methods, urinary glucose tetrasaccharide (Glc4) screening by high performance-liquid chromatography has been helpful in monitoring Glc4 levels in patients on enzyme replacement therapy, demonstrating therapy efficacy. However, the specimen shipping process from a sample collecting location to a specialized laboratory for monitoring the Glc4 is costly and presents preanalytical challenges. In this work, we developed a filter paper based-urine collection kit to facilitate specimen shipment, and liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) analysis to determine Glc4 and creatinine in dried urine on filter paper. The LC-HRMS was based on a combination of targeted and untargeted screening on the same specimen injection and was successfully developed and validated. Bland-Altman statistics revealed a good relationship between dried and liquid urine samples and Glc4 and creatinine. Glc4 and other metabolites in dried urine showed stability for at least 7 days at 4 and 22 °C, and 3 days at 50 °C. The stability of the analytes and the efficiency of the kit were tested simulating real conditions by sending it by post. After two days in transit without refrigeration, the stability of compounds was maintained, showing the reliability of the urine collection kit and analysis method to determine the PD biomarker Glc4.

Review on adherence of the literature to official recommendations on albuminuria harmonization and standardization.

Albuminuria standardization is a key issue to produce reliable and equivalent results between laboratories. We investigated whether official recommendations on albuminuria harmonization are followed in the literature. The PubMed database was searched from June 1 to September 26, 2021. The search terms included urine albumin, urine albumin-to-creatinine ratio (uACR), and albuminuria. A total of 159 articles were considered eligible; 50.9 % reported the type of urine collection. Specifically, 58.1 % collected a random spot urine specimen, 21 % collected a first morning void, and 6.2 % collected a 24-h specimen. Overall, 15 % of articles reported data on sample shipping, storage, and centrifugation and 13.3 % mentioned the preanalytical phase without any data on albuminuria. The method for albuminuria was properly described in 31.4 % of articles; of these, 54.9 % used immunological methods, and 8.9 % contained errors or missing data. Most articles (76.7 %) expressed test results as albuminuria-to-creatininuria ratio. Different decision levels were utilized in 130 articles; of these, 36 % used a decision level of ≤30 mg/g creatininuria and 23.7 % used three decision levels (≤30, 30-300, and ≥300 mg/g). The failure to follow guidelines on albuminuria harmonization was mainly found in the preanalytical phase. The poor awareness of the importance of preanalytical steps on test result may be a possible explanation.

Experiences of urine collection devices during suspected urinary tract infections: a qualitative study in primary care.

BACKGROUND: Up to 30% of urine samples from women with suspected urinary tract infection (UTI) are contaminated and need to be repeated, burdening health services and delaying antibiotic prescription. To prevent contamination, midstream urine (MSU) sampling, which can be difficult to achieve, is recommended. Urine collection devices (UCDs) that automatically capture MSU have been proposed as a solution. There are few studies exploring women's experiences of using such devices. AIM: To explore women's experiences of urine collection and the use of UCDs during a suspected UTI. DESIGN AND SETTING: An embedded qualitative study in a UK randomised controlled trial (RCT) of UCDs among women attending primary care for UTI symptoms. METHOD: Semi-structured telephone interviews with 29 women who had participated in the RCT were conducted. The transcribed interviews were then thematically analysed. RESULTS: Most of the women were dissatisfied with how they normally produced urine samples. Many were able to use the devices, found them hygienic, and would use them again, even if they had initially experienced problems. Women who had not used the devices expressed interest in trying them. Potential barriers to UCD use included positioning for the sample, UTI symptoms making urine collection difficult, and waste disposal because of the single-use plastic in the UCDs. CONCLUSION: Most women agreed there was a need for a user- and environmentally-friendly device to improve urine collection. Although using UCDs can be difficult for women experiencing UTI symptoms, they may be appropriate for asymptomatic sampling in other clinical populations.

Clean-Catch Urine Specimen More Likely to Be Contaminated After Vaginal Surgery for Pelvic Organ Prolapse.

IMPORTANCE: Accurate diagnosis of urinary tract infection after pelvic organ prolapse (POP) surgery is essential to postoperative care. OBJECTIVE: Our aim was to determine the agreement between the urinalysis of a clean-catch versus a straight catheter urine specimen in women who underwent vaginal surgery for POP. STUDY DESIGN: This was a cross-sectional study evaluating patients after vaginal surgery for POP. A clean-catch and straight catheter urine specimen were collected at routine postoperative appointments. Routine urinalyses and urine cultures were performed for all patients. A urine culture yielding mixed urogenital flora (which includes Lactobacillus species), coagulase-negative staphylococci, and Streptococcus species was considered a contaminated result. The agreement between the characteristics of urinalysis obtained via the clean catch versus the straight catheter at 3 weeks postoperatively was evaluated using weighted κ statistic. RESULTS: Fifty-nine participants enrolled. The agreement between the characteristics of urinalysis obtained via the clean catch versus the straight catheter was poor (κ = 0.018). The urine culture was more likely to be contaminated from the clean-catch urine specimen than from the straight catheter urine specimen (53.7% vs 23.1%).The positive and negative predictive values of leukocyte esterase on clean catch were 22.6% and 100%, respectively. CONCLUSIONS: Diagnosing urinary tract infection based on contaminated urinalyses may lead to antibiotic overuse and misdiagnosis of postoperative complications. Our results can help educate health care partners and discourage the use of clean-catch urine specimens when assessing women who have recently undergone vaginal surgery.

Urinary Sucrose and Fructose From Spot Urine May Be Used as a Predictive Biomarker of Total Sugar Intake-Findings From a Controlled Feeding Study.

BACKGROUND: Recently, we confirmed 24-h urinary sucrose plus fructose (24 uSF) as a predictive biomarker of total sugar intake. However, the collection of 24-h urine samples has limited feasibility in population studies. OBJECTIVE: We investigated the utility of the urinary sucrose plus fructose (uSF) biomarker measured in spot urine as a measure of 24 uSF biomarker and total sugar intake. METHODS: Hundred participants, 18-70 y of age, from the Phoenix Metropolitan Area completed a 15-d feeding study. For 2 of the 8 collected 24-h urine samples, each spot urine sample was collected in a separate container. We considered 4 timed voids of the day [morning (AM) void: first void 08:30-12:30; afternoon (PM) void: first void 12:31-17:30; evening (EVE) void: first void 17:31-12:00; and next-day (ND) void: first void 04:00-12:00]. We investigated the performance of uSF from 1 void, and uSF combined from 2 and 3 voids as a measure of 24 uSF and sugar intake. RESULTS: The biomarker averaged from PM/EVE void strongly correlated with 24 uSF (partial r = 0.75). The 24 uSF predicted from the PM/EVE combination was significantly associated with observed sugar intake and was selected for building the calibrated biomarker equation (marginal R2 = 0.36). Spot urine-based calibrated biomarker, ie, biomarker-estimated sugar intake was moderately correlated with the 15-d mean-observed sugar intake (r = 0.50). CONCLUSIONS: uSF measured from a PM and EVE void may be used to generate biomarker-based sugar intake estimate when collecting 24-h urine samples is not feasible, pending external validation.

The impact of urine collection method on canine urinary microbiota detection: a cross-sectional study.

BACKGROUND: The urinary tract harbors unique microbial communities that play important roles in urogenital health and disease. Dogs naturally suffer from several of the same urological disorders as humans (e.g., urinary tract infections, neoplasia, urolithiasis) and represent a valuable translational model for studying the role of urinary microbiota in various disease states. Urine collection technique represents a critical component of urinary microbiota research study design. However, the impact of collection method on the characterization of the canine urinary microbiota remains unknown. Therefore, the objective of this study was to determine whether urine collection technique alters the microbial populations detected in canine urine samples. Urine was collected from asymptomatic dogs by both cystocentesis and midstream voiding. Microbial DNA was isolated from each sample and submitted for amplicon sequencing of the V4 region of the bacterial 16 S rRNA gene, followed by analyses to compare microbial diversity and composition between urine collection techniques. RESULTS: Samples collected via midstream voiding exhibited significantly higher sequence read counts (P = .036) and observed richness (P = .0024) than cystocentesis urine. Bray Curtis and Unweighted UniFrac measures of beta diversity showed distinct differences in microbial composition by collection method (P = .0050, R2 = 0.06 and P = .010, R2 = 0.07, respectively). Seven taxa were identified as differentially abundant between groups. Pasteurellaceae, Haemophilus, Friedmanniella, two variants of Streptococcus, and Fusobacterium were over-represented in voided urine, while a greater abundance of Burkholderia-Caballeronia-Paraburkholderia characterized cystocentesis samples. Analyses were performed at five thresholds for minimum sequence depth and using three data normalization strategies to validate results; patterns of alpha and beta diversity remained consistent regardless of minimum read count requirements or normalization method. CONCLUSION: Microbial composition differs in canine urine samples collected via cystocentesis as compared to those collected via midstream voiding. Future researchers should select a single urine collection method based on the biological question of interest when designing canine urinary microbiota studies. Additionally, the authors suggest caution when interpreting results across studies that did not utilize identical urine collection methods.

Temperature and time after urine collection affect the detection of phenethylamine, a substance prohibited in sports.

2-Phenylethylamine (phenethylamine) and its derivatives are stimulant drugs, which are prohibited in sports because of their potential performance-enhancing properties. If phenethylamine is detected in an athlete's urine, the athlete may be subjected to serious sanctions, such as disqualification for both domestic and international competitions. Given the serious consequences athletes face for phenethylamine detection, great care should be taken to avoid false positive tests. In forensic medicine, it is widely known that phenethylamine is produced by putrefactive bacteria in autopsy urine samples; it is possible that this process could also occur in an athlete's urine sample without proper storage. In this study, human urine samples were stored at -20, 4, or 22°C for 14 days, and phenethylamine in the samples was quantitatively analyzed using ultra-high-performance liquid chromatography-tandem mass spectrometry. No phenethylamine was detected in urine samples stored at -20°C throughout 14-day period. Nevertheless, phenethylamine was detected after 6 days in these samples stored at 4°C and after only 1 day in samples stored at 22°C. Additionally, the concentration of phenethylamine in these samples increased each day after detection. These results suggest that urine samples should be stored immediately at -20°C after collection when testing athletes for phenethylamine, especially if the sample must be stored for extended period before testing.

Variability of 24-Hour Sodium Urinary Excretion in Young Healthy Males Based on Consecutive Urine Collections: Impact on Categorization of Salt Intake.

OBJECTIVE: Several nonconsecutive 24-h urinary collections are considered the gold standard for estimating dietary salt intake. As those samples are logistically demanding, we aimed to describe the variability of 24-h sodium urinary excretion over consecutive days and report its adequacy with sodium intake. METHODS: We enrolled 16 healthy male volunteers in a prospective controlled study. All participants randomly received a low salt diet (LSD) (3 g/day of NaCl), a normal salt diet (NSD) (6 g/day of NaCl), and a high salt diet (HSD) (15 g/day of NaCl) for 7 days in a crossover design without wash-out period. RESULTS: On day 6, median sodium urinary excretion was 258 (216-338), 10 (8-18), and 87 (69-121) mmol/day for HSD, LSD, and NSD, respectively (P < .001). When considering days 4-6, sodium urinary excretion was in steady state as models with and without interaction term "diet type X sample day" were not significantly different (P = .163). On day 6, area under the curve (AUC) of receiver operating characteristic for urinary sodium excretion to detect HSD was 1.0 (1.0-1.0) and a cut-point of 175 mmol/day was 100% sensitive and specific to detect HSD. On day 6, receiver operating characteristic AUC to detect LSD was 0.993 (0.978-1.0) and a cut-point of 53 mmol/day was 96.4% sensitive and 100% specific to detect LSD. CONCLUSION: A steady state of sodium balance, where sodium intake is proportional to its excretion, is reached within a few days under a constant diet in the real-life setting. Categorization of salt consumption into low (3 g/day), normal (6 g/day), or high (15 g/day) based on a single 24-h urine collection is nearly perfect. Based on these results, repeated nonconsecutive urine collection might prove unnecessary to estimate sodium intake in daily clinical practice provided that diet is rather constant over time.

Estimating mean population salt intake using spot urine samples in Nepal: a cross-sectional study.

INTRODUCTION: Little is known about the usefulness of spot urine testing compared with 24-h urine samples to estimate salt intake in low-income settings. This is given 24-h urinary collection can be costly, burdensome, and impractical in population surveys. The primary objective of the study was to compare urinary sodium levels (as an estimate of salt intake) of Nepalese population between 24-h urine and spot urine using previously established spot urine-based equations. Additionally, this study explored the 24-h prediction of creatinine and potassium excretion from spot urine samples using available prediction equations. METHODS: The sample population was derived from the community-based survey conducted in Nepal in 2018. Mean salt intake was estimated from spot urine samples comparing previously published equations, and this was then contrasted with mean salt intake estimations from 24-h urine samples, using paired t test, Pearson correlation coefficient, intraclass correlation coefficient, and Bland-Altman plots. RESULTS: A total of 451 participants provided both complete 24-h and morning spot urine samples. Unweighted mean (±SD) salt intake based on 24-h urine collection was 13.28 ±â€Š4.72 g/day. The corresponding estimates were 15.44 ±â€Š5.92 g/day for the Kawasaki, 11.06 ±â€Š3.17 g/day for the Tanaka, 15.22 ±â€Š16.72 g/day for the Mage, 10.66 ±â€Š3.35 g/day for the Toft, 8.57 ±â€Š1.72 g/day for the INTERSALT with potassium, 8.51 ±â€Š1.73 g/day for the INTERSALT without potassium, 7.88 ±â€Š1.94 g/day for the Whitton, 18.13 ±â€Š19.92 g/day for the Uechi simple-mean and 12.07 ±â€Š1.77 g/day using the Uechi regression. As compared with 24-h urine estimates, all equations showed significant mean differences (biases); the Uechi regression had the least difference with 9% underestimation (-1.21 g/day, P  < 0.001).Proportional biases were evident for all equations depending on the level of salt intake in the Bland-Altman plots. CONCLUSION: None of the included spot urine-based equations accurately corresponded to 24-h salt intake in the present study. These equations may be useful for longitudinal monitoring of population salt intake in Nepal, our study highlights that there are limitations on using existing equations for estimating mean salt intake in Nepali population. Further studies are warranted for accuracy and validation.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review.

INTRODUCTION: To evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. METHODS: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. RESULTS: Only two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. CONCLUSIONS: More studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Best methods for urine sample collection for diagnostic accuracy in women with urinary tract infection symptoms: a systematic review.

BACKGROUND: Most guidelines recommend a midstream urine (MSU) or a midstream clean-catch (MSCC) sample for urinalysis. However, whether this sample is better than others is still controversial. OBJECTIVES: To assess the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections (UTI) in symptomatic non-pregnant women. METHODS: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched paired sample studies and controlled trials. Studies comparing MSCC, MSU without cleaning, first-void urine, and random voiding samples were considered. Studies evaluating invasive methods were excluded. The main outcome was diagnostic accuracy of urine cultures. Contamination rates were evaluated. The risk of bias tool for systematic reviews on diagnostic accuracy (QUADAS-2) was assessed. RESULTS: Six studies including 1,010 patients were evaluated. Only two studies used paired samples. No study was considered as having low risk of bias. There was no difference in contamination for MSU specimens collected with or without cleansing and between random void urine collection and MSCC. In one study comparing first-void urine with MSU samples, the contamination rate was lower in the latter, but the gold standard of urine culture was only used for one sampling collection. CONCLUSIONS: To the best of our knowledge, this systematic review is the first to assess the evidence available from different exclusively non-invasive urine sampling. Despite being widely recommended, our review did not find consistent evidence that asking women to provide midstream samples with or without cleansing is better.

Urine is one type of specimen that can be easily collected from a patient. Urinalysis testing can give the doctor valuable information about the presence of an infection in the urine and the type of microorganism causing this infection. The physician can also use the information from urine testing to diagnose and treat other diseases. The collection of the mid-stream of the urination has always been advocated. However, this recommendation has never been proven with good quality studies, and the results of the studies carried out so far have been controversial. In a systematic review, we recently determined that the use of any specimen during urination is as good as midstream collection when patients are requested to provide a urine sample and in terms of quality even specimens collected without proper cleansing are also comparable to mid-stream collection with cleansing. In the present systematic review, we evaluated the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections in symptomatic non-pregnant women. We identified only six studies comparing different urine sampling techniques and we did not observe any difference regarding the quality of the urine between them.