An Italian external quality assessment (EQA) program on urinary sediment

Establishing an External Quality Assessment (EQA) Program for Urinalysis in Medical Laboratories of Thailand

Thailand Association of Clinical Biochemists (TACB) introduced External Quality Assurance schemes (EQAs) for urinalysis (UA) using urine strips in medical laboratories of Thailand. The few available External Quality Assessment (EQA) programs on urinary microalbumin rarely include an evaluation of clinical cases. The aim of the present study was to assess a descriptive analysis of biochemical urinalysis including urine microalbumin in the Thailand laboratory practice. From January 2021 to December 2021, four surveys were organized. EQA urine samples were distributed to the participants by mail. The participants measured the UA of 2 samples quarterly and returned the results together with the information about their instruments and suggestion for the performance of the laboratory report quarterly. Moreover, summary of the situation of each laboratory performance was feedbacked by online system. Fifty-eight laboratories participated in the survey. The EQA panels included positive and negative samples. The analytical results for passed parameters of urine chemical test range from 79.3-100%. All special tests; microalbumin, creatinine, and beta-HCG showed correct result from 85.1-96.1%. The overall accuracy, specificity, and sensitivity were 92.6, 85.7, and 75,4%, respectively. The major issues were observed: the low sensitivity for the detection of low-concentration samples and the incapacity of several methods to detect the positive sample. The assessment is needed to continuously evaluate the improvement proficiency of laboratories in Thailand.

Survey on reporting of epithelial cells in urine sediment as part of external quality assessment programs in Brazilian laboratories

Introduction

Epithelial cells (ECs) are structures regularly observed during urine microscopy analysis. The correct identification of EC subtypes can be useful since renal tubular epithelial cells (RTECs) are clinically relevant. We investigate the urinary ECs report and the judgement of its clinical importance by Brazilian laboratories.

Materials and methods

A survey with four questions was made available to participants of the Urinalysis External Quality Assessment Program (EQAP) from Controllab. Laboratories composed 3 groups: (1) differentiating ECs subtypes: “squamous”, “transitional” and “RTECs”; (2) differentiating ECs subtypes: “squamous” or “non-squamous” cells; (3) without ECs subtype identification. Participants did not necessarily answer to all questions and the answers were evaluated both within the same laboratory’s category and within different categories of laboratories.

Results

A total of 1336 (94%) laboratories answered the survey; Group 1, 119/140 (85%) reported that ECs differentiation is important to the physician and 62% want to be evaluated by EQAP, while in Group 3, 455/1110 (41%) reported it is useful to them, however only 25% want be evaluated by EQAP. Group 2 laboratories 37/51 (73%) reported that the information is important, but only 13/52 (25%) are interested in an EQAP with differentiation of the 3 ECs subtypes.

Conclusion

Most of the laboratories do not differentiate ECs in the three subtypes, despite the clinical importance of RTECs. Education of laboratory staff about the clinical significance of urinary particles should be considered a key priority.

The Italian External Quality Assessment (EQA) program on urinary sediment by microscopy examination: a 20 years journey

OBJECTIVES

In spite of the introduction of automated systems for urinary sediment analysis, microscopy examination remains the gold standard, and it is more than ever important to perform it with a good and reliable quality. External Quality Assessment (EQA) programs on urinary sediment are rare. The present paper provides an analysis of results from 2001 to date of the EQA Italian program which involves today 230 laboratories.

METHODS

The program includes four surveys per year. Participants are asked the identification and clinical associations of urinary sediment particles, shown as phase contrast microscopy images in the website of the Center of Biomedical Research (CRB) (2 surveys), and the diagnosis of clinical cases presented by both images and a short clinical history (2 surveys). The results of each survey are then scored and commented. In 20 years, 298 images were presented: 90 cells (9 types), 23 lipids (5 types), 87 casts (21 types), 53 crystals (14 types), 22 microorganisms (5 types), and 23 contaminants (9 types). Moreover, 27 clinical cases, covering a wide spectrum of conditions with different degrees of complexity, were presented to participants.

RESULTS

Identification: among urinary particle categories, the correct identification rate (obtained for each particle from the sum of correct + partially correct answers) was very high for micro-organisms (mean ± SD: 96.2 ± 3.5%), high for lipids (88.0 ± 11.8%) and crystals (87.0 ± 16.5%) followed, in decreasing order, by cells (82.1 ± 15.9%), casts (81.8 ± 14.8%), and contaminants (76.7 ± 22.1%). Clinical associations (n=67): the rate of correct answers was 93.5 ± 5.7% ranging from 75.0 to 100% for all but one clinical association (i.e., acute glomerulonephritis: 55.4%). Clinical cases: throughout surveys, due to the overall rate of particle misidentification, only 59.8 ± 17.1%, (range 32.5-88.7%) of participants achieved access to clinical diagnosis. Of these, 88.7 ± 10.6% (range 59.9-99.3%) were able to indicate the correct diagnosis.

CONCLUSIONS

Our program can be used as a tool to improve the identification of urine particles and the knowledge of their clinical meaning and to encourage specialists of laboratory medicine to correlate urinary findings with other laboratory data and the clinical history, an aspect that improves the value of the day by day work.

Current state of the morphological assessment of urinary erythrocytes in The Netherlands: a nation-wide questionnaire

Background The morphological assessment of urinary erythrocytes (uRBC) is a convenient screening tool for the differentiation of nephrological (dysmorphic) and urological (isomorphic) causes of hematuria. Considering the morphological heterogeneity, this analysis is often perceived as difficult. There is no clear (inter)national consensus and there is a lack of external quality assessment programs. To gain insight into the heterogeneity within and between laboratories, we scrutinized the current state of this analysis in Dutch medical laboratories. Methods The laboratories, affiliated with the Dutch Foundation for Quality Assessment in Medical Laboratories, were invited to participate in a web-based survey, consisting of two questionnaires. The first one provided information about the institution and laboratory organization, and the second explored the variability in the morphological analysis of uRBC on the basis of categorization of 160 uRBC images. Statistical analysis was premised on binomial significance testing and principal component analysis. Results Nearly one third of the Dutch medical laboratories (65/191) with 167 staff members participated in the survey. Most of these laboratories (83%) were an integral part of secondary care. The statistical analysis of the evaluations of the participants in comparison to the consensus (three experts from two different medical laboratories) suggested a great degree of heterogeneity in the agreement. Nearly half of the participants consciously disagreed with the consensus, whereas one fifth demonstrated a random relationship with it. Conclusions In Dutch medical laboratories, results from morphological analysis of uRBC are heterogeneous, which point out the necessity for standardization and harmonization.

Assessment of Interobserver Reliability of Nephrologist Examination of Urine Sediment

IMPORTANCE

Urine sediment microscopy is commonly performed during the evaluation of kidney disease. Interobserver reliability of nephrologists' urine sediment examination has not been well studied.

OBJECTIVE

Assess interobserver reliability of the urine sediment examination.

DESIGN, SETTING, AND PARTICIPANTS

In this diagnostic test study, urine samples were prospectively collected from a convenience sample of adult patients from an academic hospital in the United States undergoing kidney biopsy from July 11, 2018, to March 20, 2019. Digital images and videos of urine sediment findings were captured using a bright-field microscope. These images and videos along with urine dipstick results were incorporated in online surveys and sent to expert nephrologists at 15 US teaching hospitals. They were asked to identify individual sediment findings and the most likely underlying disease process.

EXPOSURES

Urine dipstick results and urine sediment images from patients undergoing native kidney biopsy.

MAIN OUTCOMES AND MEASURES

Interobserver reliability of urine sediment microscopy findings estimated by overall percent agreement and Fleiss κ coefficients. Secondary outcomes included concordance of diagnoses suspected by nephrologists with corresponding kidney biopsy results.

RESULTS

In total, 10 surveys from 10 patients containing 76 study questions on individual features were sent to 21 nephrologists, 14 (67%) of whom completed them all. Their combined 1064 responses were analyzed. Overall percent agreement for casts was an estimated 59% (95% CI, 50%-69%), κ = 0.52 (95% CI, 0.42-0.62). For other sediment findings, overall percent agreement was an estimated 69% (95% CI, 61%-77%), κ = 0.65 (95% CI, 0.56-0.73). The κ estimates ranged from 0.13 (95% CI, 0.10-0.17) for mixed cellular casts to 0.90 (95% CI, 0.87-0.94) for squamous epithelial cells.

CONCLUSIONS AND RELEVANCE

In this study, substantial variability occurred in the interpretation of urine sediment findings, even among expert nephrologists. Educational or technological innovations may help improve the urine sediment as a diagnostic tool.

Establishment of a reference procedure to measure urine-formed elements and evaluation of an automated urine analyzer

A standardized reference method is needed to accurately and precisely measure urine-formed elements (UFEs; red blood cells [RBCs], white blood cells [WBCs], and squamous epithelial cells [sECs]). We compared the results from a standard method with those from an automated analyzer. Trained technicians used standardized bright-field microscopy of fresh non-centrifuged urine samples, and disposable 1 µl chambers. Fifteen experienced technicians from 5 hospitals (3 per hospital) each performed 6 manual counts of 10 different native urine samples using a manual chamber and standard methods. The sEC counts were at least 50/µL, and the coefficient of variation (CV) was less than 14%; the RBC and WBC counts were at least 200/µL and the CVs were less than 7%. The same samples were also analyzed 6 times using automated analyzers. The means, CVs, and biases were determined. The median CVs for the manual measurements were 6.4% (WBCs), 6.6% (RBCs), and 12.7% (sECs). The CVs of the automated analyzer were 4.7% (WBCs), 5.6% (RBCs), and 9.2% (sECs). Biases between the automated and manual methods were -2.9% to 5.0%(WBCs), -0.8% to 8.8% (RBCs) and -2.8% to 9.4% (sECs). The count mean values and expanded uncertainties of these counts were (224.5 ± 15.0) cells/µL, (234.2 ± 16.2) cells/µL, and (61.5 ± 7.9) cells/µL, respectively. The standardized manual method for measuring UFEs had high precision and accuracy, making it a suitable reference method. Use of this reference method to calibrate an automated analyzer improved the accuracy of automated analysis.

Extra-analytical quality indicators – where to now?

A large body of evidence collected in recent years demonstrates the vulnerability of the extra-analytical phases of the total testing process (TTP) and the need to promote quality and harmonization in each and every step of the testing cycle. Quality indicators (QIs), which play a key role in documenting and improving quality in TTP, are essential requirements for clinical laboratory accreditation. In the last few years, wide consensus has been achieved on the need to adopt universal QIs and common terminology and to harmonize the management procedure concerning their use by adopting a common metric and reporting system. This, in turn, has led to the definition of performance specifications for extra-analytical phases based on the state of the art as indicated by data collected on QIs, particularly by clinical laboratories attending the Model of Quality Indicators program launched by the Working Group “Laboratory Errors and Patient Safety” of the International Federation of Clinical Chemistry and Laboratory Medicine. Harmonization plays a fundamental role defining not only the list of QIs to use but also performance specifications based on the state of the art, thus providing a valuable interlaboratory benchmark and tools for continuous improvement programs.