Postanalytical External Quality Assessment of Urine Albumin in Primary Health Care: An International Survey

Diagnostic challenges of diabetic kidney disease

Diabetic kidney disease (DKD) is one of the most common microvascular complications of both type 1 and type 2 diabetes and the most common cause of the end-stage renal disease (ESRD). It has been evidenced that targeted interventions at an early stage of DKD can efficiently prevent or delay the progression of kidney failure and improve patient outcomes. Therefore, regular screening for DKD has become one of the fundamental principles of diabetes care. Long-established biomarkers such as serum-creatinine-based estimates of glomerular filtration rate and albuminuria are currently the cornerstone of diagnosis and risk stratification in routine clinical practice. However, their immanent biological limitations and analytical variations may influence the clinical interpretation of the results. Recently proposed new predictive equations without the variable of race, together with the evidence on better accuracy of combined serum creatinine and cystatin C equations, and both race- and sex-free cystatin C-based equation, have enabled an improvement in the detection of DKD, but also require the harmonization of the recommended laboratory tests, wider availability of cystatin C testing and specific approach in various populations. Considering the complex pathophysiology of DKD, particularly in type 2 diabetes, a panel of biomarkers is needed to classify patients in terms of the rate of disease progression and/or response to specific interventions. With a personalized approach to diagnosis and treatment, in the future, it will be possible to respond to DKD better and enable improved outcomes for numerous patients worldwide.

Informatics External Quality Assurance (IEQA) Down Under: evaluation of a pilot implementation

External quality assurance (EQA) provides ongoing evaluation to verify that laboratory medicine results conform to quality standards expected for patient care. While attention has focused predominantly on test accuracy, the diagnostic phases, consisting of pre- and post-laboratory phases of testing, have thus far lagged in the development of an appropriate diagnostic-phase EQA program. One of the challenges faced by Australian EQA has been a lack of standardisation or “harmonisation” resulting from variations in reporting between different laboratory medicine providers. This may introduce interpretation errors and misunderstanding of results by clinicians, resulting in a threat to patient safety. While initiatives such as the Australian Pathology Information, Terminology and Units Standardisation (PITUS) program have produced Standards for Pathology Informatics in Australia (SPIA), conformity to these requires regular monitoring to maintain integrity of data between sending (laboratory medicine providers) and receiving (physicians, MyHealth Record, registries) organisations’ systems. The PITUS 16 Informatics EQA (IEQA) Project together with the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) has created a system to perform quality assurance on the electronic laboratory message when the laboratory sends a result back to the EQA provider. The purpose of this study was to perform a small scale pilot implementation of an IEQA protocol, which was performed to test the suitability of the system to check compliance of existing Health Level-7 (HL7 v2.4) reporting standards localised and constrained by the RCPA SPIA. Here, we present key milestones from the implementation, including: (1) software development, (2) installation, and verification of the system and communication services, (3) implementation of the IEQA program and compliance testing of the received HL7 v2.4 report messages, (4) compilation of a draft Informatics Program Survey Report for each laboratory and (5) review consisting of presentation of a report showing the compliance checking tool to each participating laboratory.

External Quality Assessment beyond the analytical phase: an Australian perspective

External Quality Assessment (EQA) is the verification, on a recurring basis, that laboratory results conform to expectations for the quality required for patient care. It is now widely recognised that both the pre- and post-laboratory phase of testing, termed the diagnostic phases, are a significant source of laboratory errors. These errors have a direct impact on both the effectiveness of the laboratory and patient safety. Despite this, Australian laboratories tend to be focussed on very narrow concepts of EQA, primarily surrounding test accuracy, with little in the way of EQA programs for the diagnostic phases. There is a wide range of possibilities for the development of EQA for the diagnostic phases in Australia, such as the utilisation of scenarios and health informatics. Such programs can also be supported through advances in health information and communications technology, including electronic test ordering and clinical decision support systems. While the development of such programs will require consultation and support from the referring doctors, and their format will need careful construction to ensure that the data collected is de-identified and provides education as well as useful and informative data, we believe that there is high value in the development of such programs. Therefore, it is our opinion that all pathology laboratories should strive to be involved in an EQA program in the diagnostic phases to both monitor the diagnostic process and to identify, learn from and reduce errors and near misses in these phases in a timely fashion.

How well do general practitioners manage laboratory test results for patients with diabetes mellitus and cardiovascular disease?: A systematic review

Purpose

To evaluate how well general practitioners (GPs) manage and respond to laboratory results for patients with diabetes mellitus (DM) and cardiovascular disease (CVD).

Data sources

MEDLINE, CINAHL, Embase, EBM reviews, ProQuest and Scopus.

Study selection

Peer-reviewed journal articles published between 2000 and 2015 that assessed GPs' management of laboratory results for patients with DM or CVD.

Data extraction

Study design and demographics, laboratory tests and key findings relating to GP management of laboratory results were extracted from studies.

Results of data synthesis

Thirteen articles were included, comprising seven studies which utilized surveys, four observational studies, one cohort study and one randomized controlled trial. Findings indicate that GPs often overestimate the risk of complications associated with DM and CVD based on laboratory results and have unrealistically high expectations regarding the precision of laboratory tests. Considerable variation existed in the use of repeat testing for diagnostic confirmation and in GPs' identification of the difference between two consecutive results required to indicate a change in patient condition. GPs also often failed to initiate appropriate treatment for patients with DM and CVD based on laboratory results. Feedback to GPs about their test ordering patterns and educational messages on laboratory results improved clinical outcomes.

Conclusion

Evidence about how well GPs manage results and its impact on patient outcomes remains weak and inconclusive. This review identified a number of areas where interventions could support GPs to improve the interpretation and management of laboratory test results, including feedback to GPs and educational messages on test result reports.

Analytical performance specifications based on how clinicians use laboratory tests. Experiences from a post-analytical external quality assessment programme

Analytical performance specifications can be based on three different models: the effect of analytical performance on clinical outcome, based on components of biological variation of the measurand or based on state-of-the-art. Models 1 and 3 may to some degree be combined by using case histories presented to a large number of clinicians. The Norwegian Quality Improvement of Primary Care Laboratories (Noklus) has integrated vignettes in its external quality assessment programme since 1991, focusing on typical clinical situations in primary care. Haemoglobin, erythrocyte sedimentation rate (ESR), HbA1c, glucose, u-albumin, creatinine/estimated glomerular filtration rate (eGFR), and Internationl Normalised Ratio (INR) have been evaluated focusing on critical differences in test results, i.e., a change from a previous result that will generate an "action" such as a change in treatment or follow-up of the patient. These critical differences, stated by physicians, can translate into reference change values (RCVs) and assumed analytical performance can be calculated. In general, assessments of RCVs and therefore performance specifications vary both within and between groups of doctors, but with no or minor differences regarding specialisation, age or sex of the general practitioner. In some instances state-of-the-art analytical performance could not meet clinical demands using 95% confidence, whereas clinical demands were met using 80% confidence in nearly all instances. RCVs from vignettes should probably not be used on their own as a basis for setting analytical performance specifications, since clinicians seem "uninformed" regarding important principles. They could rather be used as a background for focus groups of "informed" physicians in discussions of performance specifications tailored to "typical" clinical situations.

Albuminuria: Prevalence, associated risk factors and relationship with cardiovascular disease

AIMS/INTRODUCTION

To investigate the prevalence and associated risk factors of microalbuminuria, and to explore the relationship between albuminuria and cardiovascular disease (CVD).

MATERIALS AND METHODS

A nationally representative sample of 38,203 Chinese participants was categorized by different levels of urinary albumin-to-creatinine ratio (ACR; 0 -10 mg/g, 10 -20 mg/g, 20 -30 mg/g, 30 -300 mg/g). The prevalence of albuminuria was compared by using a single urinary ACR cut-off point and by sex-specific ACR cut-off points. Factors associated with the presence of albuminuria, and the relationship between albuminuria and CVD were analyzed by logistic regression.

RESULTS

Prevalence of albuminuria as measured by a single ACR cut-point was significantly lower for men compared with women (13.9% vs 19.1% in the normal glucose tolerance group; 20.8% vs 26.8% in the impaired glucose tolerance group, P < 0.01). The prevalence of albuminuria, as measured by sex-specific ACR cut-points, was higher for men than women (31.4% vs 29.6% in the normal glucose tolerance group; 42.2% vs 39.3% in the impaired glucose tolerance group, P < 0.01). The independent risk factors for the presence of albuminuria were aging, female sex, hypertension, hyperglycemia, obesity, dyslipidemia, insulin resistance and metabolic syndrome. The subdivided normal ACR group did not show a linear or statistically significant relationship with CVD after adjusting for conventional CVD risk factors (P > 0.05).

CONCLUSIONS

The prevalence of albuminuria was high in the general Chinese population. Aging, female sex, hypertension, hyperglycemia, dyslipidemia, insulin resistance, obesity and metabolic syndrome were all independent risk factors for albuminuria. The causal relationship between ACR and CVD might require further follow-up investigation.

Critical review of laboratory investigations in clinical practice guidelines: proposals for the description of investigation

BACKGROUND

Correct information provided by guidelines may reduce laboratory test related errors during the pre-analytical, analytical and post-analytical phase and increase the quality of laboratory results.

METHODS

Twelve clinical practice guidelines were reviewed regarding inclusion of important laboratory investigations. Based on the results and the authors' experience, two checklists were developed: one comprehensive list including topics that authors of guidelines may consider and one consisting of minimal standards that should be covered for all laboratory tests recommended in clinical practice guidelines. The number of topics addressed by the guidelines was related to involvement of laboratory medicine specialists in the guideline development process.

RESULTS

The comprehensive list suggests 33 pre- analytical, 37 analytical and 10 post-analytical items. The mean percentage of topics dealt with by the guidelines was 33% (median 30%, range 17%-55%) and inclusion of a laboratory medicine specialist in the guideline committee significantly increased the number of topics addressed. Information about patient status, biological and analytical interferences and sample handling were scarce in most guidelines even if the inclusion of a laboratory medicine specialist in the development process seemingly led to increased focus on, e.g., sample type, sample handling and analytical variation. Examples underlining the importance of including laboratory items are given.

CONCLUSIONS

Inclusion of laboratory medicine specialist in the guideline development process may increase the focus on important laboratory related items even if this information is usually limited. Two checklists are suggested to help guideline developers to cover all important topics related to laboratory testing.

Albuminuria prevalence in first morning void compared with previous random urine from adults in the National Health and Nutrition Examination Survey, 2009-2010

BACKGROUND

Albuminuria, defined as urine albumin/creatinine ratio (ACR) ≥30 mg/g, is a diagnostic component of chronic kidney disease (CKD). National estimates of ACR and CKD prevalence have been based on single random urine samples. Although 2 urine samples or a first morning void are known to produce different estimates of ACR, the impact of differing urine sampling schemes on nationally estimated rates of CKD is unknown.

METHODS

In 2009-2010, the National Health and Nutrition Examination Survey (NHANES) participants provided 2 untimed urine samples for sequential ACR measurement: an initial random urine collected in the NHANES mobile examination center and a subsequent first morning void collected at home. Rates of albuminuria were calculated in the overall population and broken down by demographics, diagnosed diabetes and hypertension status, and estimated glomerular filtration rate (eGFR).

RESULTS

Overall, 43.5% of adults with increased ACR (≥30 mg/g) in a random urine also had increased ACR in a first morning urine. This percentage was higher among individuals ≥50 years old (48.9%), males (53.3%), participants with diagnosed diabetes (56.3%) and hypertension (51.5%), and eGFR <60 mL/min/1.72m(2) (56.9%). The use of confirmed increased ACR (defined as the presence of ACR ≥30 mg/g in both samples taken within 10 days) to define CKD resulted in a lower overall prevalence (11.6%) than first morning urine (12.7%) or random spot urine only (15.2%).

CONCLUSIONS

ACR measured on random urine samples appears to overestimate the prevalence of albuminuria compared to first morning urine collections.

How do laboratory specialists advise clinicians concerning the use and interpretation of renal tests?

BACKGROUND

The aim of this study was to elucidate how laboratory specialists advise clinicians concerning renal parameters and to compare their advice with guideline recommendations.

METHODS

A questionnaire was distributed to laboratory specialists in Norway and The Netherlands together with two case histories from a primary health-care setting and one from a hospital setting, simulating questions from clinicians. The investigations that laboratory specialists suggested were compared to a test panel that was predefined based on clinical practice guideline recommendations (the 'recommended test panel'). The critical differences between two test results (creatinine, estimated glomerular filtration rate [eGFR] and albumin/creatinine ratio [ACR]) and the anticipated precision of the MDRD equation were evaluated.

RESULTS

Fifty-two of the 100 laboratory specialists responded, and most of these were regularly contacted by clinicians to discuss laboratory results. Less than 30% would suggest using the recommended test panel to evaluate renal function in the two primary-care patients. For creatinine and eGFR, median changes stated to signal improvement or deterioration in renal function (creatinine: -14% and +14%, respectively; eGFR: +18% and -13%, respectively) were similar to what could be calculated using information on analytical and within-subject variation from the literature. There were variable critical differences for the ACR results (median values of -50% for improvement and +67% for deterioration). Only 23% of the participants would recommend a gold standard clearance examination for a patient who was to undergo nephrotoxic chemotherapy.

CONCLUSION

Questions from GPs about renal parameters are answered differently by laboratory specialists, and adherences to guideline recommendations are low on some issues.

Diagnosing microalbuminuria and consequences for the drug treatment of patients with type 2 diabetes: a European survey in primary care

AIMS

To assess general practitioners (GPs) knowledge of guideline recommendations on diagnosing microalbuminuria (MA) and to evaluate how this diagnosis influences drug treatment of diabetes patients.

METHODS

A postal case-history based questionnaire describing a male patient (previously not tested for MA) with type 2 diabetes who had several risk markers for cardiovascular disease.

RESULTS

2078GPs from nine European countries were included, with response rates varying from 7% to 43%. Almost all GPs recommended annual testing for MA. Forty-five to 77% (depending on country) of GPs required more than one positive test to diagnose MA. The absolute increase in the percentages of GPs who would supplement the patient's drug treatment if MA developed was: for anginotensin converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) 23-50% (depending on country), for statins 0-19%, for acetylsalicylic acid 2-13%, and for hypoglycemic agents (tablets and insulin) 0-33%. The proportion of GPs recommending all four possible treatment modalities was low.

CONCLUSIONS

Guidelines for diagnosing MA were partly followed. ACEIs and ARBs were recommended when MA was present, but the recommended multifactorial treatment of cardiovascular risk markers was not implemented.

Comparison of different measures of urinary protein excretion for prediction of renal events

There are many methods to screen for abnormal amounts of proteinuria to identify patients at risk for progression of renal disease, but which method best predicts renal risk is unknown. Here, we analyzed a subset of 701 patients with type 2 diabetes and nephropathy participating in the Reduction of Endpoints in Non Insulin Dependent Diabetes Mellitus with the Angiotensin II Antagonist Losartan (RENAAL) trial to compare the ability of urinary protein excretion (UPE) and urinary albumin excretion (UAE) from a 24-hour urine collection and urinary albumin concentration (UAC) and the albumin:creatinine ratio (ACR) from a first-morning void in predicting renal events. The primary outcome measure was the time to a doubling of serum creatinine or end-stage renal disease. During follow-up, 202 events occurred. The hazard ratios for the risk of a renal outcome (95% CIs) associated with 1-SD increment in the log-transformed measures were 3.16 (2.60 to 3.86) for UAE, 3.02 (2.53 to 3.62) for UPE, 3.23 (2.67 to 3.91) for UAC, and 4.36 (3.50 to 5.45) for ACR. The area under the ROC curve was significantly higher for ACR compared with the other measures. In conclusion, measurement of the albumin:creatinine ratio in a first-morning void is the superior method to predict renal events in patients with type 2 diabetes and nephropathy.

Current issues in measurement and reporting of urinary albumin excretion

BACKGROUND

Urinary excretion of albumin indicates kidney damage and is recognized as a risk factor for progression of kidney disease and cardiovascular disease. The role of urinary albumin measurements has focused attention on the clinical need for accurate and clearly reported results. The National Kidney Disease Education Program and the IFCC convened a conference to assess the current state of preanalytical, analytical, and postanalytical issues affecting urine albumin measurements and to identify areas needing improvement.

CONTENT

The chemistry of albumin in urine is incompletely understood. Current guidelines recommend the use of the albumin/creatinine ratio (ACR) as a surrogate for the error-prone collection of timed urine samples. Although ACR results are affected by patient preparation and time of day of sample collection, neither is standardized. Considerable intermethod differences have been reported for both albumin and creatinine measurement, but trueness is unknown because there are no reference measurement procedures for albumin and no reference materials for either analyte in urine. The recommended reference intervals for the ACR do not take into account the large intergroup differences in creatinine excretion (e.g., related to differences in age, sex, and ethnicity) nor the continuous increase in risk related to albumin excretion.

DISCUSSION

Clinical needs have been identified for standardization of (a) urine collection methods, (b) urine albumin and creatinine measurements based on a complete reference system, (c) reporting of test results, and (d) reference intervals for the ACR.