Proficiency Testing Program Research Articles

Use of Diagnostic Accuracy as a Metric for Evaluating Laboratory Proficiency with Microarray Assays Using Mixed-Tissue RNA Reference Samples

Effective use of microarray technology in clinical and regulatory settings is contingent on the adoption of standard methods for assessing performance. The MicroArray Quality Control project evaluated the repeatability and comparability of microarray data on the major commercial platforms and laid the groundwork for the application of microarray technology to regulatory assessments. However, methods for assessing performance that are commonly applied to diagnostic assays used in laboratory medicine remain to be developed for microarray assays. A reference system for microarray performance evaluation and process improvement was developed that includes reference samples, metrics and reference datasets. The reference material is composed of two mixes of four different rat tissue RNAs that allow defined target ratios to be assayed using a set of tissue-selective analytes that are distributed along the dynamic range of measurement. The diagnostic accuracy of detected changes in expression ratios, measured as the area under the curve from receiver operating characteristic plots, provides a single commutable value for comparing assay specificity and sensitivity. The utility of this system for assessing overall performance was evaluated for relevant applications like multi-laboratory proficiency testing programs and single-laboratory process drift monitoring. The diagnostic accuracy of detection of a 1.5-fold change in signal level was found to be a sensitive metric for comparing overall performance. This test approaches the technical limit for reliable discrimination of differences between two samples using this technology. We describe a reference system that provides a mechanism for internal and external assessment of laboratory proficiency with microarray technology and is translatable to performance assessments on other whole-genome expression arrays used for basic and clinical research.

Proficiency testing of immunohistochemical biomarker assays in breast cancer

Steroid hormone receptor expression and HER2 status have become an integral part of histopathologic characterization of breast cancer and corresponding biomarker assays have gained important prognostic and predictive impact. Because testing inaccuracy could provide a major hazard to modern breast cancer therapy, a laboratory proficiency testing program has been implemented in Germany using tissue microarrays (TMAs). In four consecutive annual trials with 142 laboratories participating on average per trial, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2) were determined immunohistochemically by participating laboratories followed by central review of all immunostains. Performance strongly depended on the ambiguity of expression of the target molecule in the test samples. In clearly positive (Allred score 7-8; Her2 3+) or negative tissue samples, the majority of participants (86%) achieved concordance rates exceeding 85%. By contrast, low expression of ER or PR (Allred score 3-4) as well as Her2 status 2+ led to considerable lower concordance rates ranging from 41% (Her2 2+) to 75% (PR). Poor reproducibility was predominantly due to inadequate laboratory performance whereas interobserver agreement (weighted kappa statistics) usually was high (>0.81). Laboratories that participated in more than one of the four subsequent trials (n = 110) showed a highly significant improvement of performance. In conclusion, a TMA-based proficiency testing of biomarkers in breast cancer has been implemented in Germany over a 5-year period and revealed reliable assessment of unambiguously positive and negative test samples. Low-expressing tumor samples with regard to steroid hormone receptor expression and Her2 status 2+ led to inaccurate evaluations by up to 59% of participants. Regularly participating laboratories showed a significant improvement of performance.

Quality control of bone marrow cytology; organization and over 7 years experience in the south‐west Netherlands

To asses the quality of bone marrow cytology of hospital laboratories in the south-west Netherlands a proficiency testing program was implemented. Two sets of bone marrow and blood smears from two patients were sent to 20 hospital laboratories using a tight time schedule biannually. Required results consisted of differential counts of 500 bone marrow cells and 100 peripheral blood cells, together with the description of morphological abnormalities and final conclusions. Twice a year the collected review data were discussed in a plenary session which was also used for continuous education. Over the past 7 years 30 bone marrow samples were evaluated. The coefficient of variations of specific cells counts was large. The amount of correct conclusions ranged from 12% to 100% (median: 61%). Participant attendance of the meetings was 90-100%. The total cost of this scheme of proficiency testing approximately amounted euro7000 per year. The presented formulae for both proficiency testing and haematopathological/cytological education is feasible and fulfilled the need of the participants.

Assessing state-of-the-quality of Jaffe creatinine assay results using proficiency testing data

Results of an interlaboratory study are reported for the determination of lead in urine. Two levels of a lyophilized material containing biologically-bound lead were prepared using pooled urine obtained from lead-poisoned children undergoing the CaNa2EDTA mobilization test. The materials were circulated to a group of reference laboratories that participate in the `New York State Proficiency Testing Program for Blood Lead'. Results of the initial round-robin gave all-method consensus target values of 145±22 μg/l (S.D.) for lot 17 and 449±43 μg/l (S.D.) for lot 20. The interlaboratory exercise was repeated some 5 years later and consensus target values were re-calculated using the grand mean (excluding outliers) of results reported by laboratories using electrothermal atomization atomic absorption spectrometry (ETAAS). The re-calculated target values were 139±10 μg/l (S.D.) and 433±12 μg/l (S.D.). The urine reference materials were also analyzed for lead by several laboratories using other instrumental techniques including isotope dilution (ID), inductively coupled plasma (ICP) mass spectrometry (MS), flame atomic absorption with extraction, ICP-atomic emission spectrometry, ID-gas chromatography MS and flow injection-hydride generation AAS, thus providing a rich source of analytical data with which to characterize them. The materials were also used in a long-term validation study of an ETAAS method developed originally for blood lead determinations that has since been used unmodified for the determination of lead in urine also. Recently, urine lead method performance has been tracked in a proficiency testing program specifically for this analysis. In addition, a number of commercial control materials have been analyzed and evaluated.

Sensitivity of sperm and embryo bioassays in the American association of bioanalysts proficiency testing program

OBJECTIVE: The human sperm survival assay (HSSA) and mouse embryo assay (MEA) are the most common quality control assays used by Assisted Reproductive Technology (ART) labs to screen consumables for toxicity. While both assays have their advantages and disadvantages, it is not clear if one assay is superior for detecting toxins. Mouse embryos provide a comparable model to human embryos but can be expensive. Sperm is readily available but there are inherent difficulties with variability between sperm samples and assay methodology and questions remain about the HSSA's sensitivity for embryo toxins.

Proficiency Testing Program for the Determination of Total Arsenic, Cadmium, and Lead in Seawater Shrimp

The proficiency testing (PT) program for 97 worldwide laboratories for determining total arsenic, cadmium, and lead in seawater shrimp under the auspices of the Asia-Pacific Laboratory Accreditation Cooperation (APLAC) is discussed. The program is one of the APLAC PT series whose primary purposes are to establish mutual agreement on the equivalence of the operation of APLAC member laboratories and to take corrective actions if testing deficiencies are identified. Pooled data for Cd and Pb were normally distributed with interlaboratory variations of 21.9 and 34.8%, respectively. The corresponding consensus mean values estimated by robust statistics were in good agreement with those obtained in the homogeneity tests. However, a bimodal distribution was observed from the determination of total As, in which 14 out of 74 participants reported much smaller values (0.482-6.4 mg/kg) as compared with the mean values of 60.9 mg/kg in the homogeneity test. The use of consensus mean is known to have significant deviation from the true value in bi- or multimodal distribution. Therefore, the mode value, a better estimate of central tendency, was chosen to assess participants' performance for total As. Estimates of the overall uncertainty from participants varied in this program, and some were recommended to acquire more comprehensive exposure toward important criteria as stipulated in ISO/IEC 17025.

The Moore–Sikora Buffer for Lime Requirement Determinations

Paranitrophenol in the Adams–Evans (AE) buffer used for determining lime requirement (LR) is considered a hazardous chemical due to its toxicity. The Moore–Sikora (MS) buffer, which mimics AE soil‐buffer pH, was developed without hazardous chemicals and is currently used for routine soil testing at Clemson University. The MS buffer was designed by considering probable chemicals with pKa values in the desired pH range, potential reaction of the components with soil, and longevity of the buffer during storage. Boric acid, 3‐(N‐morpholino)propanesulfonic acid (MOPS), and 2‐(N‐morpholino)ethanesulfonic acid hydrate (MES) were considered for the new buffer. Once chemicals were identified, a technique of finding appropriate concentrations was utilized by using an equation that could predict the acid titration of a buffer and refining pKa and concentration values until a match was found with measured pH titrations of the AE buffer. The MS buffer contains 212, 131, and 34.8 mmol L−1 of B(OH)3, MOPS, and MES, respectively. The buffer also contains 200 mmol L−1 KOH and 1 mol L−1 KCl. The MS buffer was compared with the AE buffer for determining soil‐buffer pH values on 222 South Carolina soils and 41 North American Proficiency Testing Program soils. The MS soil‐buffer pH was strongly related to AE soil‐buffer pH (r2 > 0.98). Soil‐buffer pH was slightly less with MS buffer than AE buffer, with a mean difference of 0.03 pH units. The lower soil‐buffer pH with MS buffer caused a slightly higher LR than the AE buffer, with a mean difference of 0.34 Mg ha−1 on South Carolina soils. Forty‐four percent of the samples indicating a need for lime did not have a difference in LR between the two buffers. The slightly higher LR with the MS buffer on some of the samples is not expected to raise soil pH too high above target pH values.

Proficiency testing in reticulocyte counting.

The Laboratory Proficiency Testing Program tests and evaluates proficiency of clinical laboratories in Ontario, Canada. The programme began in 1974; testing of reticulocyte counts was added in 1982. From the beginning, the goal of the programme has been to ensure that the quality of practice in Ontario laboratories facilitates good quality patient care. Testing of indirect counting methods for reticulocytes is accomplished by the distribution of stained blood films. Performance is expressed in terms of accuracy and precision. Proficiency is assessed by comparing submitted results to an all-methods' mean and result reliability by observing the coefficient of variation (CV) of the cohort. The quality of the results vary neither with the manual counting system used nor the type of laboratory. The CV commonly ranges from 25 to 30%, and this lack of accuracy appears to be inherent in the technology of manual reticulocyte counting. We conclude that manual reticulocyte counting is technologically obsolete but may be of clinical value if used in a qualitative fashion. It should probably be replaced by an automated method.

Analysis of the Analytical Performance of Laboratories Participating in Two Major U.S. Bulk Asbestos Proficiency Testing Programs

Quality assurance and proficiency testing programs have been available for 27 years for U.S. laboratories using polarized light microscopy to analyze bulk building materials for asbestos. Total enrollment in the two principal bulk asbestos proficiency testing programs conducted by RTI International peaked at nearly 900 laboratories in the mid-1990s. Enrollment has stabilized in the last 5 years at approximately 475 laboratories, and rates of return of analysis results currently exceed 95%. More than 115,000 test samples have been sent worldwide by RTI to laboratories in these two programs. A review of more than 109,000 analysis results was undertaken to determine the frequencies of various qualitative error types, the types of bulk building materials most responsible for those errors, and the accuracy of precision of semiquantitative results. This assessment revealed that a small number of bulk building materials cause the majority of difficulties in each program, although error frequencies vary between the two programs. Overall laboratory performance has improved since the programs first began in the late 1980s, with a significant decline in qualitative errors and a much less dramatic decrease in errors associated with semiquantitative estimation of the amount of asbestos present.

Summary of the 2006 College of American Pathologists Gynecologic Cytology Proficiency Testing Program

Creating a tool that assesses professional proficiency in gynecologic cytology is challenging. A valid proficiency test (PT) must reflect practice conditions, evaluate locator and interpretive skills, and discriminate between those practitioners who are competent and those who need more education. The College of American Pathologists Gynecologic Cytology Proficiency Testing Program (PAPPT) was approved to enroll participants in a nationwide PT program in 2006. Report results from the 2006 PAPPT program. Summarize PT results by pass/fail rate, participant type, and slide-set modules. Nine thousand sixty-nine participants showed initial PT failure rates of 5%, 16%, and 6% for cytotechnologists, primary screening pathologists, and secondary screening pathologist, respectively. The overall initial test failure rate was 6%. After 3 retests, 9029 (99.6%) of the participants were able to achieve compliance with the PT requirement. No participant "tested out"; however, 40 individuals "dropped out" of the testing sequence (8 cytotechnologists, 9 primary screening pathologists, 23 secondary screening pathologists). Initial failure rates by slide-set modules were 6% conventional, 6% ThinPrep, 6% SurePath, and 5% mixture of all 3 slide types. A total of 99.6% of individuals enrolled in the 2006 PAPPT program achieved satisfactory results. The data confirm that cytotechnologists have higher initial pass rates than pathologists and pathologists who are secondary screeners perform better than those who are primary screeners. There was no difference identified in overall pass rates between the slide-set modules. Further analysis of data should help define the results and ongoing challenges of providing a nationwide federally mandated proficiency testing program in gynecologic cytology.

Summary of the 2006 College of American Pathologists Gynecologic Cytology Proficiency Testing Program

Abstract Context.—Creating a tool that assesses professional proficiency in gynecologic cytology is challenging. A valid proficiency test (PT) must reflect practice conditions, evaluate locator and...

Comparison of evaluation procedures used by European external quality assessment scheme organizers for haemoglobin concentration and leukocyte concentration

This study aimed to assess currently used evaluation procedures for haemoglobin concentration and leukocyte concentration in European external quality assessment schemes (EQAS). Participating EQAS organizers were asked to complete a questionnaire gathering information on the statistical procedures used to assess the performance of participants, and to analyse an Excel file with 262 results for haemoglobin concentration and leukocyte concentration. Responses were received from the New York State Proficiency Testing programme in the US and from 11 European EQAS: Belgium, Croatia, Finland, France, Germany, Hungary, Russia, Slovenia, Spain (two organizers), and Switzerland. Five of the 11 European EQAS use fixed limits based upon experience, biological variation, state of the art, or professional consensus. The other EQAS use variable limits based upon statistical analysis of the performance attained. With the exception of the German, Hungarian, and Slovenian schemes, all European EQAS use consensus target values. The percentage of unsatisfactory results obtained by the European EQAS organizers for the given set of data varied between 0.4 and 15.6% for haemoglobin concentration and between 0 and 19.8% for leukocyte concentration.

The quality of fiber counts using improved slides with relocatable fields

A parameter based on discrepancies between reported fibers and verified fibers of relocatable slides is shown to be effective in monitoring the quality of airborne fiber counts. Analysts report only the fibers in each field examined. The verified fibers were determined by two experienced analysts, and are here considered as a "true" value. Most of the verified fibers were confirmed by the reported fibers, and the disputed fibers or fiber counting errors were all located and accounted for. In this study, reference (REF) slides were manufactured from proficiency analytical test (PAT) filter samples from the American Industrial Hygiene Association containing chrysotile or amosite. The slides were made using coverglasses bearing a grid pattern to allow accurate re-examinations. These coverglasses are an improved version of those used in previous studies. Seventy-four out of 85 amosite results and 51 out of 60 chrysotile results of REF slides were within their PAT proficiency ranges. When all reported fibers were normalized against their respective verified fibers, the average fiber count was over-estimated for amosite by 38.3% and under-estimated for chrysotile by 30.4%. The error from counting short fibers (sizing-extra) was 82.6% of the extra fibers and accounted for the 38% over-estimation of amosite fibers. For chrysotile fibers, sizing-extra errors were 74.0% of the extra fibers, but by far the larger errors were oversight-missing errors, which were 96.7% of the missing fibers and accounted for the 30% under-estimation of the chrysotile fibers. The discrepancies were found to be linearly related to counting errors as had been noted in a previous study, giving further weight to a proposed score, calculated from the discrepancy parameter (SigmaD(+) + |SigmaD(-)|)/VF(total), for evaluating the proficiencies of analysts. If a proficiency score =60 is selected, 48 out of 85 amosite results and 17 out of 60 chrysotile results satisfied this criterion in this study. The number of fiber counting errors in this study was larger than could be expected by PAT proficiency criteria. It may be useful to complement existing proficiency test programs with these REF slides. At the end of each proficiency testing round, detailed reports of discrepancies can be provided to participants so that they can improve on their skills in searching and sizing fibers and minimize their counting errors. In addition, the internal quality control program of each laboratory could include counting REF slides regularly by all analysts with control charts of (SigmaD(+)/VF(total)), (SigmaD(-)/VF(total)), (SigmaD(+) + |SigmaD(-)|)/VF(total) and RF(total)/VF(total) maintained to monitor errors, proficiencies and intercounter variations. Ten percent of relocatable slides of routine samples could also be recounted to monitor intracounter variation.

Determination of As, Cd, Pb, and Hg in urine using inductively coupled plasma mass spectrometry with the direct injection high efficiency nebulizer

The application of the large-bore direct injection high efficiency nebulizer (LB-DIHEN) for the determination of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in urine by inductively coupled plasma mass spectrometry (ICP-MS) is described. The LB-DIHEN is compared with the standard method using a concentric pneumatic nebulizer and cyclonic spray chamber. In addition to the toxicological significance of As, Cd, Pb, and Hg, these elements represent a cross-section of analytical issues including spectral interferences (e.g., 40Ar 35Cl + on 75As + and 98Mo 16O + on 114Cd +) and memory effects (Hg). In this study, the low sample consumption of the LB-DIHEN is used to reduce the volume of urine needed for analysis, and to reduce the volume of final diluted sample required for analysis. Eliminating the spray chamber and reducing the dead volume of the nebulizer reduces memory effects, especially for analytes such as Hg. The Dynamic Reaction Cell (DRC) is used in this study to attenuate the background level of ArCl + in spite of the increase in the solvent load and, in turn, the urine matrix (chloride) delivered to the plasma by the LB-DIHEN. This is the first report on coupling the LB-DIHEN to a standard autosampler for unattended sample analysis. The robustness of direct injection nebulization for routine analysis and the issues associated with automation of the sample introduction process are discussed. Although the figures of merit (sensitivity, limit of detection, and precision) determined for both nebulizers are slightly poorer for the LB-DIHEN than for the concentric pneumatic nebulizer, there is not a clinically significant difference between the results for both sample introduction systems. The accuracy of results is assessed using archived urine materials that are circulated by several different proficiency testing (PT) programs and external quality assessment schemes (EQAS). Results obtained using the LB-DIHEN were within the acceptable range established by a consensus pool generated using different methods, none of which are likely to be using direct injection nebulization. Internal quality control sample results obtained using the LB-DIHEN were compared to those obtained using the conventional nebulizer. Reported results were similar for both nebulizers. Thus, these results show that the LB-DIHEN is certainly feasible for the analysis of urine specimens.

HAIRVEQ 2006: Evolution of laboratories’ performance after different educational actions

HAIRVEQ is a proficiency testing program for hair analysis of illicit drugs organized by the Istituto Superiore di Sanità (Rome, Italy) and the Institut Municipal d’Investigació Mèdica (Barcelona, Spain). The aim of the three exercises performed in 2006 was the evaluation of 32 laboratories’ performance when analyzing the same hair sample containing opiates, cocaine and methadone, after carrying out some specific educational interventions. In the first round, the sample was sent to be analyzed following laboratory routine methodology. In the second round, standard operating procedures (SOP) for hair testing including sample preparation, method validation and qualitative and quantitative data evaluation, and an open hair sample for SOP training were also sent together with other hair samples including the one used for performance evaluation. After the second round, a workshop was held with participant laboratories to discuss methodological issues and interpretation of obtained results. An additional amount of open samples was distributed to the laboratories for implementing the SOPs. In the third round, the same unknown sample containing opiates, cocaine and methadone was resent for the final evaluation of laboratory performance. In the first round, 11 incorrect qualitative results (10 false negative and 1 false positive) were reported by seven laboratories (22%), in the second round, a reduction in the number of incorrect results was observed (4 false negatives and 1 false positive were reported by four laboratories, 13%) and in the third round, 5 false positives and 5 false negatives were reported by seven laboratories (22%). Concerning quantitative results, the scatter was similar between the three rounds and similar to the ones reported by other proficiency tests in hair analysis. More educational actions should be addressed to a group of laboratories, which did not yet show satisfying qualitative and quantitative results.

Maintenance of Certification: How Will It Affect Pathology Practice?

Maintenance of Certification: How Will It Affect Pathology Practice?

Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 μg g −1. Linear regression of whole tooth lead (μg g −1) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r 2=0.647 ( p<0.0001). Laser ablation inductively coupled plasma mass spectrometry was employed to determine lead content at micrometer scale spatial resolution in the teeth of seven goats representing the dosing range. Highly localized concentrations of lead, ranging from about 10 to 2000 μg g −1, were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg g −1) on cumulative lead dose (g) yielded a slope of 23 with r 2=0.961 ( p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats.

Implementation of a proficiency testing programme for bacterial screening in platelet preparations in Canada

Bacterial screening in apheresis platelet preparations was implemented in March of 2004 by Canadian Blood Services (CBS) using the BacT/ALERT system. The aim of this study was to develop, validate and implement an in-house proficiency testing programme to evaluate CBS performance of bacterial screening in platelet preparations. During development of the proficiency testing programme, apheresis platelet preparations were spiked with 10(1) and 10(2) colony forming units per ml of Staphylococcus epidermidis, Pseudomonas aeruginosa and Streptococcus pneumoniae. The preparations were stored at 2-8 degrees C prior to culture bottle inoculation with 4 or 6 ml on Days 7-10 (estimated time from panel preparation to testing at CBS centres). Upon implementation, a combination of four proficiency panel members, including positives and negatives, were distributed to each of the centres that participated in the programme. A survey was conducted with 43 America's Blood Centers to assess whether they screen for bacterial testing in platelet preparations and whether they have implemented a proficiency testing programme. The development of the proficiency testing programme showed that S. epidermidis and P. aeruginosa produced positive results at both concentrations and volumes on Days 7-10 poststorage. Streptococcus pneumoniae did not grow consistently and therefore was not selected for implementation of the programme. Two proficiency testing panel sets have been issued (July 2006 and February 2007) with 14 out of 15 (93%) and 14 out of 14 (100%) of the participant centres meeting the expected results for bacterial screening, respectively. The majority (72%) of the America's Blood Centers that screen for bacterial contamination have not implemented a proficiency testing programme and 94.4% of these centres are interested in developing such a programme. Canadian Blood Services has successfully implemented a proficiency testing programme for bacterial screening in platelet preparations, which will contribute to improving the safety of the platelet supply in Canada.

Diagnostic Sweat Testing: The Cystic Fibrosis Foundation Guidelines

he Cystic Fibrosis Foundation (CFF) accredits cystic fibrosis (CF) centers, located in teaching and community hospitals nationwide, which provide comprehensive diagnosis and treatment for people with CF. The CF centers are evaluated by the CFF Center Committee according to specific criteria covering the areas of clinical care, teaching, and research. here are specific requirements for sweat testing, and adherence to them is required for accreditation. In 2006, the CFF Center ommittee distributed a sweat testing guidelines memorandum to the CF center directors. Although the guidelines are based n the Clinical Laboratory Standards Institute (CLSI), formerly National Committee for Clinical Laboratory Standards, sweat esting document C34-A2 and the College of American Pathologists (CAP) Laboratory Accreditation Program Inspection hecklist items for sweat testing, they are more prescriptive for uniformity and are focused on diagnostic rather than screening weat tests. The guidelines are applicable to patients of all ages undergoing sweat chloride testing. Adherence to the guidelines is mandatory for CFF centers; however, the requirements are appropriate and adaptable for any acility performing diagnostic testing for CF. Although it may be ideal for sweat testing to be centralized at CF centers, in practice his does not occur. According to enrollment in a national proficiency testing program for sweat analysis, more than 600 laboratories erformed sweat testing in 2006. With widespread implementation of newborn screening programs for CF, the reliance on a ell-performed and well-interpreted sweat test is critical to the success of accurately diagnosing CF. Sweat chloride testing should be erformed on all infants with a positive newborn screen even in cases in which two CF-causing mutations have been identified. The following represent the 2006 CFF sweat testing guidelines, along with commentary discussing the specific guidelines.

The WADA Proficiency Testing Program as an integral part of the fight against doping in sport

This article provides a brief perspective of the World Anti-Doping Agency (WADA) in the context of the fight against doping in sport and of the WADA Proficiency Testing Program as an essential element of the World Anti-Doping Program. The WADA Proficiency Testing Program exists within the framework of the WADA-accredited laboratories and is aimed at improving the effectiveness of the fight against doping by testing the ability of the laboratories to reliably identify and measure the substances and methods defined in the WADA Prohibited List. The paper provides an overview of the WADA Proficiency Testing scheme with respect to organization, test composition and evaluation of anti-doping methods and techniques. Scientific research is mentioned in the context of WADA’s involvement in generating reference materials for improvement of analytical activities of the WADA-accredited laboratories. WADA’s funding of a reference material for 19-norandrosterone in human urine is illustrated as an example.