|
|
||||||||
General Clinical Chemistry |
1 Washington University School of Medicine, St. Louis, MO.
2 National Health Laboratory, Asmara, Eritrea.
3 Pathologists Overseas Inc., Del Mar, CA.
aAddress correspondence to this author at: Washington University School of Medicine, Department of Pathology and Immunology, Box 8118, 660 S. Euclid Ave., St. Louis, MO 63110. Fax 314-362-1461; e-mail mscott{at}labmed.wustl.edu.
| Abstract |
|---|
|
|
|---|
Methods: A system emphasizing simplified instrumentation, single source reagents, technical education and support, and simple QC algorithms was established in the small African nation of Eritrea. The same reagents were used on different analyzers, as well as the same lot numbers of QC material. To allow traceability of Eritrea results to an accredited US laboratory, the reagents and QC materials were identical to those used in a large university hospital in the US, and patient samples were frequently exchanged between locations.
Results: QC values for 23 clinical chemistry tests in the Eritrean National Health Laboratory compared well to values obtained in the US, showing some statistically different values but no clinically significant differences. QC values were also stable over time in Eritrea. Patient sample values from Eritrea correlated well to values from the US, with r values ranging from 0.71 to 0.99. For 9 chemistry tests, small regional laboratories in Eritrea produced QC and patient values that usually compared well to those from the Eritrea National Health Laboratory, but markedly discrepant values were occasionally observed that prompted investigation.
Conclusion: A simple but sustainable national laboratory system has been established in the developing nation of Eritrea.
| Introduction |
|---|
|
|
|---|
Pathologists Overseas and Barnes-Jewish Hospital at Washington University Medical Center have been providing reference laboratory services to the nation of Eritrea since 1998 (8). Most specimen referrals from Eritrea have been for endocrinology, therapeutic drug monitoring, immunology, and lipid testing. In addition to providing previously unavailable tests, this effort helped determine priorities regarding which tests to implement in laboratories in Eritrea (8).
In 1998 the only chemistry tests available in Eritrea, a nation with a population of approximately 3 million, were Na, K, Cl, total CO2, calcium, creatinine, urea nitrogen, and glucose (GLU)1 performed on a Beckman-Coulter CX3 analyzer located at the Central Health Laboratory [renamed the National Health Laboratory (NHL)] in the capital city of Asmara. At that time this project began with several broad goals: (a) expand clinical chemistry testing at the NHL, (b) implement limited chemistry at regional hospitals, (c) provide training in quality assurance, and (d) establish simple, sustainable laboratory policies and procedures. To increase the chance of long-term success we limited the sources of reagents, used simple instrumentation in the regional hospitals that was calibrated to agree with the NHL results, trained local technologists to maintain and repair the analyzers, and maintained traceability of results at NHL (and therefore the entire country) to the laboratory at Barnes-Jewish Hospital. This process was aided by the use of the same QC material and reagents at all Eritrea locations and at the clinical chemistry laboratory at Barnes-Jewish Hospital.
| Materials and Methods |
|---|
|
|
|---|
We expanded clinical chemistry testing to the regional hospitals by use of small manual or semiautomated instruments with open reagent systems. The instruments had to be capable of using the same Roche reagents used at the NHL. We met with vendors at national and international clinical chemistry meetings, and after trying instruments from several manufacturers we obtained an ERBA SmartLab and Chem-Pro analyzers from Transasia Biomedical in December 2001. These instruments were kept at the NHL for training purposes and others were placed in the regional hospitals. We introduced SmartLab analyzers in Keren and Mendefera in 2003 and at the Orotta Hospital in Asmara in 2004.
The SmartLab analyzer is a simple, bench-top, random-access, 8-wavelength spectrophotometric analyzer that can operate in end-point, kinetic, and 6-point calibration curve modes of analysis. This analyzer has a single sample/reagent probe, 45 sample cups, and 16 reagent boats and can perform 120 tests per hour. Fluidics are controlled by a single peristaltic pump, and all user interface is via a front panel touch-pad and 7-inch cathode ray tube. Tests performed on the SmartLab were ALT, ALB, ALP, AST, BUN, GLU, serum creatinine, TBIL, and TP.
On the basis of the countrys ordering patterns from Barnes-Jewish Hospital, a Roche Elecsys 1010 analyzer was purchased in 2002 and installed at the NHL to perform tests for follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), estradiol, progesterone, prolactin, and testosterone (8). Multiple hematology analyzers (Beckman- Coulter ACT-10 and ACT-Diff) were donated by Beckman-Coulter to use in the regional hospitals, but a report of their performance has not been included in this study.
Barnes-Jewish Hospital.
Routine chemistry testing was performed on Roche Hitachi 747 analyzers from 1998 until June 2004, when the analyzers were replaced by Roche Hitachi Modular P systems. Immunoassays were performed on the Bayer Centaur. HbA1c testing was performed on the Dade Behring Dimension RxL.
instrument maintenance
In 2000 a medical technologist volunteer in Eritrea (SM) attended Roche USA training courses on Hitachi 704/717 maintenance and Elecys 1010 operation. A Roche biomedical engineer spent 2 weeks in Asmara in December 2002 training local engineers and technologists on Hitachi 704/717 maintenance. This individual also installed and provided training for use of the Elecsys 1010 analyzers. Since that time all maintenance and repairs have been carried out by local technologists/engineers with e-mail and phone support from Roche USA and Roche Germany. This support has continued even after Roche ended commercial support of the Hitachi 704/717 analyzers in August 2005.
reagents
All reagents, with the exception of tests performed on the Beckman CX3 analyzer in Asmara, were obtained from Roche Diagnostics (Indianapolis, IN, and Mannheim, Germany). At Barnes-Jewish Hospital Roche reagents were used on the Hitachi 747 and Modular analyzers. When the package insert of the reagent also provided parameters for the Hitachi 717, the same catalog number of reagent was used in Asmara, with the manufacturers suggested parameters applied for the 717 or 704. The Roche reagents used on the 704/717 were also adapted for use on the ERBA analyzers. The parameters provided for the 704/717 (e.g., ratios of sample to reagent volumes, incubation time, kinetic time, temperature, and wavelength) were used as a starting point to develop parameters at Barnes-Jewish Hospital for the 8 chemistry tests listed above.
The initial ERBA analyzer we evaluated (Chem-Pro) is designed to use a single-reagent system, because it can mix and incubate only the sample plus 1 reagent. Most of the Roche reagents are 2-part reagent sets, however, and for the Chem-Pro and the ERBA SmartLab analyzers, the Eritrean laboratories mix reagent 1 (R1) and reagent 2 (R2) in the same ratio as the Hitachi parameters just before adding the mixture to the reagent vessel. Methods were calibrated with the CFASTM (calibrator for analytical systems) from Roche Diagnostics. Absorbance factors on the ERBA were adjusted when necessary so that patient samples yielded results equivalent to those obtained at Barnes-Jewish Hospital. Roche provided special pricing for all reagents for this project.
In December 2002 the Eritrean Ministry of Health began purchasing Roche reagents from Roche Diagnostics Germany. The chemistries for 3 of the tests, ALT, ALP, and AST, differed between the US and European reagents, and new procedures had to be developed for the ERBA analyzers. For instance, the concentration of the R1 AST reagent from Europe is 4 times that of the R1 AST reagent in the US, whereas both versions have the same R2 reagent concentrations. To mimic parameters used at Barnes-Jewish Hospital, the European R1 reagent was diluted 1:4 before mixing with R2 in a 5:1 ratio to be placed in the SmartLab reagent tray vessel.
QC material for routine chemistry testing on the 704/717 and the ERBA analyzers was the same material and lot number used at Barnes-Jewish Hospital. From 1998–2000 it was Dade Monitrol, from 2000–2003 it was MAS material, and since 2003 it has been Bio-Rad Liquid QC. QC material for HbA1c and the Elecsys immunoassays was Roche Precitrol.
laboratory information system
In 2000, the Comp ProMed Corporation (Santa Rosa, CA) donated Polytech software, which runs on free-standing personal computers without the need for a server. From a single screen this software allows patient data entry, test orders, accession number generation, and result review. A particular advantage of this system is that the entire database is constantly being updated on the multiple personal computers linked as a network in Asmara. QC functions of this software include QC analysis and flagging, user-definable Westgard shift analysis, QC summary reports, and Levy-Jennings graphs. Patient and QC results are entered manually. Mallinckrodt (St. Louis, MO) and Washington University donated personal computers and other hardware.
quality assurance
Volunteers for Pathologists Overseas provided training sessions in Eritrea on laboratory QC and quality assurance procedures. QC material was assayed a minimum of 20 times over at least 5 days to establish initial mean and SD for tests performed on the Beckman and Roche analyzers. Large deviations from the Barnes-Jewish Hospital values for this material were investigated and recalibrated. If differences were still observed, adjustment of k factors (reciprocal of calibration slope) were made. A simple 2–2SD Westgard rule was used for result acceptance (9). Results were reported if both the high and low QC samples gave values within an interval determined by Barnes-Jewish Hospital to approximate 2 SD of the expected mean in Eritrea. If both QC samples were outside this range, patient results were not reported. When only 1 QC sample gave a value outside of the range, the same QC sample was analyzed again, and if the repeat value was within the acceptable interval patient results were reported.
Patient samples and human serum pools were periodically (initially every 2 weeks and subsequently once a month) exchanged between Barnes-Jewish Hospital, the NHL, and the regional health laboratories to continually assure that results obtained were equivalent. Five to 10 samples were shipped to Barnes-Jewish Hospital via express air on cold packs. Samples would generally arrive in St. Louis within 48 h of leaving the NHL in Asmara and were usually still cool but not 4 °C. Stability of the analytes under these shipping conditions was determined by analyzing samples in the US and then shipping them to Asmara and back for reanalysis (8). Analytes were determined to be stable if the repeat results were within Clinical Laboratory Improvement Amendments (CLIA) 1988 criteria for acceptable error (10). Comparison of results was assessed to determine whether maintenance, recalibration, adjustment of calibrator values, or parameters was needed to align results between locations.
| Results |
|---|
|
|
|---|
Limited menu testing using Roche reagents on the SmartLab analyzers began in the regional centers at Mendefera and Keren in 2004. Test volume in these centers was 3778 in 2004 and 2235 in 2005. Volume decreased in 2005 because 1 center experienced repeated QC failures that prevented many results from being reported.
quality assurance
Shortly after the project began in 1998 good agreement was obtained for QC results from tests performed on the Beckman CX3 in Asmara compared with the Hitachi 747 analyzers in the Barnes-Jewish laboratory (see Supplemental Data Table 1 that accompanies the online version of this article at http://www.clinchem.org/content/vol53/issue11). Values from the most recent QC material in the US and the Eritrea laboratories for March 2005 are shown in Table 1
. Good agreement was observed for almost all tests with the exception of some enzymes. Imprecision of most tests in Asmara was slightly greater than that observed in the US, but regional laboratory values were less precise. In many cases statistically different means for QC values were observed, but the differences were not deemed to be clinically relevant. Examination of QC means 1 year apart showed consistency for the Eritrea laboratories (Table 2
).
|
|
patient comparisons
Patient specimens were frequently exchanged between laboratories to ensure the reporting of similar values in all locations and the appropriateness of the US-based reference intervals used in Eritrea. The relationship between values obtained from patient samples in the US and Asmara over a 4-year period for all 23 chemistry tests is shown in Supplemental Data Table 2, and relationships for values obtained over a 2-year period for 8 chemistry tests at the regional laboratories and Barnes-Jewish Hospital and the regional laboratories and Asmara, respectively, are shown in Supplemental Data Tables 3 and 4. Although regression studies suggest reasonably good agreement, difference plots of individual patient sample comparison values from the NHL in Asmara (Fig. 1
) and from the regional laboratories (Fig. 2
) reveal periodic discrepant results, particularly from the regional laboratories. Reporting of patient results was suspended when these differences were observed. For instance, in May 2004 reporting of ALP was suspended in Keren and Mendefera when the patient comparison values showed marked differences, with the regional laboratory values averaging 51 U/L lower than Barnes-Jewish or Asmara values. Similarly, reporting of ALT was suspended several times in late 2004 and the 1st half of 2005 when markedly discrepant patient comparison results were observed (Fig. 2
). Fig. 3
shows results of immunoassay patient comparisons. Such comparisons helped identify the misassignment of a calibrator value for HbA1c that led to reporting markedly increased values for several weeks when HbA1c values were >10% (Fig. 3
). This discrepancy was not apparent from QC values, for which mean HbA1c values were <10%.
|
|
|
| Discussion |
|---|
|
|
|---|
Another advantage to this approach was that the regional laboratories, where storage and environmental conditions are not optimal, did not need to keep separate inventories of reagents or QC materials but could simply request reagents from the NHL when needed or when QC values suggested deterioration of the reagent on hand.
With the ability of the regional laboratories to compare patient sample results to those obtained in Asmara, and also Asmara to Barnes-Jewish, which is CAP certified, the foundation was laid for a self-sustainable and simple but high-quality laboratory system in Eritrea, traceable to a large extramural QC program.
Although this approach may appear straightforward, there were numerous hurdles to cross. For instance, the ERBA analyzers were not the 1st simple bench top analyzers to be implemented, nor were Roche reagents the 1st reagents we tried to implement on the Hitachi analyzers in Eritrea. In 1999, we had purchased several small table-top analyzers as well as a floor-model, random-access analyzer similar to the Hitachi 717. For these instruments we used reagents from a US manufacturer of generic clinical chemistry reagents. This plan failed because of the lack of technical and spare parts support from the manufacturer of the instruments and because the reagent manufacturer closed its clinical chemistry reagent business. We had developed parameters for the table-top test instruments and begun implementation when repairs, spare parts, and finally reagents became too difficult to obtain, thus undermining the sustainability of the laboratories Thus, in late 2001, we visited with several vendors at national and international laboratory medicine meetings and made the decision to change to Roche reagents and the ERBA Transasia instruments for the regional laboratories.
Support from Transasia and Roche manufacturers has been exceptional, with "champions" in each company. The initial decision to use the manual, single-test ERBA Chem-Pro device in some regional hospitals was because of the low test volume and an inexpensive labor force. However, we found QC precision to be unacceptable in the field, and trained labor became a limiting factor. For these reasons the higher throughput, semiautomated ERBA SmartLab analyzers were put to use in all regional laboratories. As the Ministry of Health developed resources to obtain Roche reagents, these were supplied from Europe, a change that necessitated adjusting parameters for those tests whose formulations differed between Europe and the US.
Enzyme measurement in the regional laboratories has presented the greatest challenge, with multiple QC failures and frequent poor agreement of patient values to those in the US and Eritrea. For instance, between December 2004 and June 2005 repeated QC failures in Keren for some enzymes resulted in test values not being reported at this location (Fig. 2
). We investigated reagent temperature and storage conditions but ultimately identified use of poor-quality water for cleaning glassware and reuse of disposable cuvettes and reagent boats on the SmartLab as causes of QC failure and/or assay bias. High blank signals also would occasionally result in large constant biases for some tests. Obvious problems were usually easy to identify when an NHL technologist or Pathologists Overseas volunteer visited the regional laboratory. However, troubleshooting shifts in QC or patient values compared to the Barnes-Jewish values, which are reviewed monthly, often required subtle changes of the factors or calibrator values. This process necessitated rapid facsimile and e-mail exchange of data between Asmara and the US. Unfortunately the regional laboratories do not have access to either of these technologies, and adjustments and corrections at these locations could often take several weeks. Patient results were not reported once unacceptable QC values were observed, but then solving these problems may require weeks. A new challenge is the anticipated decline in support and availability of parts for the Hitachi 717. In 2007, the NHL will transition to the Hitachi 902 as its main chemistry analyzer.
Despite such hurdles this project has increased the availability of laboratory services to the population of Eritrea. The approach we have taken centers on maintaining the quality of test results as well as a consistent inventory of reagents and parts. Instituting a culture of quality by having medical technologist volunteers in Eritrea for 6 years, by training local technicians, and by having a simple laboratory information system in place were all important contributors to this project. Also essential is the availability of local people with the skill and drive to implement rigid QC procedures, and a political environment that supports these individuals to further the goals of this project. In May 2007, implementation of the SmartLab chemistry analyzers was begun in 5 more regional hospitals, and initial patient comparison data have shown good correlation with the Barnes-Jewish Hospital values for most tests.
At least one impact of these services on the health of the Eritrean population can be found in the population of individuals with diabetes. In conjunction with providing HbA1c testing for Eritrea, Pathologists Overseas also provided visits by diabetes educators and endocrinologists. These visits together with GLU meter availability at numerous clinics resulted in median HbA1c values decreasing over a 2-year period (11). Chronic disease is now prevalent in the developing world (12)(13)(14), and, as therapy for HIV becomes more common, we believe that routine clinical chemistry and hematology laboratory services will become as essential as testing for infectious disease. It is our hope that the work of Pathologists Overseas in Eritrea can help provide a starting model for developing sustainable laboratory services in developing countries.
| Acknowledgments |
|---|
Financial disclosures: None declared.
Acknowledgments: We thank the many volunteers of Pathologists Overseas who have aided this project. Particular thanks go to Jack Wareham (Beckman-Coulter) and Jeff Fisher (Comp ProMed), who facilitated the donation of instruments and software and the time of their support staffs; Suresh Vazirani (Transasia) who always resolved issues and problems rapidly; Lori Gabrek who was a champion of this project at Roche Diagnostics; Terry Salley (technical service department of Roche Indianapolis) who resolved so many service issues via e-mail with great patience; Saleh Meky (Minister of Health of Eritrea) who was always supportive; and Dr. Curtis Parvin for performing t-test analysis.
| Footnotes |
|---|
| References |
|---|
|
|
|---|
The following articles in journals at HighWire Press have cited this article:
![]() |
D. W. Windus, J. H. Ladenson, C. K. Merrins, M. Seyoum, D. Windus, S. Morin, B. Tewelde, C. A. Parvin, M. G. Scott, and J. Goldfeder Impact of a Multidisciplinary Intervention for Diabetes in Eritrea Clin. Chem., November 1, 2007; 53(11): 1954 - 1959. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |