Standardization external quality assurance

STANDARD REFERENCE MATERIAL CELL LINE DEVELOPMENT AND USE OF REFERENCE CELL LINES AS STANDARDS FOR EXTERNAL QUALITY ASSURANCE OF HER2 IHC AND ISH TESTING... 

Examples of quality assurance protocols that are considered standard practice in any data collection scheme include the use of both internal control samples (e.g. use of field blanks and spikes6) and external quality assurance samples (e.g. duplicate samples of known concentrations sent to different laboratories) to determine the extent of intra- and interlaboratory variation. Ensuring that the data have not been compromised or corrupted may also require setting up accessible data archives of original paper or electronic records so that the accuracy of summaries of the data published in documents and articles can be verified. 

External quality assurance (EQA) is fundamental to the standardization of clinical laboratory methods because it provides a means to compare results generated in one laboratory with those of peer laboratories subscribing to the same EQA program. EQA programs are especially beneficial since internal QA and QC procedures are limited in their ability to detect bias in analytical methods. Internal QA/QC can only detect errors that result in a deviation from the original method validation inherent errors in the method may go unnoticed. Therefore, it is helpful to compare the results produced by a new method with those from other laboratories (Burtis and Ashwood, 2001). Monitoring the performance of laboratory procedures in a consistent manner keeps the laboratory accountable, and can reveal systematic errors that would otherwise be undetected. A prominent component of EQA is proficiency testing. 

Lead in whole blood and plasma was measured by graphite furnace atomic absorption spectrophotometry (Perkin-Elmer 2380 and HGA 400) using the method of Fernandez and Hilligoss (1982). Standards and blanks were matrix-matched with test samples. Analyses on each batch of lead drinking solution were within 3% of the nominal value. Laboratory analytical quality was monitored by the UK External Quality Assurance Scheme (UKEQAS). 

Internal methods of quality assessment should always be viewed with some level of skepticism because of the potential for bias in their execution and interpretation. For this reason, external methods of quality assessment also play an important role in quality assurance programs. One external method of quality assessment is the certification of a laboratory by a sponsoring agency. Certification is based on the successful analysis of a set of proficiency standards prepared by the sponsoring agency. For example, laboratories involved in environmental analyses may be required to analyze standard samples prepared by the Environmental Protection... 

In the Intoduction to ISO 9001 it states that the quality assurance models represent three distinct forms of quality system suitable for the purpose of a supplier demonstrating its capability and for the assessment of such capability by external parties. In other words, the standard is suitable for contractual as well as for assessment purposes, but it does not actually require demonstration of capability to the assessor or purchaser unless required by the contract. 

Another external response to concerns about MCOs has been an increased interest in measuring the quality of care they deliver [35]. This interest has resulted in the development of numerous quality indicators. One example, HEDIS (Health Plan Employer Data and Information Set), is a standardized set of performance indicators used to compare health plans. Developed by the National Committee for Quality Assurance, HEDIS measures allow employers and employees to evaluate different plans. Only a small number of HEDIS indicators are related to medication use, but more drug-related indicators are likely to be added in the future. The use of quality indicators likely will increase as the measures become more refined and tested. 

There are two uses of chemical standards in chemical analysis. In the first place, they may be used to verify that an instrument works correctly on a day-to-day basis - this is sometimes called System Suitability checking. This type of test does not usually relate to specific samples and is therefore strictly quality assurance rather than quality control. Secondly, the chemical standards are used to calibrate the response of an instrument. The standard may be measured separately from the samples (external standardization) or as part of the samples (internal standardization). This was dealt with in Section 5.3.2. 

The quantification of surfactants in environmental samples needs further development, particularly in so far as quality assurance of the analysis is concerned. Since the majority of the individual isomers and oligomers involved are not yet available as standards, quantification has to be based in part on external standards of commercially available mixtures. As this holds for both LC-FL and LC-MS analyses, both suffer from this shortcoming. Yet, samples analysed with both the methods have shown good agreement of resulting data. 

In order to implement the quality policy in the daily work, quality management systems are installed, covering quality planning, quality control, quality assurance and quality improvement. To ensure that the quality assurance system is in place and effective, external standards are used, for example the DIN EN ISO 9000 ff. standard system, commonly shortened to ISO 9000 (DIN is an acronym for Deutsches InstitutfiXr Normung, meaning German Industry Standard ). 

The quality assurance sample used is an aliquot of a urine pool prepared by mixing equal proportions of 24-h samples from 20 men and women. Thus, the values obtained on GC-MS analysis should approximate true average steroid excretions. We use these values to adjust the calibration of steroids without authentic materials in the external standard. We have determined that the excretion of 18-OH-THA in the quality assurance sample should be 90 pg/24 h THAldo, 30 pg/24 h, and 18-oxo-THF, 5 pg/24 h. The amount of these steroids in clinical samples is thus calibrated against a normal excretion. 

The internal and external quality audit as per the appropriate clause in the CSA standard CAN 3-Q395 may assure that the quality standards are met in the particular situation. 

Good Manufacturing Practice (GMP) standards are a further step towards the concept of "total quality". Implementing and maintaining a GMP status requires commitment of the entire organization and constant attention by those who are in charge of quality assurance. Because of the complexity and wide scope of the subject and the amount of paperwork (some translate GMP as "Give Me Paper") extra personnel or external consultants will most likely be required. 

Quality assurance is not just a process it is a way of thinking. All staff should be well trained and motivated and be working to a common goal the production of a pharmaceutical product of a quality that is safe for the patient. The procedures should not be seen as a chore or burden to make work more difficult, but essential steps in the production of a safe, satisfactory product. Self-inspection and external audit of procedures are important processes in maintaining standards of cleanliness. Even after manufacture and distribution it is vital that the products are used properly, especially multi-use containers that are subject to potential in-use contamination. 

However, the problem of analytical transferability remains. The optimal, but usually very unrealistic, situation assumes that the analytical methods, including their calibration and quality assurance, are identical in the laboratories. A more pragmatic approach involves standardization of analytical protocols, common calibration, design of a sufficiently efficient external quality control scheme, and the use of mathematical transfer functions if the results still are not directly comparable. 

A rigid quality assurance scheme including internal and external quality control, the control of blanks and the use of control charts should be an integrated part of all PbB determinations (for details see WHO-Euro, 1981). Any change in the procedure of determination as well as the introduction of new standards or control samples should be recorded. Likewise, any changes in instrumentation or personnel should be recorded. 

This chapter deals with some methods of quality assurance, an important aspect of GLP (good laboratory practice) used to monitor drug analysis in the clinical laboratory. To ensure that the analytical results are of good quality, it is essential to find suitable methods to use for the routine procedures, and, in this connection, we discuss the use of internal and external standards and propose some methods for the documentation and verification of the analytical results, the quality of the results of GC/MS analysis being at the forefront of our discussion. 

External, i.e., outside-department, quality assurance schemes compare the accuracy of different methods and may derive targets from an all-laboratory trimmed mean (i.e., outliers discarded), on spiked values, or on a reference standard usually... 

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