Overview - quality managementA question often asked by management or a regulatory authority relates to the cost of implementing a quality system. The real question to be asked however, is how much is poor quality going to cost (or how much is poor quality costing now)? The principal issue here, particularly when discussing health economics, is the influence of “cost shifting”. In the current context of laboratory or POC testing, poor quality in one sector of the health system adds costs to another sector as increased resource requirements. Poor quality in laboratory testing often results in increased doctor visits, additional unnecessary test procedures, inappropriately changed medication or additional unnecessary medication, and / or hospitalisation. The real cost of not identifying testing problems, of unnecessary repeat testing and poor patient outcomes, is often hidden until a quality system has been implemented. In quality management texts this is usually described as the 1-10-100 rule: that is, $1 of prevention is better than $10 of corrective action (or of appraisal costs or retesting costs), which is better than the $100 required to recover from a failure.
The NACB Laboratory Medicine Practice Guidelines - Evidence-based practice for point- of-care testing referred to previously, briefly describe the role of quality management and the requirement for QC and QA.61 They acknowledge the difficulty of providing evidence- based data with the statement “The literature about quality assurance (QA) and quality management (QM) of POCT is by and large not evidence based, … due in large part, to the difficulty of assessing the causal impact of POCT on medical errors.” However, the NACB do explicitly state “QC and QA are integral components forming the basis of the QM hierarchy of the clinical laboratory.” … “The performance goals of POCT are no different from those of the traditional laboratory …”.
The Australian government point-of-care testing in general practice trial has also provided confirmation that quality management practices are required for POCT. As indicated previously (item 5.1 above), Chapter 14 of the report discusses the issues of regulation and quality management for POCT.14 The particular quality management procedures used in the trial were those described in Interim standards for point-of-care testing in general practice.13 The quality management system used in the trial included:
- device operator training and certification
- IQC (internal quality control) and EQA (external quality assessment)
- an accreditation program based on the (interim) standards for POCT in general practice.
Quality assurance, quality control and external quality assessmentQuality assurance (QA) is that aspect of quality management focused on providing confidence that quality requirements (quality goals, fitness for purpose) are being fulfilled. The NACB Laboratory Medicine Practice Guidelines - Evidence-based practice for point- of-care testing describe POCT QA as “ … all the measures taken to ensure that investigations are reliable” … and include:61
- correct identification of the patient
- appropriate test selection
- obtaining a satisfactory specimen
- analyzing it and recording the results promptly and correctly
- interpreting the result accurately
- taking appropriate action
- documenting all procedures for reference
- internal QC requirements
- correction of nonconformities
- participate in an EQA scheme (and perform adequately as part of clinical governance).
The terminology with regard to quality assurance may at times seem inconsistent. Depending on the context or particular publication, quality assurance may also be synonymous with proficiency testing, external quality assurance (EQA) or external quality assessment (also designated as EQA). NPAAC, in their Requirements for participation in external quality assessment, 2009, define external quality assessment (EQA) as “A program in which multiple samples are periodically sent to members of a group of laboratories for analysis and / or identification, in which each laboratory’s results are compared with those of other laboratories in the group and / or with an assigned value, and reported to the participating laboratory and others. Such a program may also compare an individual’s results with their peer group.”153 This procedure allows testing sites to check the validity of their own results by comparison to other sites, through a process of testing identical samples with unknown values.
Participation in EQA provides an assessment of accuracy by way of a performance comparison with all instruments and with other users of the same instrument.95,154 Issues with regard to commutability are probably even more contentious for POCT than for central laboratory procedures and this will certainly limit traceability to a primary standard. However, participation in EQA will still provide a comparative peer assessment which is a crucial element in the quality assurance process. Issues with regard to the current challenges and future directions of proficiency testing have been recently reviewed.155
In its simplest form, quality control (QC; often referred to as internal QC or IQC) assesses the performance of a testing system in real time and compares it to previously accepted performance criteria.154 This concept was first applied to quantitative laboratory testing with the use of standardized control charts, by Levey and Jennings in 1950.156
In addition to the many pre-analytical factors which require documentation and “control”, analytical QC as described by Gill and Shephard95 and Gill and Watkinson154, generally require the analysis of a defined QC material to confirm that results are consistent with previously defined limits. Device manufacturer’s procedure manuals usually outline suggested QC procedures, and a plethora of publications provide both general and specific advice.61,94,95,132,154
The requirements for quality control and quality assuranceAs stated above, quality assurance (QA) and quality control (QC) are integral components of the quality management process. In addition, existing regulatory requirements from all jurisdictions and evidence-based practice guidelines are fully supportive of this quality management approach. Failure to ensure that testing processes are performing to specification contributes to inaccurate results and incorrect patient management, inappropriate or unnecessary medical treatment and poor patient outcome(s). Scientific and laboratory testing devices do not come with a lifetime performance guarantee. Continuous assessment is required to ensure on-going performance is maintained within manufacturer’s specification.
Standard 8 of NPAAC document Requirements for pathology laboratories, 2007, states:
- S8.1 “A pathology service must audit its operations as part of the quality system in order to determine compliance of the service with current regulatory and accreditation requirements”
- S8.2 “Laboratories must be continuously enrolled, participate and perform to an acceptable standard in external proficiency testing programs that cover all test methods performed in the laboratory where such programs are available”.157
- performance expectations that cover pre-analytical, analytical and post-analytical components of the service
- performance expectations after consultation with user physicians and other healthcare workers
- periodic audit to determine that the service is meeting its established performance expectations
- a program of performance comparisons to that of the central or core laboratory
- periodic review of the service patterns of practice against established, validated, external benchmarks
- review of the QA program findings by a management team.”61
As suggested previously, the required analytical performance of a test (fitness for purpose) is determined by its intended clinical use and not by the location where the testing occurs. This is also implicit in the CLIA regulations, which impose site-neutral standards for laboratory practice. Professional commentators on quality issues in POCT all appear to agree that accuracy and reliability of laboratory testing (which includes POCT), should be equivalent irrespective of the testing site in order that equivalent clinical decisions can be made.
The requirement for QA and QC in POCT is actually enhanced by the apparent simplicity of the technology. Persons without laboratory training frequently perform POC procedures in a clinical setting, where results are available for the immediate influence on patient treatment. As stated in Chapter 1 of the NABC guidelines, “Because POCT results are treated comparably to those generated by the central laboratory for patient care, it follows that the quality requirements are the same regardless of the testing site, process, or procedure. At the same time, the unique characteristics (of POCT) … add special requirements to QA/QC.”61
The medical literature contains many articles which outline the importance of QA and QC for POCT. There are even more articles which describe the inaccurate performance claims of some device manufacturers (caveat emptor). Regulatory measures for laboratory testing or POCT are designed to guarantee that patients receive appropriate and cost effective results, and testing devices and procedures comply with the relevant technical standards. As discussed by Sautter and Lipford, “Inherent with POCT growth come challenges in performing high quality accurate testing. Decreasing laboratory errors and improving patient safety must also be considered …”.127
The importance and detailed application of QA and QC in POCT is well described in any number of peer reviewed articles.92,93,94,95,96,154,158 In a similar manner, the application of ISO 22870 to POCT in the UK has been provided by Thomas.120