Noninvasive Vascular Laboratory Quality Assurance and Accreditation

Introduction

The cost of medical care is far greater in the United States of America than in similar developed nations, while other data indicate the health outcomes in the United States lag. These observations have shifted the focus of heath policy to health outcomes or value, and have prompted an ongoing effort by funders of heathcare services to convert from volume-based payment to value-based payment. Despite the forces behind this redirection, defining meaningful value and quality in healthcare remains a challenging task. At the most basic level, Rose and Johnson have suggested that Value (V) can be thought of as a quotient of Quality (Q) and Resource utilization (R). ^, From a healthcare organization standpoint, these authors believe it is important to increase Q and reduce R as much as possible to extract the most value. This definition roughly equates outcomes with quality and thus healthcare value increases directly with improved outcomes and greater quality.

Medical errors are disturbingly common and dramatically decrease the quality of medical services. ^, Medical errors have been reported to be the third leading cause of mortality in the United States, behind heart disease and cancer. Errors in diagnosis which often involve issues with diagnostic testing are major contributors to medical error and poor patient outcomes. ^, The Institute of Medicine (IOM) has proposed six domains that contribute equally to quality care and provide a framework for the evaluation of quality in the vascular lab. These domains are safety, effectiveness, efficiency, timeliness, patient-centeredness and equitable distribution of care ( Fig. 18.1 ). As we consider quality and accreditation in noninvasive vascular laboratory, it is important to note that patient outcomes are multifactorial and that the vascular laboratory is only one factor among many contributing to quality healthcare.

In response to variations in the quality of medical care, Congress passed the Medicare Access and Chip Reauthorization Act of 2015 (MACRA), which authorized the Centers for Medicare & Medicaid Services (CMS) to develop quality and value-based reimbursement models, including the Physician Quality Reporting Program (PQRS), the Value-Based Payment Modifier (VM) and Medicare Electronic Health Records (HER) incentive programs. This act required physicians and healthcare organizations to choose between the Merit-Based Incentive Payment System (MIPS) and the Alternative Payment Model (APM). The overall objective of these programs was to incentivize healthcare systems and physicians to improve quality of care, reduce healthcare costs and advance healthcare information. These goals are directly in line with the formula mentioned above put forth by Rose and Johnson (see Ch. 200 , Alternative Payment Models in Vascular Surgery).

Herein, we describe the evolution of concepts of quality management, the application of these processes to healthcare in general, and the specific implications of these processes for the assurance of quality in the noninvasive vascular laboratory. We discuss the particular challenges of quality measurement in this setting and the adaptations and available mechanisms to institute meaningful and effective quality programs and ultimately achieve consistent quality in the noninvasive vascular laboratory (NIVL). In this regard, we review the potential role of facility accreditation by third parties as a method to manage quality performance and consider the elements of an effective quality program incorporating both internal and external components.

Development of Quality Programs in Manufacturing

Even though a systematic approach to quality improvement is a relatively recent change in healthcare, these strategies have been prevalent in manufacturing for quite some time. The Toyota Production System (TPS) is an integrated socio-technical system developed by the Toyota Motor Corporation between 1948 and 1975 to organize manufacturing and logistics in order to minimize cost and waste and deliver product to the customer in the quickest way possible. This system was based on two pillar concepts: “jidoka,” which means automation with a human touch, and “Just-in-Time” ( Fig. 18.2 ), Jidoka refers to the prevention of product defects by engaging workers in the quality process and empowering them to identify and act on potential production issues. Just-in-Time refers to the concept in which each process in the manufacturing line produces only what is necessary for the next process to continue without interruption. Just-in-Time has had pervasive impacts on industrial supply-chain management worldwide, but jidoka has greater relevance to healthcare quality. Kaizen is the Japanese business philosophy that means continuous improvement or change for the better. The widely employed Lean management model was developed based on TPS and Kaizen concepts.

Six Sigma, developed by Motorola Corporation in 1986, is another model of improving efficiency with a focus on process outputs and reduction of defects and variability. The components of Six Sigma are encapsulated by the acronym DMAIC, which refers to define, measure, analyze, improve and control. The philosophies of Lean and Six Sigma are complementary and have been combined and synergized into a more comprehensive quality model referred to as Lean Six Sigma (LSS). The LSS approach has been applied to healthcare since the mid-1990s. Healthcare systems have invested millions of dollars in this model and in similar ones to enhance efficiency, quality and outcomes. However, the positive results of these industrial quality management systems have not been clearly replicated in the medical field. In the LSS model, inefficiencies and breaks in quality are identified, passed up the chain to directors and leaders, and then changes are passed back down to middle managers for implementation. The pure TPS model rejects the top down model of quality management and attempts to create a culture of continuous improvement from the assembly line worker up to the chief executive officer. All are empowered to adapt their work in real time to improve the organization’s product and service, and thus all members of the organization are invested in its improvement.

Components of Quality Programs

Classically, quality systems are composed of two major components: quality control (QC) and quality assurance (QA). QC focuses on fulfilling specific quality requirements and grew from the need for manufacturing processes to consistently meet engineering specifications. QA is the overarching component of a quality system that encompasses QC activities and focuses on providing confidence that quality requirements are fulfilled. QA lends confidence both internally to management and externally to customers, governing agencies and certifiers. For QC to be understood in the NIVL, the vascular laboratory output (diagnostic studies) must be viewed as products that must conform to certain quality requirements or standards to meet the needs of the consumers (clinicians) and customers (patients).

Inspection and auditing are important processes in QC and QA, respectively. Inspection is the exercise of measuring, testing and comparing characteristics of a product to specific requirements, and thus the determination of conformity to a set standard. Auditing is an activity used to compare actual conditions with requirements and to report the findings to management. The distinction between these processes is important. An audit can utilize inspection techniques but should not be involved in verification that results in acceptance or rejection of a service. An audit evaluates the process and controls for production and verification. Through these processes, both QA and QC are designed to maintain standards in production and quality.

Modern quality programs in healthcare are referred to as either total quality management (TQM) or continuous quality improvement (CQI). These are structured organizational processes for involving personnel in planning and executing continuous improvements to provide quality healthcare that meets or exceeds expectations. This is very similar to the Toyota Motor Corporation culture of continuous improvement at all levels of the organization. There are several key characteristics that are common to TQM and CQI. These include: a link to key elements of the organization’s strategic plan; a quality council that includes top leadership at the institution; training programs for personnel; mechanisms for selecting improvement opportunities; formation of process improvement teams; staff support for process improvement; and personnel policies that encourage participation in process improvement at all levels. Although some of the components of a TQM/CQI program are designed more for large-scale healthcare organizations (hospital, medical system, large private practice), the principles are just as applicable to smaller in-hospital or free-standing diagnostic units. At its base, CQI recognizes that customer requirements are the key to customer quality and that customer requirements change over time. Improvements in technology, education, information management, and the economy all contribute to the need for continuous quality improvement.

An essential component of any effective TQM/CQI program is the avoidance of personal blame and a focus on managerial and professional processes needed to obtain specified outcomes. Successful continuous improvement, kaizen , relies on engagement, empowerment and commitment of personnel at all levels to quality goals. In healthcare, this philosophy has been incorporated into the concept of Just Culture and the more expansive Culture of Safety. These notions are particularly relevant in a NIVL where there is often a hierarchical structure with a medical director, laboratory supervisor, lead technician and multiple vascular technologists and the daily workflow typically separates the technical activities of sonographers and the interpretive functions of medical staff. By engaging all personnel in the NIVL as stakeholders in the quality improvement process, quality becomes more than just an abstract idea, but rather a source of pride with resultant improved performance and morale.

The application of TQM/CQI to healthcare endeavors requires adaptations to several specific conditions not found in other industries. In healthcare, the consumer (clinician), the customer (beneficiary, patient) and the payer (government/insurer) are separate with parallel but not identical goals. There is a lack of transparency regarding costs and benefits and a significant knowledge disparity among the parties. Furthermore, the uncertainties related to variability of human biology, the complex interactions of pathology and the limits of available clinical data make the identification and validation of uniform quality metrics vexing. In addition, much of the relevant data itself is subject to patient-related privacy protections (Protected Health Information [PHI] under HIPAA regulations) and peer review regulations at state and federal levels. Several compliant information gathering approaches have been developed to document current practices and identify pathways for improvement, including Quality Improvement Organizations (QIO) and Patient Safety Organizations (PSO), among others. ^, Beyond these considerations, in the assessment of overall patient outcomes and thus the quality of the healthcare system, it is difficult to determine the contribution of the diagnostic process in general and more so of the performance of a particular diagnostic facility or study.

Fundamentals of Total Quality Management

In 1931, Walter Shewhart first published on the control chart and the Plan, Do, Check, Act (PDCA) cycle, often called the Shewhart cycle. The cycle involves the following steps: (1) Plan – identify which changes are most desirable and develop a plan to reach the objective; (2) Do – search for data on hand to answer the question at hand and carry out a change or test; (3) Check – observe the effects of the change or test; and (4) Act – review the results and set a process of change into practice or modify the plan and repeat the cycle ^, ( Fig. 18.3 ).

A variant of the PDCA cycle often used in healthcare is called the FOCUS-PDCA model, and was developed by the Hospital Corporation of America (HCA). FOCUS is a lead-in to the PDCA cycle and stands for: (1) Find a process to improve; (2) Organize an improvement team; (3) Clarify understanding on the process; (4) Understand why there is process variation; and (5) Select the process improvement. The FOCUS lead-in to the PDCA cycle lays the groundwork for the Plan phase of the PDCA cycle. After completion of the cycle and once a goal has been achieved, other areas needing quality improvement can be identified and tackled.

Quantitative Imaging Biomarkers

Biomarkers are characteristics that are objectively measured and are evaluated as indicators of normal biologic function, pathologic processes or response to a therapy. Imaging technologies provide information on anatomy, physiology and function; therefore, they may be considered biomarker measurement processes. When quantifiable information is gathered from medical imaging pertaining to either normal findings or severity of disease, the procedure is considered quantitative imaging and the data generated are quantitative imaging biomarkers (QIB).

There is certain terminology important for the understanding of QIB and measurements. A Measurand is the quantity intended to be measured. A Reference value is a generally accepted value with a small amount of uncertainty used as a basis for comparison with values of quantities of the same kind. Precision is the closeness of agreement between the measurand values obtained by replication using the same or similar experimental units under specified conditions. Repeatability refers to the measurement precision with conditions that remain unchanged between replicate measurements. Reproducibility is the measurement precision with conditions that vary between replicate measurements. Bias is an estimate of the systemic measurement error. Truth or true values are the real or actual values of a quantity to be measured. ^,

In healthcare, truth and true values are often nebulous and possibly more idealistic than absolutes. All measurement has error and uncertainty, so unequivocal truth is only a theoretical construct. The term gold standard is used often in healthcare to indicate a reference standard for medical imaging. This term assumes that a measurement obtained by a specific modality, the gold standard, is the true value and has no error.

Accuracy is a term that reflects both bias and precision but there is no consensus on how to combine these two ideas. Accuracy is generally assessed by comparison to a gold standard. If accuracy is used to infer the quality of a measurement, then there should be a complete description of the uncertainty within these comparisons, including bias and precision in the gold standard itself. Accuracy assessment by comparison to a gold standard necessitates the existence of a relevant gold standard and repeated measurements of the measurand using the two modalities in question. Utilization of a gold standard comparator to assess the accuracy of vascular noninvasive tests can be difficult as some comparator modalities provide anatomic information and others physiologic information. In some cases (venous testing for deep venous thrombosis) vascular testing is itself the gold standard. If comparison to a gold standard is not possible, then blinded repeat examination by other laboratory personnel, such as alternative sonographers and interpreting physicians, could be employed. This methodology, which is in essence assessment of precision, lends itself to limitations in terms of operator and interpreter bias.

If a gold standard test exists, there are certain parameters that can be used to describe concordance between this standard and the laboratory test in question. Sensitivity is the likelihood that the NIVL test will be positive when the gold standard indicates the disease is present. Specificity is the likelihood that the NIVL test will be negative when the gold standard indicates the disease is absent. Positive predictive value (PPV) is the proportion of NIVL tests with a positive result that are correct; that is, the disease is present by the gold standard. Negative predictive value (NPV) is the proportion of NIVL tests with a negative result that is correct; that is, disease is not present by the gold standard test. These basic parameters can be calculated from the 2 × 2 binary contingency table illustrated in Figure 18.4 . The actual PPV and NPV of a test in clinical practice depends significantly on the prevalence of the condition to be tested in the population under study (pretest probability).

In this regard, it is important to not lose sight of the other domains of quality care. The effectiveness of a diagnostic study goes beyond these simple calculations and is based on the test’s utility in clinical decision-making. There is often wide variation in the use of diagnostic tests based on their perceived benefit in the evaluation of specific disease processes and on their contribution to the overall care of the patient. Scholarly societies and expert panels have developed consensus guidelines in the form of appropriate use criteria documents for various tests and disease states. However, it is difficult to determine the overall utility of a vascular laboratory study and its relationship to the ultimate clinical outcome even when evaluated under the appropriateness of use criteria. Other commonly employed measures of test or lab effectiveness include patient and provider perceptions of the test’s role in care. Surveys are often performed in NIVL to evaluate these aspects of patient-centered care. There is also an interest among patients, providers and payers to increase the overall efficiency of diagnostic tests as judged by a reduced need for either repeat testing (same modality) or supplementary or confirmatory testing with other modalities.