Diagnosis and the Value of Pathology

Laboratory testing – overseen by pathologists – provides critical information that determines accurate diagnoses, guides treatment decisions, and permits early disease detection. Additionally, pathologists help monitor chronic diseases, assess treatment efficacy, and screen for genetic abnormalities through their laboratory expertise. However, measuring the value of pathology’s contributions can be challenging. Traditional measures, such as cost and test volume, do not capture the impact of the practice of pathology on critical factors, such as time to diagnosis – which directly impacts patient outcome and quality of life (1, 2).

The turnaround time (TAT) of a laboratory test is often measured from the time the sample is collected to the time the result is reported. It includes the time it takes to transport the sample to the laboratory, to perform the test, and to report the results. The longer it takes to get results, the longer the patient may go without appropriate treatment or care. Yet, those results must be interpreted in context to arrive at a diagnosis. A fast TAT on an incomplete or inappropriate panel of laboratory tests won’t assist in an accurate diagnosis or lead to appropriate treatment.

In contrast, diagnostic turnaround time (DTAT) is a concept that captures the time to diagnosis. DTAT begins when a patient presents an initial complaint and includes the time it takes to order the correct laboratory tests, perform the tests, review the result, integrate them with other clinical data, and arrive at an accurate diagnosis. This new concept of DTAT highlights the crucial role of the laboratory and pathology in diagnosis, as the laboratory provides the critical information necessary to determine diagnosis and treatment. Pathologists themselves are uniquely suited to provide expert interpretation of laboratory results in clinical context. Indeed, pathology is increasingly being recognized as a diagnostic medical specialty. Specialists in both anatomical pathology and clinical pathology disciplines are trained to critically evaluate laboratory results, synthesize them with the radiographic and clinical data, and decipher the diagnosis. Conceptualizing pathologists as diagnosticians emphasizes their critical role in modern medicine and places them at the forefront of the diagnostic process, moving pathologists out of the lab and into the spotlight. We propose a paradigm shift in which pathologists become stewards of the diagnosis, rather than stewards of the laboratory. Therefore, measuring DTAT becomes essential to understanding the quality and efficiency of pathology services, and the value of pathology in the healthcare system. 

In this new paradigm, optimizing DTAT becomes of critical importance. Hypothetically, a diagnosis might require both test A and test B, both of which have a TAT of six hours. The TAT of test A could be shortened to one hour, producing an average TAT of 3.5 hours. However, because both test A and test B are needed to produce a diagnosis, the DTAT remains at six hours. Focusing on the DTAT requires a new mode of thinking about laboratory workflow – one that moves away from siloing the volume, cost, and TAT of individual tests and instead uses a global integration that places diagnosis at the forefront of laboratory production. Diagnosis becomes the primary output of the laboratory and of pathology as a specialty, and DTAT becomes the primary quality measure. 

In reconceptualizing pathology as a diagnostic specialty, greater emphasis is placed on synthesis of information. Arriving at the right diagnosis for the right patient requires the integration of laboratory, histopathological, radiographic, and clinical data. We envision artificial intelligence (AI) as a tool that will assist pathologists in this integration. Pathologists have always been at the forefront of adapting new technology to the rigors of clinical diagnostics. We foresee pathologists will be the first to use AI, and that it will become a powerful catalyst in pursuit of diagnosis, especially as the volume of available data on any given patient continues to rapidly expand.

One way that pathologists are currently contributing to reducing the DTAT is through diagnostic management teams (DMTs). DMTs are multidisciplinary teams that work together to diagnose complex cases and are typically led by pathologists. Originally conceptualized in the 1980s, DMTs allow pathologist experts to interpret laboratory tests, provide diagnoses, and guide treatment in conjunction with their colleagues (3). DMTs can reduce healthcare costs by reducing unnecessary testing and reducing diagnostic errors (4,5). Moreover, DMTs can be used to improve DTAT by streamlining the diagnostic process and improving diagnostic accuracy. The value of rapid DTAT has direct benefit to the healthcare system by reducing costs, but it also has direct benefit to patients. A prompt and accurate diagnosis can substantially improve patient outcomes and quality of life. Thus, pathologists –  in their role as diagnostic experts – contribute more to patient care than simply supervising a laboratory. They are key contributors to diagnosis, reducing DTAT, and providing the best quality of care our modern healthcare system can provide.