Two distinct categories of evidence contribute to diagnostic reasoning that may impact the ability to assess parameters of diagnostic correctness or adequacy. One involves the creation and use of durable artifacts, things that persist and can be independently reviewed after the point of care. Healthcare delivery creates a vast range of such artifacts, such as radiology images, pathology specimens, recordings of physiological parameters, progress notes, and time-stamped data entries. Durable artifacts can be reviewed both asynchronously and by multiple reviewers to achieve a diagnostic consensus of adequacy or correctness or to assess quality.
The other category of evidence includes physical findings that may not generate durable artifacts and may evolve over time. Examples of this type of evidence include rashes, visual estimations of blood loss, and manifestations of cognitive, sensory, or motor deficits. Even patient odors may provide diagnostic evidence. As some of these findings may evolve, it can be difficult to seek secondary verification or consensus. It can also be difficult, or at least cumbersome, to capture this evidence directly, and often descriptions must suffice.
In addition, intangible factors may impact the diagnostic process, such as the:
- Quality, accuracy, and thoroughness of the history obtained from the patient or the patient’s representatives.
- Ease of access to laboratory, imaging, consultant, and other results.
- Thoughts and conversations as well as actions and circumstances (e.g., resource limitations, interruptions) that are not recorded in formal documents or retrievable for later objective review. These are often captured only in the form of recall or sometimes not at all.
An important characteristic of diagnostic evidence is that it requires interpretation and synthesis that can change based on incoming, new, and sometimes conflicting information. What is thought to be a conclusion based on fact at one moment can be discarded later when additional details become available. Thus, evidence and interpretation of adequacy are only as good as their fit with the context and clinical questions they are designed to address.
Conclusions about diagnostic adequacy, correctness, accuracy, quality, and ultimately excellence are complex and need to be grounded in what is known, knowable, and sometimes yet to be discovered. Judgments about adequacy of diagnosis are only further complicated by the inherent variability in disease expression in biological systems, dynamic nature of evolving disease processes, and uncertainty that inevitably accompanies diagnostic reasoning.
