In the previous chapter, the case was made for why physical therapists need to know about diagnosis. The idea emphasized in that chapter was that physical therapists have the ethical obligation to engage in a systematic process of diagnosing a disorder by differentiating between the many diseases that may cause the symptom. Diagnostic reasoning is one component of clinical reasoning by expert physical therapists. According to Edwards and colleagues, diagnostic reasoning includes the "… formation of a diagnosis related to physical disability and impairment with consideration of associated pain mechanisms, tissue pathology… ."1 (p322) Indeed, determining the cause of a patient's symptoms is the initial stage of deciding how to treat a patient. As previous chapters have pointed out, the term diagnosis has dual meanings. It refers to the clinical reasoning process of determining the sources of a patient's symptoms. This term is also used to describe the outcome of the clinical reasoning process, which is a label that serves as shorthand communication among different health care providers. When the diagnostic label is coded, it can then be used to inform the processes of disease tracking and insurance reimbursement. The purpose of this chapter is to discuss a clinical reasoning process aimed at determining the pathology responsible for a patient's symptom(s), using the presenting symptom as the starting point.
Both Diagnosis and Medical Screening Have Roles in Physical Therapy
Systems-based processes for medical screening have been proposed for use by physical therapists in order to move from diagnostic uncertainty to a sufficient level of certainty to determine if the patient/client requires referral to another health care provider. However, medical screening is different than diagnosis. As part of any effective assessment by a physical therapist, the patient is asked a series of questions, commonly called the review of systems. The goal of the medical screening portion of the subjective examination is not to determine the pathology or pathophysiology underlying a patient/client's clinical presentation, but to ensure that nothing that may impact the patient's well-being has been overlooked. The organization of the review of systems is based on anatomical structures or physiological systems.2 Typically, these questions are integrated into a thorough questionnaire format that is designed to cover all areas and systems.
The clinical data acquired from the review of systems or medical screening is then typically examined by the physical therapist for the presence of Red Flags. In 1994, the U.S. Agency for Health Care Policy and Research3 released a brochure describing symptoms and signs that may indicate the presence of serious pathology in patients with low back pain, which have become known as Red Flags. Red Flags are commonly interpreted to signal an automatic need for patient/client referral to another health care provider....