Final answer:
A differential diagnosis is a systematic method used to identify the possible conditions causing a patient's symptoms. X-rays and blood tests differentiate between osteoarthritis and rheumatoid arthritis. Objective findings from tests often take precedence over subjective clinical signs in making a medical diagnosis.
Step-by-step explanation:
A differential diagnosis (D/DX), or rule out (R/O), is a clinical tool used by healthcare providers to identify the possible conditions that might be causing a patient's symptoms and to systematically exclude each potential cause. In the context provided, X-rays and blood tests are utilized to differentiate between osteoarthritis (OA) and rheumatoid arthritis (RA), which are two distinct conditions with overlapping symptoms but different treatment approaches.
When both clinical signs (sx) and objective findings (o, such as X-rays) are available, preference is often given to objective findings, because they can provide conclusive evidence supporting or excluding a diagnosis. If blood tests show no indicators of RA, then the diagnosis of OA becomes more plausible, and the treatment will focus on managing the symptoms of OA, often involving pain relievers, physical therapy, and lifestyle changes.