Soru

A 60-year-old man with a long-standing history of poorly controlled rheumatoid arthritis presents to the ambulatory clinic reporting worsening fatigue and a $4 \text{ kg}$ ($8.8 \text{ lb}$) unintentional weight loss over the past 3 months. Physical examination reveals active synovitis in the metacarpophalangeal and proximal interphalangeal joints bilaterally. The evaluating physician quickly concludes that the patient is experiencing a severe rheumatoid flare causing systemic symptoms.

Laboratory studies obtained at the visit reveal the following:

Hemoglobin: $8.9 \text{ g/dL}$
Mean corpuscular volume: $72 \text{ fL}$
Ferritin: $11 \text{ ng/mL}$ (normal: $30-400 \text{ ng/mL}$)

Despite the markedly low ferritin level pointing toward absolute iron deficiency (such as from occult gastrointestinal bleeding), the physician documents that the laboratory findings are 'highly consistent with anemia of chronic disease secondary to active rheumatoid inflammation.' The physician increases the dose of the patient's immunosuppressive therapy and schedules a follow-up in three months, without initiating a gastrointestinal evaluation. Nine months later, the patient is diagnosed with metastatic ascending colon cancer.

Which of the following cognitive biases most directly led the physician to interpret the conflicting laboratory data as supportive of the initial hypothesis?