–A = Patient has metastatic
cancer
–B = Patient has increased
total serum calcium
–C = Patient has a brain
tumor
–D = Patient lapses
occasionally into coma
–E = Patient has a severe
headache
•What are the direct causal links between these variables?
"Metastatic
cancer is a possible cause of a brain tumor and is also an explanation for increased total serum calcium. In turn, either of these could explain a patient falling into a coma. Severe headache is also possible associated with a brain tumor."
