A researcher is studying the likely occurrence rate of secondary cancers after a new schedule of chemotherapy for childhood leukemia, using a biochemical marker obtained by blood draw six months after the initiation of chemotherapy

Question

What is the rationale for using this marker as a proximate outcome, rather than counting the actual rate of secondary cancers?
a. Research on recurrent cancers in children labels them as vulnerable, causing psychological harm.
b. The final endpoint is not obtainable over a reasonable span of time, since secondary cancers can occur at any age.
c. Most proximate endpoints are unreliable variables and should not be used unless there are no final endpoints.
d. The researcher is not interested in whether children suffer a secondary malignancy; the researcher is merely interested in the marker value.

Answer 1

ANS: B
At the outset of a research project, there may be as yet little scientific basis for judging the precise relationship between factors and outcome. Many of the influencing factors may be outside the jurisdiction or influence of the healthcare system or of the providers within it, occurring much later in time, when subjects have been lost to follow-up. One solution to this problem of identifying relevant outcomes is to define a set of proximate outcomes specific to the condition for which care is being provided. Critical pathways and care maps may help the researcher to define at least proximate outcomes.