Answer:
PICO is a mnemonic system that is much used in evidence-based practice both in Medicine and Nursing. This system allows a researcher in a medical field to evaluate all aspects of a situation, or health condition, being studied and respond to all the necessary questions in an organized and integral form. PICO, stands for the following: P: patient, problem or population, I: Intervention, C: Comparisson, control, and O: Outcomes.
In the case of this question, the nurse researcher wishes to ascertain the effectiveness of replacing intravenous catheters in patients with a frequency of 72 hour-intervals between changes in diminishing infection rates due to this nursing procedure. In order to fully research the validity of such a question, of the ensuing experimentation, observation and gathering of data, and the release of valid results, this researcher will use PICO as her guiding framework. As the question requests, then, the O in this system would apply to the expected result, or the outcome, expected from applying the thesis of the researcher. That would be: "the decrease infection rates."