How is ' Rule-out ' used in a Health-related Memorandum

Per DepEd Memo No. 0146 s. 2015 , rule-out was used as:

" Fear of injections resulting to fainting has been commonly observed in school immunization. Thus, it is recommended that vaccination sites are situated in areas not conspicuous to the students. Immunization sessions shall be conducted after recess to ensure eligible students have taken their snacks/ food to rule- out fainting secondary to hypoglycemia."

Thus, rule-out is used to indicate that the symptom/s  is/are not caused by or should no longer be attributed to a certain condition based on the assessment or interventions done.