In conducting a preliminary investigation of an allegation of fraud or abuse and before the allegation may proceed to a full investigation, the office of inspector general must:
(1) review the allegation and all facts and evidence relating to the allegation; and
(2) prepare a preliminary investigation report that documents:
(A) the allegation;
(B) the evidence the office reviewed, if available;
(C) the procedures the office used to conduct the preliminary investigation;
(D) the preliminary investigation findings; and
(E) the office's determination of whether a full investigation is warranted.