The physician assistant board shall complete a preliminary investigation of a complaint filed with the physician assistant board not later than the 30th day after the date of receiving the complaint. The physician assistant board shall first determine whether the physician assistant constitutes a continuing threat to the public welfare. On completion of the preliminary investigation, the physician assistant board shall determine whether to officially proceed on the complaint. If the physician assistant board fails to complete the preliminary investigation in the time required by this section, the physician assistant board’s official investigation of the complaint is considered to commence on that date.