Other of Audit, Review and Assurance Engagements .. 6 6. Assume that repatriation hospitals do not collect data on bed days by principal diagnosis. What courses Of 7, Assume sufficient, appropriate audit evidence has been gathered in relation to all relevant criteria described CASE 6-4 OPQ LIMITED Source: This case was adapted from 1990 (2) Audit module material in the CA Program of the ICAA and modified for current standards on audit, review and assurance engagements. STANDARDS ISA/ ASA 200 ISA/ASA 500 ISRE/ASRE 2400 LEVEL OF DIFFICULTY Medium SUBJECT MATTER Due diligence engagement Audit plan Analytical procedures Audit evidence