Developing a good review question/objective is an important step in undertaking a quality systematic review as it sets out the key components of the review (i.e. population, index test, reference test, objectives).
An example of a well written review objective is “To determine the diagnostic accuracy of currently available laboratory tests for swine flu (H1N1) using viral culture as a reference test amongst people presenting with suspected flu” which could alternatively be phrased as the question “What is the diagnostic accuracy of currently available laboratory tests for swine flu (H1N1) compared to viral culture as a reference test amongst people presenting with suspected flu?”