The essence of the objective should be captured in the review’s title. Typically this involves stating the diagnostic technology together with the key characteristics of the people to whom it is applied and the purpose for which it is used. The key components of the title are therefore:
the patients (how they present, where they present to, what tests have been done before);
the target condition (disease, disease stage, or sub-type of a disease eligible for a specific treatment);
the test or tests being evaluated.
The test that is being evaluated is known as the index test. A review may evaluate and compare the diagnostic accuracy of several index tests, and may elect one as a comparator test with which the diagnostic accuracy of the other index tests is compared, particularly if this test is currently standard diagnostic practice. The target condition is the condition of interest that the index and comparator test(s) are attempting to detect. The clinical reference standard is usually the test or tests representing the best available method of detecting the target condition. Reference standards, which give results with very little error, are known as ‘gold standards’. Please note the difference between the reference standard and the comparator test: the reference standard is the best test available to detect the target condition (and may not routinely be used in clinical practice) while the comparator test is a routinely used test, the diagnostic accuracy of which we wish to compare with other index tests to decide which is the best for detecting the target condition.
The review title in RevMan5 is structured to ensure that the correct information is reported to reflect the objective of the review for example, “What is the diagnostic accuracy of ‘index test’ for diagnosing ‘target condition’ in ‘patient description’?” Four title options are possible (Table 4.2.a). These vary in the number of tests being evaluated (options 1 and 2 are for two tests, options 3 and 4 work for either a single test or several tests), and whether the patient description is required (options 1 and 3). Options 2 and 4, which do not include the patient description, should only be used where the target condition clearly implies a particular patient group.
Table 4.2.a: Structure for titles of Cochrane systematic reviews of diagnostic test accuracy
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Option 1 |
Format |
<Index test 1> versus <index test 2†> for <target condition(s)> in <patient description> |
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Example |
<Chlamydia antibody titre testing> versus <hysterosalpingography> for diagnosing <tubal pathology> in <subfertile women> |
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Option 2 |
Format |
<Index test 1> versus <index test 2†> for <target condition(s)> |
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Example |
<MRI> versus <ultrasound> for diagnosing <ischaemic stroke> |
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Option 3 |
Format |
<Index test(s)> for <target condition(s)> in <patient description> |
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Example |
<Physical examination> for the diagnosis of <lumbar radiculopathy due to disc herniation> in <patients with low back pain> |
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Option 4 |
Format |
<Index test(s)> for <target condition(s)> |
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Example |
<Physical tests> for <detection of shoulder impingements> |
† if the comparison is with current diagnostic practice, the second index test will be the comparator test |