SIGN 50: A guideline developer's handbook - Annex C: Methodology Checklist 5: Studies of Diagnostic Accuracy

Methodology Checklist 5: Studies of Diagnostic Accuracy

This checklist and the associated notes are based on the QADAS tool: Whiting J, Rutjes AW, Dinnes J, Reitsma JB, Bossuyt PM, Kleijnen J. Development and validation of methods for assessing the quality of diagnostic accuracy studies. Health Tech Assess 2004;8(25).
Study identification (Include author, title, reference, year of publication)
Guideline topic:		Key Question No:
Checklist completed by:
SECTION 1: INTERNAL VALIDITY
In a well conducted diagnostic study…		In this study this criterion is
1.1	The spectrum of patients is representative of the patients who will receive the test in practice.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.2	Selection criteria are clearly described.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.3	The reference standard is likely to classify the condition correctly.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.4	The period between reference standard and index test is short enough to be reasonably sure that the target condition did not change between the two tests.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.5	The whole sample, or a random selection of the sample, received verification using a reference standard of diagnosis.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.6	Patients received the same reference standard regardless of the index test result.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.7	The reference standard was independent of the index test (i.e. the index test did not form part of the reference standard).	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.8	The execution of the index test was described in sufficient detail to permit replication of the test.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.9	The execution of the reference standard was described in sufficient detail to permit replication of the test.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.10	Index test results were interpreted without knowledge of the results of the reference standard.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.11	Reference standard results were interpreted without knowledge of the results of the index test.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.12	Uninterpretable or intermediate test results are reported.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.13	An explanation is provided for withdrawals from the study.	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Section 2: OVERALL ASSESSMENT OF THE STUDY
2.1	How reliable are the conclusions of this study? Code ++, +, or -
2.2	Were the same clinical data available when test results were interpreted as would be available when the test is used in practice?
Section 3: description OF THE STUDY (Note: The following information is required for evidence tables to facilitate cross-study comparisons. Please complete all sections for which information is available). PLEASE PRINT CLEARLY
3.1	How many patients are included in this study? Please indicate number of patients included, with inclusion/exclusion criteria used to select them.
3.2	What is the prevalence (proportion of people with the disease being tested for) in the population from which patients were selected?
3.3	What are the main characteristics of the patient population? Include all relevant characteristics – e.g. age, sex, ethnic origin, comorbidity, disease status, community/hospital based
3.4	What test is being evaluated in this study? Consider whether the technology being described is comparable / relevant to the test being considered in the guideline. i.e. make sure the test has not been superceded by later developments.
3.5	What is the reference standard with which the test being evaluated is compared? Indicate whether a gold standard, or if not how this standard was validated.
3.7	What is the estimated sensitivity of the test being evaluated? (state 95% CI) Sensitivity = proportion of results in patients with the disease that are correctly identified by the new test.
3.8	What is the estimated specificity of the test being evaluated? (state 95% CI) Specificity = proportion of results in patients without the disease that are correctly identified by the new test
3.9	What is the positive predictive value of the test being evaluated? Positive predictive value = proportion of patients with a positive test result that actually had the disease.
3.10	What is the negative predictive value of the test being evaluated? Negative predictive value = proportion of patients with a negative test result that actually did not have the disease.
3.11	What are the likelihood ratios for the test being evaluated? If not quoted in the study, a number of tools are available that simplify calculation of LRs. Please indicate where results are calculated rather than taken from the study.
3.12	How was this study funded? List all sources of funding quoted in the article, whether Government, voluntary sector, or industry.
3.13	Are there any specific issues raised by this study?

[SIGN 50 Annex C] [Notes on use of checklist]