Diagnostic-accuracy reports
A diagnostic accuracy study compares an index test with a reference standard. Its report identifies the study as one of diagnostic accuracy, describes the participants, the tests and the analysis, gives the estimates of diagnostic accuracy with their precision, and sets the findings against the intended use and clinical role of the index test.
STARD 2015, an updated list of essential items for reporting diagnostic accuracy studies, recommends that the report of such a study do the following.
Title, abstract and background
Identify the study in the title or abstract as a study of diagnostic accuracy, using at least one measure of accuracy, such as sensitivity, specificity, predictive values or the area under the curve. Give a structured summary of the study design, methods, results and conclusions, which may include study aims such as estimating diagnostic accuracy or comparing accuracy between tests or across participant groups. Give the scientific and clinical background, including the intended use and clinical role of the index test, and the study objectives and hypotheses.
Study design and participants
State whether data collection was planned before the index test and the reference standard were performed, as a prospective study, or after them, as a retrospective study. Give the eligibility criteria and the basis on which potentially eligible participants were identified, such as symptoms, results from previous tests or inclusion in a registry.
Test methods
Describe the index test and the reference standard in sufficient detail to allow replication. Define the test positivity cutoffs or result categories of each and give the rationale for them, distinguishing prespecified from exploratory ones. State whether clinical information and the results of the reference standard were available to the people performing or reading the index test.
Analysis
Give the intended sample size and how it was determined, and the methods for estimating or comparing measures of diagnostic accuracy. Say how indeterminate results and missing data on the index test and the reference standard were handled, and report any analyses of variability in diagnostic accuracy, distinguishing prespecified from exploratory ones.
Participants and test results
Show the flow of participants in a flow diagram, and report their baseline demographic and clinical characteristics, the distribution of disease severity in those with the target condition and of alternative diagnoses in those without it, and the interval and any clinical interventions between the index test and the reference standard. Present the cross-tabulation of the index test results, or their distribution, by the results of the reference standard, the estimates of diagnostic accuracy with their precision, such as 95% confidence intervals, and any adverse events from performing the index test or the reference standard.
Limitations and implications for practice
Discuss the study's limitations, including sources of potential bias, statistical uncertainty and generalizability, and the implications for practice, including the intended use and clinical role of the index test.
Registration, protocol and funding
Give the registration number and the name of the registry, the place where the full study protocol can be accessed, and the sources of funding and other support, with the role of the funders.