Table 4 STARD (STAndards for the Reporting of Diagnostic accuracy studies) checklist

Title/Abstract/Keywords

1

Identify the article as a study of diagnostic accuracy (recommend MeSH heading “sensitivity and specificity”).

1–3

Introduction

2

State the research questions or study aims, such as estimating diagnostic accuracy or comparing accuracy between tests or across participant groups.

4–5

Methods

 Participants

3

The study population: The inclusion and exclusion criteria, setting and locations where data were collected.

5–7

4

Participant recruitment: Was recruitment based on presenting symptoms, results from previous tests, or the fact that the participants had received the index tests or the reference standard?

5–7

5

Participant sampling: Was the study population a consecutive series of participants defined by the selection criteria in item 3 and 4? If not, specify how participants were further selected.

7

6

Data collection: Was data collection planned before the index test and reference standard were performed (prospective study) or after (retrospective study)?

7

 Test methods

7

The reference standard and its rationale.

7–8

8

Technical specifications of material and methods involved including how and when measurements were taken, and/or cite references for index tests and reference standard.

8–9

9

Definition of and rationale for the units, cutoffs and/or categories of the results of the index tests and the reference standard.

7–9

10

The number, training, and expertise of the persons executing and reading the index tests and the reference standard.

8–9

11

Whether or not the readers of the index tests and reference standard were blind (masked) to the results of the other test and describe any other clinical information available to the readers.

N/A

 Statistical methods

12

Methods for calculating or comparing measures of diagnostic accuracy, and the statistical methods used to quantify uncertainty (e.g., 95 % confidence intervals).

9, 10, Appendix 3

13

Methods for calculating test reproducibility, if done.

N/A

Results

 Participants

14

Report when study was done, including beginning and ending dates of recruitment.

9, Additional file 1: Figure S1

15

Report clinical and demographic characteristics of the study population (e.g., age, sex, spectrum of presenting symptoms, comorbidity, current treatments, recruitment centers).

10, Table 1

16

Report the number of participants satisfying the criteria for inclusion that did or did not undergo the index tests and/or the reference standard; describe why participants failed to receive either test (a flow diagram is strongly recommended).

Additional file 1: Figure S1

 Test results

17

Report time interval from the index tests to the reference standard, and any treatment administered between.

10

18

Report distribution of severity of disease (define criteria) in those with the target condition; other diagnoses in participants without the target condition.

10, Table 1

19

Report a cross tabulation of the results of the index tests (including indeterminate and missing results) by the results of the reference standard; for continuous results, the distribution of the test results by the results of the reference standard.

10–11, Table 2, Table 3

20

Report any adverse events from performing the index tests or the reference standard.

N/A

 Estimates

21

Report estimates of diagnostic accuracy and measures of statistical uncertainty (e.g., 95 % confidence intervals).

10–11, Table 2, Table 3, Additional file 1: Figure S2 and S3

22

Report how indeterminate results, missing data, and outliers of the index tests were handled

N/A

23

Report estimates of variability of diagnostic accuracy between subgroups of participants, readers or centers, if done

N/A

24

Report estimates of test reproducibility, if done.

N/A

Discussion

25

Discuss the clinical applicability of the study findings

15