Critical appraisal:Thompson IM, Pauler DK, Goodman PJ, Tangen CM, Lucia MS, Parnes HL, et al 2004 2

Risk of bias assessment: diagnostic accuracy study

Patient Selection

Prior tests and any referral filters

Condition that defined entry into study

PSA<3.0ng/mL, normal DRE, 55+ years old, AUA symptom score <20

Setting

Multi-centre RCT

Was a diagnostic case-control design avoided?

Yes

Consecutive or random sample?

Yes

Did the study avoid inappropriate exclusions?

Yes

Reasons

Only included those never had a PSA >4.0ng/mL or abnormal DRE and never underwent a prostate biopsy or a transurethral resection of the prostate over the course of the 7-year study

If comparing more than one index test was the design fully paired or paired randomly?

Yes

If a paired randomised design was used, was allocation to groups concealed and was the generation of allocation sequence adequate?

Not applicable

What is the risk that the selection of participants introduced bias?

Low

Comments

Index test 1

Describe index test and how it was conducted and interpreted

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

Not applicable

If two tests are being compared, have they been assessed independently / blind to each other?

Yes

What is the risk that the conduct or interpretation of the index test introduced bias?

Low

Comments

Index test 2

Describe index test and how it was conducted and interpreted, if applicable

Were the index test results interpreted without knowledge of the results of the reference standard?

Yes

If a threshold was used, was it pre-specified?

Not applicable

What is the risk that the conduct or interpretation of the index test introduced bias?

Low

Comments

Reference Standard

Describe the reference standard and how it was conducted and interpreted

Minimum 6 cores

Is the reference standard likely to correctly classify the target condition?

No

Were the reference standard results interpreted without knowedge of the results of the index test/s?

Unclear

Was the reference test standard independent of the index test?
(i.e. the index test did not form part of the reference standard)

Yes

What is the risk that the reference standard, its conduct or interpretation introduced bias?

High

Comments

Flow and timing

Describe any patients who did not receive the index test(s) and/or reference standard or who were excluded from the 2x2 table

Describe the time interval and any interventions between index test(s) and reference standard

PSA test on the day of biopsy but before biopsy or within 90 days before biopsy

If a predictive test (the reference standard is a later event that the test aims to predict) were any subsequent interventions between test and later event blind to test result?

Not applicable

Was there an appropriate interval between index test(s) and reference standard?

Yes

Did either all participants or a random sample of participants receive a reference standard test?

Yes

Did all patients receive the same reference standard irrespective of index test result?

Yes

Were all test results including unclear results reported?

Yes

Were all patients included in the analysis?

No

What is the risk that the patient flow introduced bias?