Critical appraisal:Thompson IM, Ankerst DP, Chi C, Lucia MS, Goodman PJ, Crowley JJ, et al 2005 2
From Cancer Guidelines Wiki
Risk of bias assessment: diagnostic accuracy study
Patient Selection
Prior tests and any referral filters
- prescreened PSA, DRE and AUA score
Condition that defined entry into study
- men with PSA less than or equal to 3ng/mL, normal DRE and AUA score <20 at baseline( approximately 1-7 years prior to biopsy)
Setting
- RCT multicentre 221 centres
Was a diagnostic case-control design avoided?
- Yes
Consecutive or random sample?
- Unclear
Did the study avoid inappropriate exclusions?
- Yes
Reasons
- exclusions men with PSA >3.0 , abnormal DRE or aged <55 years at baseline unlikely to bias results for a pre-screened population
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
- various PSA cut-offs
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?
- Unclear
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
- PSA > 4.0 ng/mL
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?
- Unclear
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
- 84.5% underwent sextant biopsy
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)
(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
- Biopsy may have missed some cancers
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
- all men received index tests and reference standard
Describe the time interval and any interventions between index test(s) and reference standard
- less than 1 year
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?
- Unclear
Were all patients included in the analysis?
- No
What is the risk that the patient flow introduced bias?
- Low
Comments
- Imputed missing data for men who refused biopsy - results very similar to results without imputation off missing data
Overall risk of bias
| At risk of bias | Additional comments: |
Comments
This appraisal has been completed.
- Article
- Thompson IM, Ankerst DP, Chi C, Lucia MS, Goodman PJ, Crowley JJ, et al. Operating characteristics of prostate-specific antigen in men with an initial PSA level of 3.0 ng/ml or lower. JAMA 2005 Jul 6;294(1):66-70 Available from: http://www.ncbi.nlm.nih.gov/pubmed/15998892.
- Assigned to
- User:Suzanne.hughes
- Topic area
- Guidelines:PSA Testing/PSA Protocols
- Clinical question
Section below only relevant for Cancer Council Project Officer
only study where sensitivity and specificity can be assessed with out risk of verification bias