Critical appraisal:Chowdhury ATMD, Longcroft-Wheaton G, Davis A, Massey D, Goggin P 2014
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Risk of bias assessment: diagnostic accuracy study
Patient Selection
Prior tests and any referral filters
- IDA screening.
Condition that defined entry into study
- Referral for an IDA investigation.
Setting
- Single secondary care hospital in the UK.
Was a diagnostic case-control design avoided?
- Yes
Consecutive or random sample?
- Unclear
Did the study avoid inappropriate exclusions?
- Yes
Reasons
If comparing more than one index test was the design fully paired or paired randomly?
- Not applicable
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?
- Unclear
Comments
Index test 1
Describe index test and how it was conducted and interpreted
- All participants had an MCV <82 with a serum ferritin <12.
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?
- Yes
If two tests are being compared, have they been assessed independently / blind to each other?
- No
What is the risk that the conduct or interpretation of the index test introduced bias?
- High
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?
- Not applicable
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?
- Not applicable
Comments
Reference Standard
Describe the reference standard and how it was conducted and interpreted
Is the reference standard likely to correctly classify the target condition?
- Yes
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?
- Unclear
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
- 25 participants failed to complete tests.
Describe the time interval and any interventions between index test(s) and reference standard
- Not described.
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?
- Unclear
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?
- High
Comments
Overall risk of bias
| At risk of bias | Additional comments: Please replace this text and include any additional comments in regards to your risk of bias rating |
This appraisal has been completed.
- Article
- Chowdhury ATMD, Longcroft-Wheaton G, Davis A, Massey D, Goggin P. Role of faecal occult bloods in the diagnosis of iron deficiency anaemia. Frontline Gastroenterology 2014 Oct 1;5(4):231-36.
- Assigned to
- User:Ben.lee-bates
- Topic area
- Guidelines:Colorectal cancer
- Clinical question
- Form
- Form:Quality appraisal quadas
- Outcomes
- Positive predictive values
Section below only relevant for Cancer Council Project Officer