Critical appraisal:Carvalho R, Areia M, Brito D, Saraiva S, Alves S, Cadime AT 2013 1 2

Risk of bias assessment: cohort study (risk factors)

Bias in selection of participants into study

Selection of the exposed and non-exposed cohorts

Drawn from the same population (low risk)

Bias due to error in exposure measurement

Measurement of exposure

Objective measurements from pre-existing records or <img alt="File:Jutta's info icon.png" src="/australiawiki_test/images/d/d9/Jutta%27s_info_icon.png" width="16" height="16"> baseline (Existing at or before baseline, where baseline is the time at which a participant is recorded to have entered the cohort or, if obtained after baseline, before onset of symptoms of the outcome or any likely effect of the developing outcome on the exposure) physical or biological assessment not blind to outcome status, OR structured interview (moderate risk)

Bias due to error in outcome measurement

Measurement of outcome

Outcome measurement unlikely to be influenced by exposure (low risk)

Was outcome of interest absent at the time to which the exposure refers?

Yes (low risk)

Was follow-up long enough for outcome to occur as a consequence of measured exposure? (Requires prior specification of a sufficient follow-up period)

Yes (low risk)

Bias due to non-participation

Participation rate in cohort

Participation rate in exposed cohort ≤10 percentage points different from non-exposed cohort OR exposed and non-exposed are from the same cohort (low risk)

Bias due to missing data

Completeness of follow-up of cohort

Active or passive follow-up with methods for ascertainment of one or more of outcome, death or emigration not described OR there was probably < 70% follow-up OR insufficient information to tell (high risk)

Accuracy of dates of outcome or censoring

Dates of outcome or censoring ascertained to within one year (low risk)

Difference in follow-up between exposed and non-exposed members of cohort

Follow-up methods are the same and likely to achieve the same completeness of follow-up in exposed and non-exposed participants (low risk)

Difference in missing data for exposure between those with or without the outcome

Difference in missing data for exposure ≥20 percentage points OR insufficient information to tell (high risk)

Bias due to confounding

Comparability of exposed and non-exposed cohorts with respect to potentially important confounding variables (Requires prior specification of potentially important confounders)

Age and other potentially important confounders measured and controlled by design or in analysis (low risk)

Analysis bias

Covariates are appropriately included in statistical analysis models

Variables measuring the same underlying concept or lying in the same causal pathway ARE NOT included together as covariates in statistical analysis models (low risk)

Overall risk of bias

High 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

Carvalho R, Areia M, Brito D, Saraiva S, Alves S, Cadime AT. Endoscopic mucosal resection of large colorectal polyps: prospective evaluation of recurrence and complications. Acta Gastroenterol Belg 2013 Jun;76(2):225-30 Available from: http://www.ncbi.nlm.nih.gov/pubmed/23898560.

Assigned to

User:Albert.chetcuti

Topic area

Guidelines:Colorectal cancer/Colonoscopy surveillance

Clinical question

• What is the appropriate colonoscopic surveillance after the removal of large sessile or laterally spreading adenomas?

Form

Form:Quality appraisal cohort risk factors

Outcomes

surveillance

Section below only relevant for Cancer Council Project Officer

Edit appraisal assignment