SIGN 50: A guideline developer's handbook - Annex C: Methodology Checklist 3: Cohort Studies

Methodology Checklist 3: Cohort Studies

Study identification (Include author, title, year of publication, journal title, pages)
Guideline topic:			Key Question No:
Checklist completed by:
Section 1: Internal validity
In a well conducted cohort study:			In this study the criterion is:
1.1	The study addresses an appropriate and clearly focused question.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Selection of subjects
1.2	The two groups being studied are selected from source populations that are comparable in all respects other than the factor under investigation.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.3	The study indicates how many of the people asked to take part did so, in each of the groups being studied.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.4	The likelihood that some eligible subjects might have the outcome at the time of enrolment is assessed and taken into account in the analysis.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.5	What percentage of individuals or clusters recruited into each arm of the study dropped out before the study was completed.
1.6	Comparison is made between full participants and those lost to follow up, by exposure status.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Assessment
1.7	The outcomes are clearly defined.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.8	The assessment of outcome is made blind to exposure status.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.9	Where blinding was not possible, there is some recognition that knowledge of exposure status could have influenced the assessment of outcome.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.10	The measure of assessment of exposure is reliable.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.11	Evidence from other sources is used to demonstrate that the method of outcome assessment is valid and reliable.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.12	Exposure level or prognostic factor is assessed more than once.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Confounding
1.13	The main potential confounders are identified and taken into account in the design and analysis.		Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Statistical analysis
1.14	Have confidence intervals been provided?
Section 2: Overall assessment of the study
2.1	How well was the study done to minimise the risk of bias or confounding, and to establish a causal relationship between exposure and effect? Code ++, +, or -
2.2	Taking into account clinical considerations, your evaluation of the methodology used, and the statistical power of the study, are you certain that the overall effect is due to the exposure being investigated?
2.3	Are the results of this study directly applicable to the patient group targeted in this guideline?
Section 3: Description of the study (Note: the following information is required for evidence tables to facilitate cross-study comparisons. Please complete all sections for which information is available). Please print clearly
3.1	Do we know who the study was funded by?		[ ] Academic Institution [ ] Healthcare Industry [ ] Government [ ] NGO [ ] Public funds [ ] Other
3.2	How many centres are patients recruited from?
3.3	From which countries are patients selected? (Select all those involved. Note additional countries after “Other”)		[ ] Scotland [ ] UK [ ] USA [ ] Canada [ ] Australia [ ] New Zealand [ ] France [ ] Germany [ ] Italy [ ] Netherlands [ ] Scandinavia [ ] Spain [ ] Other:
3.4	What is the social setting (ie type of environment in which they live) of patients in the study?		[ ] Urban [ ] Rural [ ] Mixed
3.5	What criteria are used to decide who should be INCLUDED in the study?
3.6	What criteria are used to decide who should be EXCLUDED from the study?
3.7	What intervention or risk factor is investigated in the study? (Include dosage where appropriate)
3.8	What comparisons are made in the study? (ie what alternative treatments are used to compare the intervention with?). Include dosage where appropriate.
3.9	What methods were used to randomise patients, blind patients or investigators, and to conceal the randomisation process from investigators?
3.10	How long did the active phase of the study last?
3.11	How long were patients followed-up for, during and after the study?
3.12	List the key characteristics of the patient population. Note if there are any significant differences between different arms of the trial.
3.13	Record the basic data for each arm of the study. If there are more than four arms, note data for subsequent arms at the bottom of the page
	Arm 1: Treatment: Sample size: No. analysed With outcome: Without outcome:	Arm 2: Treatment: Sample size: No. analysed With outcome: Without outcome Primary outcome?	Arm 3: Treatment: Sample size: No. analysed With outcome: Without outcome Primary outcome?	Arm 4: Treatment: Sample size: No. analysed With outcome: Without outcome Primary outcome?
3.14	Record the basic data for each IMPORTANT outcome in the study. If there are more than four, not data for additional outcomes at the bottom of the page.
	Outcome 1: Value: Measure: P value Upper CI Lower CI Primary outcome?	Outcome 2: Value: Measure: P value Upper CI Lower CI Primary outcome?	Outcome 3: Value: Measure: P value Upper CI Lower CI Primary outcome?	Outcome 4: Value: Measure: P value Upper CI Lower CI Primary outcome?
3.15	Notes. Summarise the authors conclusions. Add any comments on your own assessment of the study, and the extent to which it answers your question. {Much of this is likely to be contributed by GDG members).

[SIGN 50 Annex C] [Notes on use of checklist]