SIGN 50: A guideline developer's handbook - Annex C: Methodology Checklist 4: Case-control Studies

Methodology Checklist 4: Case-control 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 an well conducted case control 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 cases and controls are taken from comparable populations	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.3	The same exclusion criteria are used for both cases and controls	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.4	What percentage of each group (cases and controls) participated in the study?	Cases: Controls:
1.5	Comparison is made between participants and non-participants to establish their similarities or differences	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.6	Cases are clearly defined and differentiated from controls	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.7	It is clearly established that controls are non-cases	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Assessment
1.8	Measures will have been taken to prevent knowledge of primary exposure influencing case ascertainment	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
1.9	Exposure status is measured in a standard, valid and reliable way	Well covered Adequately addressed Poorly addressed	Not addressed Not reported Not applicable
Confounding
1.10	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
1.11	Confidence intervals are provided
Section 2: Overall assessment of the study
2.1	How well was the study done to minimise the risk of bias or confounding? 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 by 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 cases?
3.6	What criteria are used to decide who should be controls?
3.7	What exposure or risk factor is investigated in the study? (Include dosage where appropriate)
3.8	How long were patients followed-up for?
3.9	List the key characteristics of the patient population. Note if there are any significant differences between different arms of the trial.
3.10	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.
	Cases: Exposure: Sample size: No. analysed: With outcome: Without outcome:	Cases: Exposure: Sample size: No. analysed: With outcome: Without outcome:
3.11	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]