Study identification (Include author, title, year of publication, journal title, pages)

Guideline topic:

Key Question No:

Checklist completed by:

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

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?

3.1

How many patients are included in this study?

List the number cases and controls separately

3.2

What are the main characteristics of the study population?

Include all characteristics used to identify both cases and controls – e.g. age, sex, social class, disease status

3.3

What environmental or prognostic factor is being investigated in this study?

3.4

What comparisons are made in the study?

Normally only one factor will be compared, but in some cases the extent of exposure may be stratified – e.g. non-smokers v. light, moderate, or heavy smokers. Note all comparisons here.

3.5

For how long are patients followed-up in the study?

Length of time participant histories are tracked in the study.

3.6

What outcome measures are used in the study?

List all outcomes that are used to assess the impact of the chosen environmental or prognostic factor.

3.7

What size of effect is identified in the study?

Effect size should be expressed as an odds ratio. If any other measures are included, note them as well. Include p values and any confidence intervals that are provided.

3.8

How was this study funded?

List all sources of funding quoted in the article, whether Government, voluntary sector, or industry.

3.9

Does this study help to answer your key question?

Summarise the main conclusions of the study and indicate how it relates to the key question.?