How to Read a Paper

BMJ Qualitative Research papers -Tricia Greenalgh

 

Assessing Methodological Quality

When analyzing a paper for its methological value, a number of questions may be considered:

 

1) Was the study original?

2) Who is the study about?

3) Was the study design sensible?

4) Was clinical bias avoided or minimized?

5) Was assessment 'blind'?

 

6) Were preliminary statistical questions dealt with?

 

 

 

Study Validity

There are many things that can erode a study's validity.

 

Accuracy

One of the most significant is the study's accuracy - the degree to which the study's findings are free from error. Accuracy involves two components:

Precision/Reliability

Validity

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Bias

Bias is the systematic deviation from truth due to any trend in the collection, analysis, interpretation, publication, or review of data

selection bias

measurement bias

controlling bias

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Confounding

Confounding is the confusion of the effects of variables, where an additional variable may be responsible for an apparent assication or outcome. Confounding leads to systematic error, and is actually a form of bias.

 

Methods for Controlling for Confounding

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Standardization

A technique for removing, as much as possible, the effects of differences in confounding variables when comparing two or more populations.

Standardization is an adjustment of the crude rate of a health-related event to a rate comparable with a standard population.

 

 

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Event Modifiers

Event modifiers are third variables that aliter the direction or strength of association between two other variables. They are useful things to know and should be looked for

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