Title “Intake of dairy foods and risk of Parkinsondisease”
- What was the primary scientific objective of the study? Wasthis clearly stated? If not, what do you think the authors intendedto be the primary objective?
The primary scientific objective ofthe study is to prospectively examine the association betweencommonly consumed dairy products and the risk of Parkinson disease(PD) in women and men. Yes, it has been clearly stated.
- What were the authors’ major conclusion(s)? Did they addressthe study objectives?
The author’s major conclusion was frequently consumption of dairyproducts appears to be associated with a modest increased risk ofPD in women and men. The conclusion address the studyobjective.
- What was the exposure of interest? What was the main exposurevariable (if there were many, pick one)? Do you think theexposure variable was a good measure of the exposureof interest? Critique this exposure variable in terms of:differential and non-differential exposure misclassification,interpretability and relevance to the primary objective of thestudy.
4. What was the outcome of interest? What was the main outcomevariable (if there were many, pick one)? Do you think thisoutcome variable was a good measure of the outcome ofinterest? Critique this outcome variable in terms of:differential and non-differential outcome misclassification,interpretability and relevance to the primary objective of thestudy.
5. What was the study design? What was the studypopulation?
a. Critique the design. Do you think there is an alternative thatwould have been better?
b. Critique the choice of study population. Could it have beenimproved?
6. Was there any important potential bias in the way the groupswere:
a. selected (selection bias) or
b. in the way the information was collected (informationbias)?
Indicate and explain the likely direction(s) of important biases,i.e., whether their effects would probably have biased the resultstowards or away from the null.
7. What did the authors do to investigate and/or controlconfounding in:
a. the design of the study and
b. the analysis of the study?
Did they miss any important confounders? Do you think there isimportant residual confounding in the results?
8. What do you consider to be the primary weakness of the study?Is this weakness sufficient to eliminate it from your evaluation ofevidence relevant to the study hypothesis?
