Question

A study comparing smokers to non-smokers history as a risk factor for Parkinson's Disease reports an incidence rate ratio of 0.3 comparing smokers to non-smokers. Explain your answers. 1) What is the study design? 2) If the association is real, do these findings indicate an increase or decrease in risk for Parkinson's disease? 3) A case-control study comparing Alzheimer's cases to controls reported cases were less likely to have reported past smoking. What kind of bias may explain these results?

Answer 1

1. The study design is prospective observational study. this study is carried out in a group of people who have parkinsons disease. The comparision done between the smokers and non smokers who are at more risk.

2. The findings indicate an increase in the risk of parkinsons disease in the people who have a habit of smoking.

3.in this case control study the patients with alzheimers are compared with controllers that is who do not have alzheimersdisease. but are having a past history of smoking.by comparing them we can acquire the results like does smoking can cause alzheimers or can smoking can increase the risk of alzheimers.or the risk of smoking in alzheimers patients are compared with the risk of smoking in controlls.