Question

1. For the following studies, state the study design used by the investigators.

(a) A potential link between occupational exposure to electromagnetic radiation and brain cancer was assessed by selecting 747 people with brain cancer and 1494 people without brain cancer, and then comparing them on past occupational electromagnetic exposure.

(b) The association between periodontal disease and chronic respiratory disease was studied by examining current oral health and lung function in 13792 subjects.

(c) A possible new treatment for high cholesterol was investigated by randomizing 779 patients to take a new medication or placebo for 52 weeks. Low-density lipoprotein (LDL) cholesterol levels were measured at the end of follow-up.

Answer 1

(a)

The study design used by the investigators. : Case Control Experimental Study

Explanation:

In this experimentation, data are obtained from group of people with brain cancer and another group of people without brain cancer are selected and then information is obtained on past occupational electromagnetic exposure.

(b)

The study design used by the investigators. : Cohart Experimental Study

Explanation:

In this study,data on current oral health and lung function are obtained from group whohave been exposed or not exposed to periodontal disease and chronic respiratory disease.

(c)

The study design used by the investigators. : Randomized Controlled Experimental Study

Explanation:

In this experimentation, participants are allocated to treatment or placebo groups using random mechanism.