Question :1. An investigator wants to assess whether smoking is a risk factor for pancreatic cancer. Electronic medical records at a local hospital will be used to identify fifty patients with pancreatic cancer. One hundred patients who are similar but free of pancreatic cancer will also be selected. Each participant's medical record will be analyzed for smoking history. Identify the type of study proposed and indicate its specific strengths and weaknesses.
Type of study:
Strengths:
Weaknesses:
2. A study is planned to assess the effect of a new surgical intervention for gallbladder disease. One hundred patients with gallbladder disease will be randomly assigned to receive either the new surgical intervention or the standard surgical intervention. The efficacy of the new surgical intervention will be measured by the time is takes a patient to return to normal activities, measured in days. Identify the type of study proposed and indicate its specific strengths and weaknesses.
Type of study:
Strengths:
Weaknesses:
3. In 1940, 2,000 women working in a factory were recruited into a study. Half of the women worked in manufacturing and half in administrative offices. The incidence of bone cancer through 1970 among the 1,000 women working in manufacturing was compared with that of 1,000 women working in administrative offices. Thirty of the women in manufacturing developed bone cancer as compared to 9 of the women in administrative offices. This study is an example of a:
a. randomized controlled trial
b. case-control study
c. cohort study
d. crossover trial
4. A study is designed to evaluate the impact of a daily multivitamin on students' academic performance. One hundred sixty students are randomly assigned to receive either the multivitamin or a placebo and are instructed to take the assigned drug daily for 20 days. On day 20, each student takes a standardized exam and the mean exam scores are compared between groups. This study is an example of a:
a. randomized controlled trial
b. case-control study
c. cohort study
d. crossover trial