EPIB Exam 2 Practice Questions with Complete Solutions Which of the following studies does NOT use individuals as the unit of analysis? - Correct Answer ecological study NAME THAT STUDY: A community assesses a random sample of its residents by telephone questionnaire. Participants are asked to report their height, weight and the presence of any current health conditions (e.g., hypertension, diabetes). Findings indicate that obesity is strongly associated with diagnosed diabetes. - Correct Answer cross-sectional T/F: Loss to follow up can be a problem in cohort studies but not experimental studies. - Correct Answer false Name that study design: In 1995 researchers obtained the personnel and health records from two large insulation factories in the southeastern U.S. The records showed that between 1951 and 1955 there were 825 workers employed at Factory A, and 700 workers employed at Factory B.Between1951-1994 there were 26 deaths from lung cancer among the workers from Factory A, where asbestos was used in production. During the same time period there were only six lung cancer deaths, among the workers from Factory B, where asbestos was not used in production. The investigators hypothesized that exposure to asbestos was associated with an increased risk of lung cancer. - Correct Answer retrospective cohort study Name that study design: To see if hypnosis could reduce chronic pain, investigators randomly assigned 120 volunteers with osteoarthritis to either hypnosis therapy or standard treatment. Pain levels were checked among the subjects every three months during the 12-month study using validated pain measures. Those assigned to the hypnosis group reported reduced pain compared to those in the standard treatment group after three and six months, but not after nine and 12 months of follow up. - Correct Answer randomized controlled trial name that study design: A study was undertaken to test the hypothesis that chewing tobacco increases the risk of stomach cancer. Detailed historical data on chewing tobacco use was collected from 400 subjects with newly diagnosed stomach cancer and 400 subjects without stomach cancer.Participants without stomach cancer were matched to those with cancer on background characteristics such as age, race/ethnicity and gender. The results revealed that chewing tobacco was not a significant risk factor for stomach cancer. - Correct Answer case-control study name that study design: An epidemiologist tested the hypothesis that vitamin D (i.e., the "sunshine" vitamin) is associated with reduced levels of ovarian cancer using data from 12 geographic regions in Sweden. The association was measured using the average annual number of days of sunlight and the rate of ovarian cancer in each region. The findings indicated that the regions with the highest 1 / 2
average days of sunlight per year had significantly lower rates of ovarian cancer than those regions with the fewest average days of sunlight per year. The epidemiologist reported her findings at the Scandinavian Conference on Cancer - Correct Answer ecological study name that study design: Study investigators invited all male physicians in the UK to fill out questionnaires regarding their health status and their smoking status. They then focused on the healthy physicians who were willing to participate and mailed follow-up questionnaires to them every 2 years. Using death certificate data the researchers noted the cause of death for any subjects who became ill and died. The study continued for 50 years - Correct Answer prospective cohort study Which of the following is NOT a purpose of randomization? - Correct Answer To match on exposure purposes of randomization - Correct Answer To ensure that treatment is assigned in an unbiased fashion To ensure comparability between treatment groups To minimize confounding Which of the following is NOT an advantage of randomization? - Correct Answer It can minimize loss to follow-up advantages of randomization - Correct Answer It can control for known confounders It can control for unknown confounders It can ensure comparability between study groups The Behavioral Risk Factor Surveillance System (BRFSS) collects information on health risks and behaviors annually, through a random digit-dialing system every year.What kind of study design is this? - Correct Answer Cross-Sectional Study The Nurses' Health Study is a prospective cohort study that follows female nurses, aged 25-42. Which of the following techniques does this study use to minimize confounding? - Correct Answer Restriction
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