HSC 404 Exam 2 Questions and Correct Answers, With Complete Solution, 2024.

HSC 404 Exam 2 Questions and Correct Answers, With Complete Solution, 2024. Choose the INCORRECT answer regarding ecologic studies: A. An ecologic study is one that examines a group as a unit of analysis B. An ecologic comparison study is sometimes called a cross-sectional ecological study C. The level of exposure for each individual in the unit studied is well known D. The ecologic fallacy occurs when incorrect inferences about the individual are made from group level data C. The level of exposure for each individual in the unit studied is well known Ecologic studies: A. are expensive and require a great deal of time to conduct B. are a good approach for generating hypotheses C. provide accurate measurements of exposure D. yield results that can be applied directly to individuals B. are a good approach for generating hypotheses Cross sectional studies are: A. also termed prevalence studies B. Exposure and disease measures obtained at the individual level C. Single period of observation D. Exposure and disease histories are collected simultaneously E. All of the above E. All of the above In case-control studies, the odds ratio is used as an estimate of the relative risk. In order for this approximation to be reasonable, some conditions must be met. Which of the following condition is not necessary is order to use the odds ratio to estimate the relative risk? A. With respect to exposure, controls are representative of the population to which you want to generalize your results. B. The event (disease) under study is rare in the population. C. The exposure in question is rare in the population. D. Cases are representative of all cases. C. The exposure in question is rare in the population. Cohort study is to risk ratio as: A. ecologic fallacy is to cross-sectional study B. genetics is to environment C. case-control is to odds ratio D. A and C C. case-control is to odds ratio Practical considerations in the design of cohort studies do not usually include: A. availability of exposure data B. size and cost of the cohort C. follow-up issues D. scientific justification E. age of the investigator E. age of the investigator A five year prospective cohort study has just been completed. The study was designed to assess the association between supplemental vitamin A exposure and mortality and morbidity for measles. The RR for incidence of measles was 0.75 and the RR for measles mortality was 0.5. Which statement is correct? A. A cohort study is not an appropriate study design in this case because the association between one exposure and two different outcomes is being considered. B. One of the problems that this study may have faced is individuals lost to follow-up during the 5 year period C. A cohort study is not a good design to study this association because measles is a very common disease. B. One of the problems that this study may have faced is individuals lost to follow-up during the 5 year period Regarding the RR reported above, which statement is correct? A. Exposure to vitamin A appears to protect against morbidity and mortality for measles B. Exposure to vitamin A appears to be a risk factor for morbidity and mortality for measles. C. Exposure to vitamin A is not associated with morbidity and mortality for measles. D. Exposure to vitamin A is a risk factor for morbidity and a protective factor for mortality for measles. A. Exposure to vitamin A appears to protect against morbidity and mortality for measles A major advantage for cohort studies over case-control studies with respect to the role of a suspected factor in the etiology of a disease is that: A. they take less time and are less costly. B. they can utilize a more representative population. C. it is easier to obtain controls that are not exposed to the suspected factor. D. they permit direct estimation of risk of disease in those exposed to the suspected factor. E. they can be done on a double-blind basis. D. they permit direct estimation of risk of disease in those exposed to the suspected factor. Subjects for an exposure-based cohort study would be selected most appropriately from: A. certain occupational groups such as battery workers B. the residents of a large U.S. county C. A and B D. All of the above A. certain occupational groups such as battery workers Nested case-control studies: A. use subjects drawn from a cohort study B. provide a degree of control over confounding C. reduce the cost of collecting exposure information D. all of the above D. all of the above An example of passive follow-up in cohort studies is: A. collection and maintenance of data by the federal government B. telephone calls to study participants C. use of follow-up mailings D. use of written invitations to return to the study site A. collection and maintenance of data by the federal government A prophylactic trial is designed to: A. Compare rates of disease, death, and recovery in a population B. Measure how well drugs produce improvement in patient's illness C. Evaluate the effectiveness of a substance used to prevent disease D. Estimate the impact of exposure on the incidence of disease C. Evaluate the effectiveness of a substance used to prevent disease Which types of health issues are likely to be addressed in community trials? A. Smoking cessation B. HIV/AIDS C. Healthy eating D. All of the above topics D. All of the above topics The purpose of double-blinding in clinical trials is to: A. Reduce error that results from the way in which the outcome is assessed B. Reduce error that results from subjects' knowledge of their assignment to study conditions C. Reduce error that results from non-random assignment to study conditions D. A and B only E. None of the above D. A and B only The purpose of randomization is to: A. Reduce error that results from the way in which the outcome is assessed B. Reduce error that results from subjects' participation in the trial C. Reduce error that results from assignment to study conditions D. A and C only C. Reduce error that results from assignment to study conditions Controlled clinical trials enable researchers to: A. Derive knowledge about the origins of a disease B. Exercise control over who will receive an exposure C. More accurately identify cause and effect associations D. All of the above D. All of the above Define Arm: A. A study plan on which all clinical trials are based B. Any of the treatment groups in a randomized trial C. The process of learning the key facts about a clinical trial before deciding whether or not to participate