Question 1 is based on the following scenario: Arising from…

Question Answered step-by-step Question 1 is based on the following scenario: Arising from… Question 1 is based on the following scenario:Arising from concerns based on animal studies demonstrating carcinogenicity, the public health department in the Land of Oz investigated the association between exposure to environmental contaminant A and liver cancer. Q1a.What sort of study design would be best suited for this investigation? Cross-sectional surveyCase-control studyProspective cohortRetrospective cohortNatural experimentAnswer: Q1b.They found a RR of 2.3 (95% CI 1.3, 3.5) for the association between exposure to contaminant A and liver cancer.  Referring to this study and its findings, which of these statements is not true? This association could be explained by confoundingThis association could be explained by residual confoundingThis association is likely to be due to chanceThis association could be explained by biasThis association could represent a causal relationshipAnswer: Based on preliminary laboratory evidence of mutagenicity, exposure to contaminant B was also assessed in the investigation of the association between contaminant A and liver cancer, and incorporated into a subsequent analysis.  In analyses stratified by exposure to contaminant B, they found the following results:Among those exposed to contaminant B: contaminant A—liver cancer RR = 1.5 (95% CI 1.1, 1.9)Among those not exposed to contaminant B: contaminant A—liver cancer RR = 1.5 (95% CI 1.3, 1.7) Q1c.How can these results best be explained?The relationship between contaminant A and liver cancer is confounded by contaminant BContaminant A confounds the relationship between contaminant B and liver cancerContaminant B is an effect modifier of the relationship between contaminant A and liver cancerContaminant A is an effect modifier of the relationship between contaminant B and liver cancerCannot make any sound conclusionsAnswer:       Q1d.Based on this study and all of the above-described findings, which of these statements is true? Contaminant A is associated with liver cancerContaminant B is associated with liver cancerNeither contaminant A nor B is associated with liver cancerBoth contaminants A and B are associated with liver cancerNone of the above Answer: Q2. Industrial chemical X has been shown to be associated with adult-onset asthma in exposed workers in a systematic review and meta-analysis of several well-designed and well-conducted prospective cohort studies (good protection against biases in participant selection and collection of data, good control for known confounders, and >80% retention of study participants over the duration of the study).  The summary RR excludes 1.  Choose three of the Hill criteria for causal inference and explain how each could be considered in relation to judging whether this association could be causal. Be sure to name each of the three chosen criteria, and answer using complete sentences Answer:  Q3.Which of the following statements is true?Exposure does not have to precede outcome in a causal relationshipA weak association (e.g., OR = 1.2) cannot be causal A strong association (e.g., OR = 12.0) must be causal A weak association could be causal, but it is harder to eliminate bias and confounding as explanations compared to a strong association None of the aboveAnswer: Q4a.In a randomised controlled trial (RCT) or a prospective cohort study, which of the outcomes below would be least susceptible to observer bias in the circumstance that observer blinding was not feasible?  The observer in this context is the epidemiologist or clinician who assesses the outcomeSymptom reportsA measure of moodA measure of wellbeingA physiological parameter (e.g., through a blood test)None of the above Answer: Q4b. Explain your answer to Q4a using complete sentences  Answer: Q5a.In a clinical randomised controlled trial (RCT) of a new treatment for bipolar disorder, which of the following would be the most appropriate control/comparison group? Assume that there are pharmacological (somewhat effective), psychotherapeutic (somewhat effective), and combined treatments (most effective) available? Standard psychotherapeutic treatmentA historical, somewhat effective treatment Standard pharmacological treatment No treatment at allCurrent best practice pharmacological and psychotherapeutic treatmentAnswer: Q5b. Explain your answer to Q5a using complete sentences. Answer:    Q6a.Assume that there is more than one sufficient cause for a given disease.  In theory, which of the following types of cause would you aim to eliminate for the greatest preventive benefit (to prevent the greatest amount of the disease)? A necessary causeA sufficient causeA component causeA probable causeNo cause at all Answer:      Q6b. Explain your answer to Q6a using complete sentences  Answer:  Science Biology BMS 3052 Share QuestionEmailCopy link Comments (0)