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What is the most important electrolyte for ventricular repolarization?

What does elevation of the ST segment signify?

What nerve provides sensory innervation to the base of the tongue, the posterior epiglottis, the aryepiglottic folds, and the arytenoids?

Case 1 (Questions 11-13) Suppose a team of researchers conducts a case-control study on the association between hypertension and stroke among adults aged 50 and older in Florida. For this study, the researchers selected Floridian adults aged 50 and older who experienced a stroke as the cases. As controls, the researchers selected Floridian adults aged 50 or older who did not experience a stroke. To assess each participant’s exposure status, the researchers asked the participants to fill out a questionnaire in which the participants were asked to retrospectively report if they have had hypertension in the past.   What strategy could be used to minimize error in the measurement of hypertension in case 1? (max. 4 points)

Suppose a team of researchers was interested in studying whether individuals with generalized anxiety disorder are more likely to abuse substances. The researchers used a cross-sectional design and sampled individuals who were being treated at the psychiatry department of Tampa General Hospital. After enrolment, the researchers used the medical records of the participants to determine both anxiety disorder status and substance abuse status. The researchers found that substance abuse was 0.90 times more prevalent among individuals with an anxiety disorder compared to individuals without anxiety disorder. In other words, individuals with anxiety disorder less often abused substances compared to individuals without anxiety disorder.   The researchers submitted a manuscript with their finding to a peer-reviewed journal. One of the reviewers points out that the estimated prevalence ratio of 0.90 is counterintuitive and that this counterintuitive finding may be explained by selection bias.   Which two (2) conditions need to hold for selection bias to occur in this study on anxiety disorder and substance abuse? (max. 4 points per condition)

Suppose a researcher is interested in investigating the effect of occupational noise exposure on hearing loss. The researcher hypothesizes that the effect of occupational noise exposure on hearing loss will be less strong for individuals who wear hearing protection (e.g., ear plugs) while on the job, compared to individuals who do not wear hearing protection while on the job. The researcher also hypothesizes that individuals who are exposed to high levels of occupational noise are more likely to wear hearing protection than individuals who are not exposed to high levels of occupational noise. Finally, the researcher hypothesizes that the use of hearing protection has a protective effect on hearing loss.   Based on the researcher’s hypotheses, which of the options below best describes the role of hearing protection use in the effect of occupational noise exposure on hearing loss?

Case 2 (Questions 19 and 20) Suppose a team of researchers conducted a prospective cohort study on the effect of physical activity on the 6-month risk of depression. To assess potential effect modification by gender, the researchers estimated the effect of physical activity on depression separately for men and women. In men, the estimated risk difference was -0.11 and the estimated risk ratio was 0.71. In women, the estimated risk difference was -0.07 and the estimated risk ratio was 0.80. Based on these effect estimates the researchers concluded that gender is indeed an effect modifier, so the researchers decided to report the conditional effect estimates in their manuscript.   Please provide an interpretation of the estimated risk ratio of 0.71. Assume that physical activity was the exposure level of interest and physical inactivity was the comparison level. (max. 4 points)

Suppose a team of researchers studied the association between arsenic exposure and skin cancer using a case-control study. The researchers were interested in studying smoking as an effect modifier of the association between arsenic exposure and skin cancer. To determine if smoking is an effect modifier, the researchers compared the observed joint exposure odds ratio to the expected joint exposure odds ratio. The observed joint exposure odds ratio was 2.37 and the expected joint exposure odds ratio was 1.93.    What is the correct conclusion based on the available information presented above?

Suppose a researcher was interested in investigating bone fractures as a potential exposure affecting pneumonia (i.e., lung infection). To study this, the researcher decided to sample individuals who attended the emergency room (ER) of Tampa General Hospital, because bone fractures and pneumonia are both reasons for attending the ER.    What form of selection bias may affect the results from this study?

Case 1 (Questions 11-13) Suppose a team of researchers conducts a case-control study on the association between hypertension and stroke among adults aged 50 and older in Florida. For this study, the researchers selected Floridian adults aged 50 and older who experienced a stroke as the cases. As controls, the researchers selected Floridian adults aged 50 or older who did not experience a stroke. To assess each participant’s exposure status, the researchers asked the participants to fill out a questionnaire in which the participants were asked to retrospectively report if they have had hypertension in the past. When is the measurement error in hypertension in case 1 differential? (max. 4 points)