Suppose a researcher conducted a cross-sectional study on attention deficit hyperactivity disorder (ADHD) and externalizing behaviors (e.g., rule-breaking or defiant behavior) among adolescents in Hillsborough County. During the summer months, the researcher works as a volunteer at a summer education program for adolescents who struggle with their schoolwork. Since the participants of the summer education program are adolescents, the researcher decides to invite the adolescents who attend the summer program for participation in the study.   The researcher is worried that there might be selection bias in the estimate of the effect of ADHD on externalizing behaviors because ADHD and externalizing behaviors are both reasons for participation in the summer program and are therefore also both affect study participation. To assess potential selection bias, the researcher drew the directed acyclic graph (DAG) in Figure 2.   Based on the DAG in Figure 2, will there be selection bias (yes/no)? (2 points) Explain your answer (max. 4 points).

What shape is Treponema pallidum?

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 source of measurement error could affect the measurement of hypertension in case 1? (2 points) Explain why you chose this source of measurement error (2 points).

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 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)

Which of the following diseases would be associated with Borrelia burgdorferi? 

Do you have Google Chrome downloaded?

Which of the following conditions would be associated with Rickettsia rickettsii? 

After administering epinephrine to a client in anaphylactic shock, which action will the nurse perform next?

An oxygen hood is an appropriate oxygen delivery system for an infant who requires: