The nurse is conducting a study on how regular physical activity affects the risk for developing lung cancer among smokers
One group leads a sedentary lifestyle whereas the other has agreed to undergo regular supervised exercise in the gym of a local hospital. During the study, the sole treadmill in the gym broke down and was unable to be used for the last half of the study. Several study participants who preferred the treadmill to other machines did not exercise as long or as intensely as they might otherwise have. Which threat to the external validity of the study does this represent?
A) Interaction of history and intervention
B) Interaction of selection and intervention
C) Experimenter/participant effect
D) Novelty
Ans: A
Feedback:
Interaction of history and intervention occurs when the circumstances of the study influence the results of the study, decreasing the generalizability of the findings. Such is the case with the broken treadmill that potentially decreased the participant's overall exercise volume. Interaction of selection and intervention occurs when subjects willing to participate in the study are not representative of the target population, thus limiting the generalizability of the results. Experimenter/participant effect occurs when the researcher has preconceived expectations of the intervention, resulting in bias and affecting the generalizability of the findings. Novelty occurs when a new intervention affects the outcome of the study because of either enthusiasm or skepticism by the researchers or the participants.
You might also like to view...
The nurse is caring for an older adult who has dementia. The patient has just returned from recovery after a percutaneous endoscopic gastrostomy (PEG) tube placement. Which interven-tion(s) should the nurse implement? (Select all that apply.)
a. Place IV tubing behind the patient. b. Hang the IV bag behind the patient's field of vision. c. Cover the PEG tube with an abdominal binder. d. Use wrist restraints.
A patient who suffered a spinal cord injury is experiencing an exaggerated autonomic response. What aspect of the patient's current health status is most likely to have precipitated this event?
A) The patient received a blood transfusion. B) The patient's analgesia regimen was recent changed. C) The patient was not repositioned during the night shift. D) The patient's urinary catheter became occluded.
The nurse palpates the posterior chest while the patient says "99" and notes absent fremitus. Which action should the nurse take next?
a. Palpate the anterior chest and observe for barrel chest. b. Encourage the patient to turn, cough, and deep breathe. c. Review the chest x-ray report for evidence of pneumonia. d. Auscultate anterior and posterior breath sounds bilaterally.
In addition to those barriers faced by many residents in rural areas, what additional barrier to health care is a Hispanic migrant farmworker likely to encounter?
a. Absence of culturally competent care b. Availability of specialists c. Distance of health care facilities from the place of residence d. High cost of health care