AIPGMEE 2015

1. 1. Epidemiology is broadly defined as the study of factors that influence the health of populations. The application of epidemiologic findings to decisions in the care of individual patients is:
   A.    Generally inappropriate
   B.     Known as clinical epidemiology
   C.     Limited to chronic disease epidemiology
   D.    Limited to infectious disease epidemiology
   E.     Limited to biologic mechanisms rather than social and environmental considerations
   Answer
   B. Clinical practice is devoted to the care of individual patients. Outcomes in individual patients in response to clinical interventions cannot be known, however, until after the interventions have been tried. The basis for choosing therapy (or for choosing diagnostic tests) is prior experience in similar patients, rather than knowledge of what would work best for the individual. The use of clinically applied statistics, probability, and population-based data to inform medical decisions is known as clinical epidemiology. Clinical epidemiology pertains to all clinical care. Its findings and applications are not limited to infectious diseases (D) or chronic diseases (C), or to biologic mechanisms (E). Social and environmental considerations are very relevant to clinical decision making (E). Far from being inappropriate (A), the application of epidemiologic principles to patient care is fundamental to evidence-based practice and is supportive of robust clinical decisions.
   2.      Tim has a severe heart attack at age 58. The near-death experience so scares Tim that he quits smoking. Tim’s wife is also scared into quitting smoking even though she feels fine. Tim’s son resolves never to start smoking, seeing what cigarettes have done to his dad. The act of not smoking for Tim, Tim’s wife, and Tim’s son represents:
   A.    Host, vector, and agent effects, respectively
   B.     Herd immunity
   C.     Tertiary prevention for Tim’s son
   D.    Tertiary prevention, primary prevention, and secondary prevention, respectively
   E.     Tertiary prevention, secondary prevention, and primary prevention, respectively
   Answer
   E. Prevention means intervening to interrupt the natural history of disease. Primary prevention represents the earliest possible interventions to foil disease before it even begins (e.g., Tim’s son never starting to smoke). Secondary prevention is thwarting the progression of established disease that has not yet declared itself with symptoms or outward signs (e.g., Tim’s asymptomatic wife quitting smoking). Tertiary prevention is slowing, arresting, or even reversing obvious or symptomatic disease to prevent worsening symptoms and further deterioration (e.g., Tim quitting smoking after his heart attack). Answer choices (C) and (D) get distinctions between these stages of disease prevention wrong. Herd immunity (B) is the prevention of disease transmission to susceptible individuals through acquired immunity in others. Herd immunity does not apply to the scenario involving Tim and his family. Likewise, definitions for host (i.e., susceptible individual), vector (i.e., unaffected carrier), and agent (i.e., medium of harm) (A) do not apply to the characterizations of Tim and his family.