A principal comments to the school nurse that it seems there are a lot more problems with asthma among the students than there were before the school was remodeled a couple of years ago. The nurse investigates the principal’s observation by reviewing all the school records to determine visits to the health office because of asthma by week and month for the past 5 years. Which of the following best describes the type of study the nurse is conducting?

Correct Answer: B

Rationale: The correct answer is B: Ecological study. The nurse is analyzing data at a group level (school) rather than individual level. This type of study evaluates associations between exposure (school remodeling) and outcome (asthma rates) in a population. It does not involve following individuals over time like a cohort study (C). Descriptive epidemiological studies (A) focus on describing the distribution of health outcomes in a population, but do not investigate associations. Choice D does not make sense in this context.

Correct Answer: C

Rationale: The correct answer is C because epidemiology focuses on investigating patterns and causes of diseases in populations. Recommending a restaurant closure due to a norovirus outbreak is a key epidemiological activity as it involves identifying the source of an illness and implementing measures to prevent further spread. A: Prescribing antibiotics is more related to individual treatment rather than population-level disease investigation. B: Teaching a community class on diabetes is more about health education rather than disease surveillance and control. D: Encouraging families to eat dinner together is a community health promotion activity, not directly related to epidemiological investigations.

Correct Answer: A

Rationale: Sure! The hallmark feature of an analytic study in epidemiology is the use of an appropriate comparison group (Choice A). This is essential for drawing valid conclusions about the relationship between an exposure and an outcome. By comparing individuals with the exposure to those without, researchers can assess the association between the exposure and the outcome. Choice B, randomization in recruiting study participants, is more related to experimental studies rather than analytic epidemiological studies. Choice C, confirmation of diagnosis via lab testing, is important for accurate data collection but not unique to analytic studies. Choice D, testing a hypothesis, is a common step in research but does not specifically define an analytic study in epidemiology.

Correct Answer: C

Rationale: The correct answer is C: Prevalence rate. Prevalence rate is used to measure the proportion of a population that has a specific condition at a particular point in time, making it suitable for studying the population that had pneumonia during the winter months. Attack rate (A) is used to measure the proportion of a specific population that develops a new case of a disease within a defined period, typically during an outbreak. Incidence rate (B) measures the rate at which new cases develop in a population over a specific period, which is different from prevalence rate as it focuses on new cases rather than existing cases. Risk ratio (D) compares the risk of developing a certain condition between two different groups, which is not suitable for studying the proportion of the population with pneumonia during the winter months.

Correct Answer: B

Rationale: Certainly! The correct answer is B: Environment. In the epidemiological triad, which aims to explain the spread of diseases, environment plays a crucial role as a component. The environment encompasses all external factors that can influence the host and the agent. It includes physical, biological, and social factors that can impact the transmission and progression of a disease. Susceptibility (A) refers to the host's vulnerability, portal of exit (C) is the route through which an infectious agent leaves the host, and pathogenicity (D) relates to the ability of an agent to cause disease but are not components of the epidemiological triad.