Measures Used in Epidemiology
One important application of epidemiology is to identify factors that could increase the likelihood of a certain health problem occurring within a specific population. Epidemiologists use
measures of effect to examine the association or linkage in the relationship between risk factors and emergence of disease or ill health. For instance, they may use measures of effect to better understand the relationships between poverty and lead poisoning in children, smoking and heart disease, or low birth weight and future motor skills. The following are some common measures used in epidemiology:
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Odds ratio: The odds ratio quantifies the association between an independent variable (exposure) and a dependent variable (outcome). It is calculated as the odds that an effect will occur given the presence or exposure to a studied variable, compared to the odds when there is no exposure (e.g., lung cancer and smoking)
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Risk ratio (also called relative risk): Also quantifies the association between an independent variable and a dependent variable. The risk of an effect occurring in one population versus another population (e.g., preeclampsia in women <35 versus >35). Risks greater than one suggest that exposure to a given variable is associated with an increase in the risk of the outcome, and a risk ratio of less than one indicates that the exposure is associated with a decrease in the risk of the outcome.
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Mortality: Measure of deaths in a particular population during a specified time interval. If this is attributed to a specific cause, it is referred to as cause-specific mortality.
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Morbidity: Measure of instances of illness or disability in a population from a given cause (e.g., heart disease) during a specified time interval
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Incidence: The occurrence of new cases of an effect or disease in a population over a defined time period relative to the size of the population at risk (e.g., new cases of COVID-19 in a population over a 7-day period/1000 people)
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Prevalence: The number of all cases of an effect or disease, not just new ones, in a population at a given time relative to the size of the population (e.g., number of people with autism/1000)
What is the significance of these measures of effect for nursing practice? In this Discussion, you will consider this pivotal question.
Resources
Be sure to review the Learning Resources before completing this activity.
Click the weekly resources link to access the resources.
· Curley, A. L. C. (Ed.). (2024).
Population-based nursing: Concepts and competencies for advanced practice (4th ed.). Springer.
· Chapter 4, “Epidemiological Methods and Measurements in Population-Based Nursing Practice: Part I” (pp. 68-105)
· Friis, R. H., & Sellers, T. A. (2021).
Epidemiology for public health practice (6th ed.). Jones & Bartlett.
· Chapter 3, “Measures of Morbidity and Mortality Used in Epidemiology”
· Chapter 9, “Measures of Effect”
To prepare:
· Select item 1, 2, or 3 to use for this Discussion. Consider the definitions, differences, and utility of the two terms listed under your item selection. Your response will need to include both terms in the item selected.
1. Odds ratio and risk ratio
2. Mortality and morbidity
3. Incidence and prevalence
· Consider how these epidemiologic measures strengthen and support nursing practice.
· Assess practice limitations of not using these measures in nursing practice.
· Conduct additional research in the Walden Library and other credible resources, and then locate two examples in the scholarly literature that support your insights.
By Day 3 of Week 5
Post a cohesive scholarly response that addresses the following:
· Explain how your selected measures of effect strengthen and support nursing practice. Provide at least two specific examples from the literature to substantiate your insights.
· Assess limitations of
not using measures of effect in nursing practice.
By Day 6 of Week 5
Respond to
at least two colleagues on
two different days in one or more of the following ways:
· Ask a probing question, substantiated with additional background information, evidence or research.
· Share an insight from having read your colleagues’ postings, synthesizing the information to provide new perspectives.
· Offer and support an alternative perspective using readings from the classroom or from your own research in the Walden Library.
· Validate an idea with your own experience and additional research.
· Make a suggestion based on additional evidence drawn from readings or after synthesizing multiple postings.
· Expand on your colleagues’ postings by providing additional insights or contrasting perspectives based on readings and evidence.
RESPOND TO THIS DISCUSSION POST
In nursing and public health, incidence and prevalence are important epidemiological terms that help nurses understand patterns of disease in populations. Although both terms relate to disease occurrence, they measure different aspects. Incidence refers to the number of new cases of a disease or condition that occur in a specific population during a particular time period. It reflects the risk of developing the disease. On the other hand, prevalence measures the total number of cases, both new and existing, in a population at a
specific point in time or over a period of time. This reflects the overall burden of disease within a population.
Understanding incidence and prevalence strengthens nursing practice by helping nurses plan patient care, disease prevention, and health education. For example, high incidence rates signal the need for stronger preventive measures and early detection strategies. Prevalence data helps nurses understand how widespread a health issue is, allowing them to allocate resources and plan for long-term care. If nurses did not use these measures, they might underestimate the scale of disease or fail to identify emerging health threats. This could result in inadequate patient education, prevention efforts, or clinical interventions.
One example from the literature is a study by Dehkordi et al. (2022), which examined the incidence of pressure ulcers in hospitalized patients. The study’s findings highlighted the need for continuous monitoring and preventive care by nurses to reduce the occurrence of pressure ulcers. Without measuring incidence, nurses would lack the data needed to advocate for better prevention strategies. Another study by Sanyaolu et al. (2020) focused on the prevalence of comorbidities in COVID-19 patients. Knowing the prevalence of certain conditions in patients allowed nurses and healthcare teams to identify high-risk groups and adjust care plans accordingly.
In conclusion, incidence and prevalence are critical measures that allow nurses to anticipate health care needs, implement prevention programs, and deliver patient-centered care. Without these measures, nursing practice would lack the data-driven foundation necessary for effective public health and clinical decision-making.
References
Dehkordi, A. H., Shahinfar, J., & Ganjoo, P. (2022). Incidence and risk factors of
pressure ulcers in hospitalized patients: A systematic review.
International Wound Journal, 19(3), 624–635.
Sanyaolu, A., Okorie, C., Marinkovic, A., et al. (2020). Comorbidity and its impact on patients with COVID-19.
SN Comprehensive Clinical Medicine, 2, 1069–1076.
