NUR 520 Module 1 Short Paper Example

Agent, Host and a Northern County: Applying Epidemiologic Concepts to COPD in Coös County, New Hampshire

[Student Name]

Southern New Hampshire University

NUR 520: Epidemiological and Biostatistical Applications in Healthcare

Module One Short Paper

[Instructor Name]

[Date]

Agent, Host and a Northern County: Applying Epidemiologic Concepts to COPD in Coös County, New Hampshire

At the bedside, chronic obstructive pulmonary disease looks like one patient's breathlessness. Epidemiology asks a different question: why does this disease cluster in some populations more than others, and where along its course could it be interrupted? This paper applies two basic epidemiologic tools, the epidemiologic triangle and the natural history of disease, to COPD among adults in Coös County, the northernmost and most rural county in New Hampshire. It argues that the county's high COPD burden reflects a combination of host risk, especially smoking and age, and an environment that makes both prevention and early care harder, and that each stage of the disease offers a distinct opportunity for nursing action.

The Problem in Numbers

CDC's PLACES project produces model-based estimates of health measures for every U.S. county. In its 2025 release, Coös County's estimated crude prevalence of diagnosed COPD among adults was 9.5% (95% confidence interval 7.7% to 11.4%), the highest of New Hampshire's ten counties, and its estimated current smoking prevalence was 15.2%, also the highest in the state (Centers for Disease Control and Prevention [CDC], 2025). For comparison, a population-weighted average of the ten county estimates gives about 6.2% for COPD and 10.8% for smoking statewide; that average was calculated for this paper from the county figures, not published by CDC. Nationally, age-standardized COPD prevalence among U.S. adults was about 6% throughout 2011 to 2021, and prevalence remained higher among adults aged 65 and older, those living in rural areas and those who have ever smoked (Liu et al., 2023).

The Epidemiologic Triangle

The epidemiologic triangle describes disease as the product of an agent, a susceptible host and an environment that brings them together (Celentano & Szklo, 2019). It was developed for infectious disease but remains useful for chronic conditions when the agent is understood as an exposure.

Agent. For COPD, the dominant agent in the United States is tobacco smoke. Other inhaled exposures, including occupational dusts and fumes and indoor smoke from heating or cooking, can contribute. Coös County's long history of paper milling and wood heating makes occupational and household exposures worth asking about, although county data cannot show how much they contribute.

Host. Host factors include smoking history, age, genetics and early-life lung development. Coös has an older population than most of the state, and the national data show COPD prevalence rising with age and remaining high among current and former smokers (Liu et al., 2023). Higher smoking prevalence among Coös adults means more hosts with sustained exposure.

Environment. The environment includes the physical and social conditions that shape exposure and care. Coös is rural, with long distances to specialty care; PLACES estimates also show higher shares of adults without health insurance and without reliable transportation than the state as a whole (CDC, 2025). These conditions do not cause COPD directly, but they make cessation support, diagnosis and pulmonary rehabilitation harder to reach.

The Natural History of COPD

The natural history of disease describes its course without intervention, from susceptibility through subclinical disease, clinical disease and outcomes such as recovery, disability or death (Celentano & Szklo, 2019). COPD fits the model closely. In the stage of susceptibility, an adult begins smoking or is exposed to dust or smoke at work, with no lung damage yet. In the subclinical stage, airflow limitation develops and may be measurable by spirometry, but the person may notice only a morning cough or reduced stamina and attribute it to age. In the clinical stage, breathlessness, sputum and exacerbations bring the person to care, often in an emergency department. In the stage of disability, the person may depend on oxygen, lose the ability to work and experience repeated hospitalizations.

Levels of Prevention and Nursing Roles

Each stage maps onto a level of prevention. Primary prevention acts in the stage of susceptibility, and in Coös that means tobacco prevention and cessation: nurse-led counseling in primary care, referrals to the state quitline and advocacy for cessation coverage. Secondary prevention acts in the subclinical stage by finding disease early in people with symptoms. The national task force recommends against screening adults who have no respiratory symptoms (US Preventive Services Task Force et al., 2022), so the nursing role here is case finding, asking smokers with cough or breathlessness about symptoms and arranging spirometry. Tertiary prevention acts in the clinical and disability stages through inhaler teaching, action plans, vaccination, pulmonary rehabilitation and transitions of care that reduce exacerbations and readmissions. In a rural county, telehealth and home-based rehabilitation may extend tertiary prevention to people who cannot travel.

Why Population Thinking Matters for the MSN Nurse

A bedside nurse in a Coös County hospital cares for one patient with an exacerbation at a time. An MSN-prepared nurse leading a clinic, a care management program or a hospital's population health work must ask how many more patients are in the stages that come before the emergency department, and which intervention would reach the most of them. The triangle identifies what to target, the natural history identifies when, and the data identify where the burden is greatest. Without that frame, resources tend to flow to the most visible stage, acute care, rather than to the stages where prevention has the greatest effect. The same thinking helps an MSN nurse decide what to measure: a clinic serious about COPD in Coös would track the share of patients who smoke and were offered cessation help, and the share of patients with symptoms who received spirometry, not only admissions.

Conclusion

Coös County carries New Hampshire's highest estimated burden of COPD and smoking. The epidemiologic triangle shows that the burden reflects a common agent, an older and more exposed host population and an environment that makes prevention and care harder to reach. The natural history of COPD shows where nursing can intervene at each stage, from cessation support to rehabilitation. Later modules will examine the data sources behind these estimates and test whether the county's difference from the rest of the state holds up under age adjustment.

References

Celentano, D. D., & Szklo, M. (2019). Gordis epidemiology (6th ed.). Elsevier.

Centers for Disease Control and Prevention. (2025). PLACES: County data (GIS friendly format), 2025 release [Data set]. https://data.cdc.gov/d/i46a-9kgh

Liu, Y., Carlson, S. A., Watson, K. B., Xu, F., & Greenlund, K. J. (2023). Trends in the prevalence of chronic obstructive pulmonary disease among adults aged 18 years and older: United States, 2011-2021. Morbidity and Mortality Weekly Report, 72(46), 1250-1256. https://doi.org/10.15585/mmwr.mm7246a1

US Preventive Services Task Force, Mangione, C. M., Barry, M. J., Nicholson, W. K., Cabana, M., Caughey, A. B., Chelmow, D., Coker, T. R., Davis, E. M., Donahue, K. E., Jaén, C. R., Kubik, M., Li, L., Ogedegbe, G., Pbert, L., Ruiz, J. M., Stevermer, J., Tseng, C.-W., & Wong, J. B. (2022). Screening for chronic obstructive pulmonary disease: US Preventive Services Task Force reaffirmation recommendation statement. JAMA, 327(18), 1806-1811. https://doi.org/10.1001/jama.2022.5692