Observational Study Designs
A clinical pediatric nurse has noticed a rise in childhood cancer diagnoses among the Hispanic population served by the local clinic. The nurse is concerned about this increase in cancer incidence in the patient population and turns to the literature to explore current research on this topic. The nurse finds through the reading that there appears to be an association between parental smoking and childhood cancer and wonders if this could be the cause of the rise in cases.
This type of suspected association between a risk factor (exposure) and a particular outcome (childhood cancer) can be evaluated using an observational study design. This week, you were introduced to observational study designs used in epidemiology. For this Discussion, you will identify an epidemiologic association of interest (e.g., smoking and lung cancer, obesity and heart disease, hormone replacement/modification therapy and breast cancer) and determine an appropriate observational study design for exploring that association.
To prepare:
- Review the different types of observational study designs presented in the Learning Resources: ecologic, cross-sectional, case-control, and cohort.
- Carefully examine the characteristics, strengths, and limitations of each design.
- Consider an association between a risk factor and a particular health outcome that is of interest to you. Then, select the observational study design you think would be the most appropriate for exploring this association.
- Consider how using observational study designs can lead to improvements in population health.
By tomorrow 03/14/2018 12 noon, write a minimum of 550 words in APA format with at least 3 scholarly references from the list of required readings below. Include the level one headings as numbered below:
Post a cohesive response that addresses the following:
1) Identify the association between the risk factor and health outcome you selected and suggest which observational study design you feel is most appropriate for examining that association.
2) Support your selection of the observational design, noting its strengths and limitations for addressing the health problem.
3) What might you be able to learn by using your selected study design that might lead to improvements in population health? Support your response with evidence from the literature.
Required Readings
Friis, R. H., & Sellers, T. A. (2014). Epidemiology for public health practice (5th ed.). Sudbury, MA: Jones & Bartlett.
Chapter 6, “Study Designs: Ecologic, Cross-Sectional, Case Control”
Chapter 7, “Study Designs: Cohort Studies”
Chapter 6 presents an overview of analytic study designs used in epidemiology, differentiating between experimental studies (which will be addressed next week) and observational studies (the focus of this week). In the chapter, the authors address three varieties of observational studies—ecological, cross-sectional, and case control. Chapter 7 addresses cohort studies, another form of observational design.
Doll, R., & Hill, A. B. (1999). Smoking and carcinoma of the lung. Bulletin of the World Health Organization, 77(1), 84–93.
This landmark case-control study established the relationship between smoking and lung cancer.
Framingham Heart Study. (1998). Epidemiological background and design: The Framingham study. Retrieved from https://biolincc.nhlbi.nih.gov/static/studies/framcohort/Epidemiological_Background_and_Design.pdf
The Framingham Heart Study is one of the first and largest cohort studies that measured the distribution of suspected risk factors in a large population and then tracked the development of heart disease in that cohort.
Papathanasiou, A. A., & Zintzaras, E. (2010). Assessing the quality of reporting of observational studies in cancer. Annals of Epidemiology, 20(1), 67–73.
In this article, the authors assess the quality of reporting of observational cancer studies, noting opportunities for improvement.
Von Elm, E., Altman, D. G., Egger, M., Pocock, S. J., Gøtzsche, P. C., & Vandenbroucke, J. P. (2007). Strengthening the reporting of observational studies in epidemiology (STROBE) statement: Guidelines for reporting observational studies. Annals of Internal Medicine, 147(8), 573–577.
A consortium of scientists and medical researchers created a checklist of 22 recommended items that should be included in reports about three common observational study designs: case-control, cohort, and cross-sectional studies. This collaborative effort is an important step toward the goal of improving the quality, credibility, and generalizability of analytical research.
Healthy People 2020. (2011). Topics & objectives index. Retrieved from http://healthypeople.gov/2020/topicsobjectives2020/default.aspx
Healthy People 2020 focuses on improving population health locally and nationally. Review the topics and objectives of Healthy People 2020 as you prepare for Assignment 2.
Required Media
Laureate Education, Inc. (Executive Producer). (2012). Epidemiology and population health: Observational studies [Video file]. Baltimore, MD: Author.
Note: The approximate length of this media piece is 9 minutes.
In this week’s program, the presenters discuss observational studies as a means of establishing an association between an exposure or risk factor and a disease outcome. Two types of observational designs are featured: cohort and case control studies.
Optional Resources
The following ERIC notebook guides present information in a reader-friendly study guide format.
Ibrahim, M., Alexander, L., Shy, C., & Farr, S. (1999). Cohort studies. ERIC Notebook, 3, 1–4. Retrieved from http://cphp.sph.unc.edu/trainingpackages/ERIC/eric_notebook_3.pdf
Ibrahim, M., Alexander, L., Shy, C., & Farr, S. (1999). Incidence measures in cohort studies. ERIC Notebook, 4, 1–4. Retrieved from http://cphp.sph.unc.edu/trainingpackages/ERIC/eric_notebook_4.pdf
Ibrahim, M., Alexander, L., Shy, C., & Farr, S. (1999). Case-control studies. ERIC Notebook, 5, 1–4. Retrieved from http://cphp.sph.unc.edu/trainingpackages/ERIC/eric_notebook_5.pdf
Ibrahim, M., Alexander, L., Shy, C., & Farr, S. (1999). Cross-sectional studies. ERIC Notebook, 7, 1–4. Retrieved from http://cphp.sph.unc.edu/trainingpackages/ERIC/eric_notebook_7.pdf
Ibrahim, M., Alexander, L., Shy, C., & Farr, S. (2000). Ecologic studies. ERIC Notebook, 12, 1–4. Retrieved from http://cphp.sph.unc.edu/trainingpackages/ERIC/eric_notebook_12.pdf
