Observational Study Designs
A clinical pediatric nurse has noticed a rise in childhood asthma diagnoses among the Hispanic population served by the local clinic. The nurse is concerned about this increase in asthma 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 asthma 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 asthma) can be evaluated using an observational study design. A relevant case-control study would match a group of controls (no asthma) with the case group (asthma diagnosis). Both groups would then be assessed on certain historical exposures like (a) family history; (b) early childhood respiratory infections; (c) secondhand smoke exposure; (d) urban residence (ozone); and (e) obesity. Measures might include interviews, surveys, and medical records. If results show the case group has a higher rate of exposure to a given risk factor, the researcher may conclude that exposure results in greater odds of asthma.
In any epidemiological study, the design and methodology used should be appropriate for that study and for the research question. It is important for researchers to understand the strengths and limitations of each of the study designs and methods. This gives them a better chance of correctly interpreting results and synthesizing them for use in developing and implementing evidence-based population health programs. For this Discussion, you will explore the strengths and limitations of various types of observational study designs and critique their appropriateness for specific studies.
This type of suspected association between a risk factor (exposure) and a particular outcome (childhood asthma) can be evaluated using an observational study design. A relevant case-control study would match a group of controls (no asthma) with the case group (asthma diagnosis). Both groups would then be assessed on certain historical exposures like (a) family history; (b) early childhood respiratory infections; (c) secondhand smoke exposure; (d) urban residence (ozone); and (e) obesity. Measures might include interviews, surveys, and medical records. If results show the case group has a higher rate of exposure to a given risk factor, the researcher may conclude that exposure results in greater odds of asthma.
In any epidemiological study, the design and methodology used should be appropriate for that study and for the research question. It is important for researchers to understand the strengths and limitations of each of the study designs and methods. This gives them a better chance of correctly interpreting results and synthesizing them for use in developing and implementing evidence-based population health programs. For this Discussion, you will explore the strengths and limitations of various types of observational study designs and critique their appropriateness for specific studies.
Resources
Be sure to review the Learning Resources before completing this activity.
Click the weekly resources link to access the resources.
Learning Resources
·
· Friis, R. H., & Sellers, T. A. (2021).
Epidemiology for public health practice (6th ed.). Jones & Bartlett.
. Chapter 6, “Study Designs: Ecologic, Cross-Sectional, Case Control”
. Chapter 7, “Study Designs: Cohort Studies”
· Bahr, R., Clarsen, B., Derman, W., Dvorak, J., Emery, C. A., Finch, C. F., Hägglund, M., Junge, A., Kemp, S., Khan, K. M., Marshall, S. W., Meeuwisse, W., Mountjoy, M., Orchard, J. W., Pluim, B., Quarrie, K. L., Reider, B., Schwellnus, M., Soligard, T., Stokes, K. A., … Chamari, K. (2020).
International Olympic Committee consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020 (including STROBE Extension for Sport Injury and Illness Surveillance (STROBE-SIIS))Links to an external site..
British Journal of Sports Medicine,
54(7), 372–389.
· Community Preventative Services Task Force. (n.d.).
The community guideLinks to an external site.
.
· Framingham Heart Study. (n.d.).
Epidemiological background and design: The Framingham heart studyLinks to an external site.
.
· STROBE. (2021).
HomeLinks to an external site..
The STROBE Checklist is considered the gold-standard in assessing the quality of observational research studies.
· U.S. Department of Health and Human Services. (n.d.).
Healthy People 2030Links to an external site.
.
Articles for this week’s Discussion:
Note: By Day 1, your Instructor will assign you to a small group. Your group will be assigned
two of the following articles to analyze.
· Batty, G. D., & Hamer, M. (2020).
Vascular risk factors, Framingham risk score, and COVID-19: Community-based cohort studyLinks to an external site.. Cardiovascular Research,
116(10), 16641665.
· Hillyer, G. C., Nazareth, M., Lima, S., Schmitt, K. M., Reyes, A., Fleck, E., Schwartz, G. K., & Terry, M. B. (2021).
E-cigarette use among young adult patients: The opportunity to intervene on risky lifestyle behaviors to reduce cancer riskLinks to an external site..
Journal of Community Health. Advance online publication.
· Kebede, E., Kekulawala, M. (2021).
Risk factors for stillbirth and early neonatal death: A case-control study in tertiary hospitals in Addis Ababa, EthiopiaLinks to an external site..
BMC Pregnancy and Childbirth,
21(1), Article 641.
· Najafpour, Z., Godarzi, Z., Arab, M., & Yaseri, M. (2019).
Risk factors for falls in hospital in-patients: A prospective nested case control studyLinks to an external site..
International Journal of Health Policy and Management,
(5), 300–306.
· Whittle, R. S., Diaz-Artiles, A. (2020).
An ecological study of socioeconomic predictors in detection of COVID-19 cases across neighborhoods in New York CityLinks to an external site..
BMC Medicine, 18(1),Article 271.
· Spector, A. L., Quinn, K. G., McAuliffe, T. L., DiFranceisco, W., Bendixen, A., Dickson-Gomez, J. (2020).
Health-related quality of life and related factors among chronically homeless adults living in different permanent supportive housing models: A cross-sectional studyLinks to an external site..
Quality of Life Research: An International Journal of Quality-of-Life Aspects of Treatment, Care and Rehabilitation,
29(8), 20512061.
· Palència, L., Ferrando J., Marí-Dell’Olmo, M., Gotsens, M., Morrison, J., Dzurova, D., Lustigova, M., Costa, C., Rodríguez-Sanz, M., Bosakova, L, Santana, P., & Borrell, C. (2020).
Socio-economic inequalities on cancer mortality in nine European areas: The effect of the last economic recessionLinks to an external site..
Cancer Epidemiology,
69, Article 101827.
· Nguyen, L. H., Örtqvist, A. K., Cao, Y., Simon, T. G., Roelstraete, B., Song, M., Joshi, A. D., Staller, K., Chan, A. T., Khalili, H., Olén, O., & Ludvigsson, J. F. (2020).
Antibiotic use and the development of inflammatory bowel disease: A national case-control study in SwedenLinks to an external site..
The Lancet. Gastroenterology & Hepatology,
(11), 986–995.
· The Challenges of Conducting Trials
Time Estimate: 2 minutes
· Let’s Learn Public Health. (2017, May 5).
Epidemiological studies—made easy! [Video].Links to an external site.
YouTube.
Note: The approximate length of this media piece is 10 minutes.
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 when it is appropriate to use each of the observational study designs.
· Consider how using observational study designs can lead to improvements in population health.
· By Day 1 of this week, you should have received a communication from your Instructor assigning you to a small group to review two specific articles. Review the two articles your group was assigned, with a critical eye toward the researchers’ use of study design and their selected methods. Although several students will be assigned the same articles, this is NOT a group project; please submit your Discussion posts individually. You will then have the opportunity to discuss and share your thoughts with your colleagues.
By Day 3 of Week 3
In your assigned group area:
Post a brief description of the two studies you were assigned, with a particular focus on the study design and methods. Then:
· Describe at least one strength and one limitation of each study’s design.
· Identify the population, data sources, and epidemiologic measures of association that the authors used.
· Finally, share your insights about the appropriateness of the design for the study. Do you agree with the researchers’ choice of design?
· Do you agree with the researchers’ conclusions? Justify your reasoning.
By Day 5 of Week 3
Post at least
two substantive responses to peers
in a different group who analyzed at least one different article in their initial post. Include information from the Learning Resources in your responses as appropriate. You may expand on each peer’s posting with additional insight and resources about study designs, ask a question to further the discussion, or offer polite disagreement or critique supported with evidence. You may also make a suggestion or comment that guides or facilitates the discussion. At least one of your response posts should address the applicability of observational studies for improving population health status.
By Day 7 of Week 3
Respond to any questions you may have been asked by your peers in
your assigned group area. Note what you have learned and/or any insights you have gained as a result of reading the
RESPOND TO THIS DISCUSSION POST
Observational Study Designs: Case-Control Studies in Maternal and Patient Safety Research
Observational study designs play a crucial role in epidemiology by allowing researchers to assess associations between exposures and outcomes in real-world settings. The two studies assigned for this discussion utilized a
case-control design to evaluate risk factors for perinatal mortality and hospital falls. Below is a breakdown of their study designs, strengths, limitations, and overall appropriateness.
Study One: Risk Factors for Stillbirth and Early Neonatal Death
Kebede & Kekulawala (2021) conducted a
case-control study to investigate risk factors for stillbirth and early neonatal death in two tertiary hospitals in Addis Ababa, Ethiopia. Researchers collected data from
patient medical
records, focusing on delivery outcomes, treatment history, and socioeconomic factors. The
control group consisted of women delivering at the same hospitals during the study period, selected through systematic random sampling.
·
Strength: The study effectively controlled for confounding by selecting a
control group from the same hospital setting and utilizing
experienced midwives for data collection, ensuring high data accuracy and consistency.
·
Limitation: A key limitation is that the study only included cases from
university hospitals, which may provide more advanced care than non-academic centers. This could limit the
generalizability of the findings to rural or lower-resource settings. Additionally, excluding infants who died post-discharge (but within seven days) may
underestimate perinatal mortality rates, as defined by the
World Health Organization (WHO, 2025).
· Population & Data Sources: The study examined women delivering at university hospitals, with data extracted from hospital records.
· Epidemiologic Measures: The authors used odds ratios (ORs) to measure the association between various risk factors and perinatal mortality.
· Appropriateness of Design: The case-control approach is well-suited for rare outcomes like stillbirths and neonatal deaths because it allows efficient data collection without requiring large, lengthy cohort studies. Given the study’s resource constraints, I agree with the researchers’ choice of design and data collection methods.
Study Two: Risk Factors for Falls in Hospitalized Patients
Najafpour et al. (2019) also utilized a case-control design to assess risk factors for hospital falls in an 800-bed university hospital over a nine-month period.
Data were gathered from
medical records, patient interviews, and direct observations. The study included
185 case patients (those who fell) and 1,141 control patients, all of whom were considered high-risk for falls.
·
Strength: A major strength of this study is the use of a
multilevel analysis, which provided a
comprehensive evaluation of fall-related risk factors by integrating
patient history, environmental conditions, and institutional protocols. Additionally, selecting control patients from the
same hospital setting and similar demographics (age and performance status) strengthens the internal validity.
·
Limitation: A key limitation is the study’s
single-hospital setting, which restricts the
generalizability of findings to other healthcare facilities with different patient populations or fall prevention protocols.
· Population & Data Sources: Hospitalized patients in a university hospital, with data from medical records, interviews, and observations.
· Epidemiologic Measures: The study used odds ratios (ORs) to assess the relationship between various patient characteristics and fall risk.
· Appropriateness of Design: The case-control design is appropriate because falls are relatively uncommon among hospitalized patients, making a cohort study impractical. The study’s methodology effectively captures both patient-related and hospital-related risk factors. I agree with the researchers’ conclusions, particularly their emphasis on post-fall root-cause analysis as a strategy to reduce future incidents and improve patient safety.
Final Insights on Observational Study Designs
Both studies demonstrate how
case-control designs allow researchers to
identify risk factors for critical health outcomes in a cost-effective and efficient manner. While
cohort studies might provide stronger causal inference, they are often not feasible due to
time and resource constraints. These case-control studies contribute valuable
population health insights, guiding targeted interventions—such as
improving maternal care protocols and
enhancing fall prevention strategies—that can ultimately reduce adverse health outcomes.
Kebede, E., & Kekulawala, M. (2021). Risk factors for stillbirth and early neonatal death: A case-control study in tertiary hospitals in Addis Ababa, Ethiopia. BMC Pregnancy and Childbirth, 21(1), Article 641.
Links to an external site.
Najafpour, Z., Godarzi, Z., Arab, M., & Yaseri, M. (2019). Risk factors for falls in hospital in-patients: A prospective nested case-control study. International
Journal of Health Policy and Management, 8(5), 300–306.
Links to an external site.
comments your peers made.
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