Assignment task: 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. Need Assignment Help?
Resources:
Required Readings:
- Friis, R. H., & Sellers, T. A. (2021). Epidemiology for public health practice (6th ed.). Jones & Bartlett.
o Chapter 6, "Study Designs: Ecologic, Cross-Sectional, Case Control"
o 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)
- Community Preventative Services Task Force. (n.d.). The community guide
- Framingham Heart Study. (n.d.). Epidemiological background and design: The Framingham heart study.
- STROBE. (2021). Home
- 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 2030
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 study. 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 risk. 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, Ethiopia. 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 study. 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 City. 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 study. 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 recession. 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 Sweden. The Lancet. Gastroenterology &Hepatology, (11), 986-995.
Required Media:
- The Challenges of Conducting Trials
- Let's Learn Public Health. (2017, May 5). Epidemiological studies-made easy! [Video]. 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.
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.
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.
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
Susan
Discussion Initial Post-Susan Horne
Post a brief description of the two studies you were assigned, with a particular focus on the study design and methods. Then:
Study 1: Risk factors for stillbirth and early neonatal death: a case-control study in tertiary hospitals in Addis Ababa, Ethiopia. Unmatched case-control study. For this study, the authors studied two groups of women who gave birth between October 2016 and May 2017. The study was conducted at two hospitals. The two groups compared were women who had live births vs women who had either antepartum, intrapartum, or early neonatal death-7 days). Total participants: 1077. Controlled group: 711. Case study group: 366.
Study 2: Risk factors for falls in hospital in-patients: a prospective nested case control study. Prospective nested case-control study. For this study, the authors studied two groups of hospitalized patients. All patients in the study were determined to be at high risk of falling. The study ran from June 2016 to March 2017. A total of 1141 patients were in the study. The criteria for the study required patients to have a Morse Fall Scale score of 45 or higher. Out of this group, a total of 185 patients experienced a fall.
Each case study was conducted using a case-control style. According to Tenny et al. (2023), a case-control study compares two groups of individuals-one group with condition being studied and one group without. The authors go on to discuss that a case-control study is typically considered an observational study, meaning that there is no outside intervention from the researchers. Study one looks at women who have live births vs women who have live births vs women who have antepartum, intrapartum, or early neonatal death. The authors do not alter any of the study but look at factors that could affect the results. In study 2, the authors compare patients that are at risk of falling to those that fall. Each study has a set amount of time that the information was collected. Both case-controlled studies are broken down further into an unmatched one and a prospective nested one. The Office for Health Improvement and Disparities (2021) defines an unmatched case-control study as one where the individuals are chosen at random. The other case-control study used was the nested case-control study. Ernest (1994) reports that a group of controls with a potential compared to ones that do happen during the time frame of the study.
- Describe at least one strength and one limitation of each study's design.
Strength: Ernest (1994) discusses an important strength in both nested and unmatched case-controlled studies as the studies are typically in the same population.
Limitation: In the reports by the Office for Health Improvement and Disparities (2021), a limitation for these types of studies is the lack of ability to determine causation.
- Identify the population, data sources, and epidemiologic measures of association that the authors used.
Study 1: Population-women giving birth at either Tikur Anbessa Hospital or Gandhi Memorial Hospital from October 2016 to May 2017. Data Sources-
Data capture sheet with (1) demographic information, prior obstetric history, antenatal care, complications of current pregnancy and labor (2) stillbirth and early neonatal cases (3) multiple pregnancies and/or deliveries. Epidemiologic measures-Odds ratio: obstetric factors is the highest.
Study 2: Population-Total of 1326 patients with a score of 45 or more on the Morse Fall Scale from June 2016-March 2017. Ending results 185 patients who had a fall (case) and 1141 patients who did not fall (controlled). Data Sources-Data collection tool with variables (demographics, medications taken within 24 hours, fall risk level, history of fall, health status variables-all patients) (place/date/time of fall, activity level, location, and injury-patients that fall). Epidemiologic measures-Odds ratio: increase in falls with drugs (sedative, anticonvulsants, anti-diabetic agents, benzodiazepines, ACE inhibitors, anti-infective agents, antihistamine, and chemotherapy).
- Finally, share your insights about the appropriateness of the design for the study. Do you agree with the researchers' choice of design?
I do think both studies used appropriate designs. First, study one used the unmatched case-control study. This allowed researchers to look at a group of patients and compare factors that could have a result on the outcome to determine if there is a risk. Second, study 2 used prospective nested case-control study. This uses patients that could have something happen but doesn't necessarily mean it will happen.
- Do you agree with the researchers' conclusions? Justify your reasoning.
Study 1: Yes, I do feel like the researchers' conclusion if appropriate. The authors can compare data from their study with others and have found similar results. They go on to report ways to use what was found in the study to improve the outcome for patients and prevention of loss.
Study 2: Study 2 does discuss factors that increase a patients risk of fall but includes all of the variables as reasons why patients are at risk of falling.
References:
Ernster, V. L. (1994). Nested Case-Control Studies. Preventive Medicine, 587-590.
Kebede, E., &Kekulawala, M. (2021). Risk factors for stillbirth and earlyneonatal death: a case-control study in tetriary hospitals in Addis Ababa, Ethiopia. BMC Pregnancy and Childbirth, 21(64). doi:10.1186/s12884-021-04025-8
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. doi:10.15171/ijhpm.2019.11
Office for Health Improvement and Disparities. (2021, May 19). Case-control study: comparative studies. Retrieved from Gov.UK
Tenny, S., Kerndt, C. C., & Hoffman, M. R. (2023). Case Control Studies.
Retrieved from National Library of Medicine