We are making part of the first module of the course available for free so that you can gauge whether the content level is right for you. The quiz and discussion forum is not available

   

Choosing a Study Design

Welcome to the first module in Fundamentals of Global Health Research: Planning, Implementation, and Dissemination. This module will give you some foundational information that will be referred to in other lectures throughout the course. First, we’ll cover some basic epidemiology and biostatistics terms (such as incidence rate and prevalence, exposure and outcome). Then we’ll cover different types of studies commonly used in research projects.

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Learning Objectives

After completing this module, you will be able to:

  • Define basic epidemiological and statistical terms.
  • List the different kinds of study designs and their advantages and disadvantages.
  • Identify which type of study design would work best for different kinds of research questions.
  • Define what qualitative research is.
  • Explain how qualitative research differs from quantitative research.
  • List the different types of mixed-method designs.
  • Explain what positionality and reflexivity are in relation to qualitative research.

Video: Basic Epidemiology & Statistical Terms (18 minutes)

This video lecture by Dr. Alison Drake will define basic epidemiology and statistical terms, which will be referred to throughout the course. If you do not have any familiarity with epidemiology, be sure to watch this lecture.

Much of this content for this lecture was adapted from the course Bringing Change by Measuring Impact Health: Information Management and Applied Epidemiology for Health Care Workers in South Africa developed by I-TECH with the National Department of Health.


Downloads: Video (26 MB), Audio(9 MB), Transcript

Video: Study Designs Part 1 (23 minutes)

Watch this video lecture by Dr. Grace John-Stewart about different study designs and their advantages and disadvantages.


Downloads: Video (74 MB), Audio (24 MB), Transcript

Video: Study Designs Part 2 (14 minutes)

Watch this video lecture by Dr. Grace John-Stewart about randomized clinical trials.


Downloads: Video (36 MB), Audio (13 MB), Transcript

Activity: Study Designs (15 minutes)

This optional activity, which is ungraded, is a chance for you to see how well you can identify which study designs would best answer different types of research questions.

Video: Introduction to Qualitative Research (12 minutes)

Watch this video lecture by Dr. Kristin Beima-Sofie about qualitative research and how it differs from quantitative research.


Downloads: Video (41 MB), Audio (15 MB), Transcript

Discussion (20 minutes)

In the first discussion of the course, in 3-4 sentences, please introduce yourself to your group, briefly describe any research experience you have, and share what you hope to get out of this course.

Go to Discussion

*Please note that in this sample course, discussions are not available

Reading: Module Summary (5 minutes)

In this module, you learned some basic epidemiology terms, such as exposure and outcome, causality, bias, prevalence and incidence, and measures of association. The glossary includes the definition of these terms if you need to refer back to them later. 

Next, the module covered different types of study designs. There are some common questions that we start with to help design our studies. The first is “What is our question?” We could ask about the types of people who get a disease or condition, or when and where we observe more people with the disease or condition by using descriptive studies. These include case reports, case series, or surveys. Descriptive studies may be the first time a disease or condition is described to report something new. 

Another type of descriptive study is an ecological study, which compares a population’s outcome and a population’s exposure to determine if the two seem to be correlated. These kinds of studies are good for when it would be too difficult to collect individual-level data. 

Descriptive cross-sectional studies measure a population at one point in time to capture the exposure and outcome simultaneously. 

Analytic studies answer more in-depth questions about a disease or condition. They try to understand how and why some people have a disease or condition and other people do not. Cohort studies select people based on whether they do or do not have a specific exposure. Both groups are followed over time to see who develops the outcome of interest. 

In case control studies, people are selected to be included in the study based on whether they have the disease (cases) or do not have the disease (controls). Then we compare the past exposures between the two groups. 

In randomized clinical trials, or RCTs, we randomize people to different groups. In an RCT with two groups, one group receives an intervention and the other group does not receive an intervention, then we compare the outcomes between the two groups. These types of studies are considered the gold standard. Two kinds of RCTs are factorial clinical trials and community randomized trials. Factorial clinical trials have more than two groups, or arms arms. For example, if we are interested in two different interventions (A and B) we can assign one group to receive intervention A, one to receive intervention B, a third group that receives both intervention A and B, and a fourth group that receives neither intervention. In community randomized trials we compare groups, such as pairs of cities or regions, rather than individuals, and then randomly allocate one of the pairs to one of the two interventions. 

The last lecture discussed qualitative research, which can help us better understand a phenomenon or answer a question in more depth. Qualitative research relies on people’s experiences. It is primarily focused on answering questions about why, how, and under what circumstances something is happening using narratives. 

Quantitative and qualitative research can be combined in a mixed-methods approach using development, complementarity, and triangulation. In development, we use qualitative research to generate ideas or explore phenomena as a preliminary step. In complementarity, we would use qualitative research to delve deeper into findings from a quantitative study. With triangulation, we conduct quantitative and qualitative research simultaneously to concurrently validate our data. 

Finally, you learned about the different definitions of qualitative data and the important concepts of positionality and researcher reflexivity.

Quiz (15 minutes)

Go to Quiz

*Please note that there is no access to the quiz in this sample course.

Optional Resources

These readings reinforce the lecture and may clarify any concepts from the lecture you might not understand. 

Defining Research to Improve Health Systems. Remme, JHF. 2010. PLOS Medicine. 7:11 (7 pages). 

Combining Qualitative and Quantitative Sampling, Data Collection, and Analysis Techniques in Mixed‐Method Studies. Sandalowski, M. 2000. Research in Nursing & Health. 23:3. (9 pages).

Types of Study Designs
A table that compares different types of study designs.