As with any project, the first step is to have a goal - generally the answer(s) to a research question;  a well-defined and specific research question is key to reaching that goal.

 To support development of the research question, your team may:

(1) run exploratory searches,

(2) speak with others in your field, and/or

(3) gather input from stakeholders such as policy makers and community members who may be interested in the findings of your evidence synthesis project. 

Research question development is not straight forward and will require time and iteration and team involvement.

Research Question Development Tools (e.g., PICO)

Research question development tools, also called 'research question formulation frameworks' or 'concept developers' are simply acronyms that help you consider the details behind your research question. 

The intervention-focused tool PICO, which stands for Population, Intervention, Comparator, and Outcome, is a common example used in systematic reviews. However, you have many more options including the 5W's and H, SPIDER, and CIMO. Review the Question Formulation Frameworks module below for some other common research question development frameworks.

Your team would like to know if/how socioeconomic factors that lead to health disparities lead to a risk of late diagnosis of colorectal cancer. An intervention your team may consider is holding screening events and follow ups with patients. The outcome of interest is raising awareness about colorectal cancer.       PICO:  Population: groups with socioeconomic factors leading to health disparities in the United States Intervention: screening events and follow ups with patients Comparator: compared to no intervention Outcome: awareness of colorectal cancer; likelihood of early diagnosis in order to improve likelihood of successful treatment 5W’s and H: Who: groups with socioeconomic factors leading to health disparities What: awareness and diagnosis of colorectal cancer When: studies must include a measurement of the frequency of contact with patients through the intervention Where: studies must be conducted in the United States How: screening events and follow ups with patients Refined Research Question:  Do screening events and follow ups with patients (How/Intervention) increase early diagnosis of colorectal cancer (What/Outcome) for individuals with socioeconomic factors/health disparities in the United States (Who/Population) as compared to no intervention (Comparator)?

Credit: "Research Question" (Virginia Tech University Libraries) used by OSU Libraries & Press under CC BY-NC-SA 4.0

Beyond the research question frameworks presented above, Hosseini et al. (2024) offer a more extensive list of frameworks.

References:

• Hosseini, M.-S., Jahanshahlou, F., Akbarzadeh, M. A., Zarei, M., & Vaez-Gharamaleki, Y. (2024). Formulating research questions for evidence-based studies. Journal of Medicine, Surgery, and Public Health, 2, 100046-. https://doi.org/10.1016/j.glmedi.2023.100046

Eligibility Criteria

Eligibility criteria are also called inclusion and exclusion criteria. Think of it as an extension of your research question that clearly identifies:

Inclusion Criteria or the set of characteristics that a study must have to be included in the final synthesis.

Exclusion Criteria or the set of characteristics that, if present, would make the study ineligible to be included in the final synthesis.

Eligibility criteria must be defined before starting the review, thus reducing the likelihood of having to make ad hoc decisions during the review which contributes to bias.

Note about Language Limits

It is common to find eligibility criteria in systematic reviews that exclude articles outside of the languages of those in the team. In the US, this often means "English only" articles are included. However, this exclusion poses a serious risk of bias toward research produced by countries where English is a dominant language. Therefore, it is best to avoid excluding based on language when you can. 

A 2019 article (Jackson et al.)  concludes that "Google Translate is a viable, accurate tool for translating non–English-language trials for the purpose of conducting systematic reviews."

Of course accuracy would be likely to vary if this study was conducted with articles in different disciplines, languages, or using publication-type, but it's a great start and better than simply excluding other languages altogether.

Credit: "Eligibility Criteria" (Virginia Tech University Libraries) adapted by OSU Libraries & Press used under CC BY-NC-SA 4.0.

References:

• Jackson, J. L., Kuriyama, A., Anton, A., Choi, A., Fournier, J.-P., Geier, A.-K., Jacquerioz, F., Kogan, D., Scholcoff, C., & Sun, R. (2019). The Accuracy of Google Translate for Abstracting Data From Non–English-Language Trials for Systematic Reviews. Annals of Internal Medicine, 171(9), 677–679. https://doi.org/10.7326/m19-0891.

• Thomas J, Kneale D, McKenzie JE, Brennan SE, Bhaumik S. (2023, August). Chapter 2: Determining the scope of the review and the questions it will address. In J.P.T. Higgins, J. Thomas, J. Chandler, M. Cumpston, T. Li, M.J. Page, & V.A. Welch (Eds). Cochrane Handbook for Systematic Reviews of Interventions (version 6.5, 2024). www.training.cochrane.org/handbook.