What is a protocol?
A systematic review protocol describes the rationale, hypothesis, and planned methods of the review. It should be prepared before a review is started and used as a guide to carry out the review.
Why register a systematic review protocol?
A systematic review protocol is important for several reasons:
Before moving forward with any systematic review, we recommend filling out a Systematic Review Protocol in PROSPERO or Open Science Framework. Systematic reviews are a time commitment, taking an average of 67.5 weeks or 15 months (see our Systematic Review Timeline page for an in-depth breakdown of the timeline/phases of a systematic review). Successfully filling out a protocol gives an insight into the amount of work that goes into a systematic review and may help increase chances of completing a systematic review. A registered systematic review protocol can also count as a citation.
Registering a protocol:
Systematic Reviews
Scoping Reviews
Shamseer, L., Moher, D., Clarke, M., Ghersi, D., Liberati, A., Petticrew, M., Shekelle, P., & Stewart, L. A. (2015). Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: Elaboration and explanation. BMJ, 349, g7647. https://doi.org/10.1136/bmj.g7647
What is the PICO format?
PICO is a format for developing a good clinical research question prior to starting one’s research. The PICO process starts with a case scenario from which a question is constructed that is relevant to the case and is phrased in such a way as to facilitate finding an answer. Once a well-structured question is formulated, researchers will be in a better position to search the literature for evidence that will support their original PICO question.
Part of the Acronym | Explanation | Example |
---|---|---|
P or Population | Who are the relevant patients or the target audience for the problem being addressed? | Adults (people over the age of 18) |
I or Intervention | What intervention is being considered? | Interactive social media, such as blogs and microblogs (e.g. Twitter), content communities (e.g. Youtube), virtual social networks (e.g. Facebook), and webpages and wiki |
C or Comparator | What is the main comparator to the intervention that you want to assess? | Non-interactive social media programs |
O or Outcome | What are the consequences of the interventions for the patient? Or what are the main outcomes of interest to the patient or decision maker? | Health behaviors, health, mental health, well-being, and whether people reported unwanted effects |
Other frameworks:
Question type | Framework |
Etiology/ Risk/ Benefit | PEO: Population, Exposure(s), Outcomes |
Prevalence/ Incidence | PCS: Population, Condition, Setting or context |
Diagnostic Test Accuracy | PIRD: Population, Index Test, Reference Test, Diagnosis of Interest |
Psychometric | PTM: Population, Type of measurement instrument, Measurement properties |
Read more:
Jensen, K. (2018, January 9). Seven Steps to the Perfect PICO Search. Health Notes. https://www.ebsco.com/blogs/health-notes/seven-steps-perfect-pico-search
Petkovic, J., Duench, S., Trawin, J., Dewidar, O., Pardo Pardo, J., Simeon, R., DesMeules, M., Gagnon, D., Hatcher Roberts, J., Hossain, A., Pottie, K., Rader, T., Tugwell, P., Yoganathan, M., Presseau, J., & Welch, V. (2021). Behavioural interventions delivered through interactive social media for health behaviour change, health outcomes, and health equity in the adult population. The Cochrane database of systematic reviews, 5(5), CD012932. https://doi.org/10.1002/14651858.CD012932.pub2
What is inclusion/exclusion criteria?
Inclusion and exclusion criteria should be established during protocol development or before proceeding with the searches. It is used to determine what studies from the comprehensive, reproducible searches will be used in your article to answer your research questions or objectives.
"The population, intervention and comparison components of the question, with the additional specification of types of study that will be included, form the basis of the pre-specified eligibility criteria for the review. It is rare to use outcomes as eligibility criteria: studies should be included irrespective of whether they report outcome data, but may legitimately be excluded if they do not measure outcomes of interest, or if they explicitly aim to prevent a particular outcome." (McKenzie et al., 2022)
Read more in Chapter 3: Defining the criteria for including studies and how they will be grouped for the synthesis
McKenzie JE, Brennan SE, Ryan RE, Thomson HJ, Johnston RV, Thomas J. Chapter 3: Defining the criteria for including studies and how they will be grouped for the synthesis. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). Cochrane, 2022. Available from www.training.cochrane.org/handbook.
Petkovic, J., Duench, S., Trawin, J., Dewidar, O., Pardo Pardo, J., Simeon, R., DesMeules, M., Gagnon, D., Hatcher Roberts, J., Hossain, A., Pottie, K., Rader, T., Tugwell, P., Yoganathan, M., Presseau, J., & Welch, V. (2021). Behavioural interventions delivered through interactive social media for health behaviour change, health outcomes, and health equity in the adult population. The Cochrane database of systematic reviews, 5(5), CD012932. https://doi.org/10.1002/14651858.CD012932.pub2
What is Grey Literature?
"Gray literature, or evidence not published in commercial publications, can make important contributions to a systematic review. Gray literature can include academic papers, including theses and dissertations, research and committee reports, government reports, conference papers, and ongoing research, among others. It may provide data not found within commercially published literature, providing an important forum for disseminating studies with null or negative results that might not otherwise be disseminated. Gray literature may thusly reduce publication bias, increase reviews’ comprehensiveness and timeliness, and foster a balanced picture of available evidence." (Paez, 2017)
Read more:
Paez, A. (2017). Gray literature: An important resource in systematic reviews. Journal of Evidence Based Medicine. 10(3), 233-240. https://doi.org/10.1111/jebm.12266
Critical Appraisal Tools:
Critical appraisal is an integral part of evidence-based medicine. It can also be referred to as "quality assessment" or "risk of bias". The organizations listed below offer a variety of checklists to help with the process of critically appraising evidence
Read more:
Downes, M. J., Brennan, M. L., Williams, H. C., & Dean, R. S. (2016). Development of a critical appraisal tool to assess the quality of cross-sectional studies (AXIS). BMJ Open, 6(12), e011458. https://doi.org/10.1136/bmjopen-2016-011458
Risk of bias tools—RoB 2 tool. (n.d.). Retrieved July 6, 2023, from https://www.riskofbias.info/welcome/rob-2-0-tool
Viswanathan, M., Patnode, C. D., Berkman, N. D., Bass, E. B., Chang, S., Hartling, L., Murad, M. H., Treadwell, J. R., & Kane, R. L. (2017). Assessing the Risk of Bias of Individual Studies in Systematic Reviews of Health Care Interventions. Agency for Healthcare Research and Quality. https://doi.org/10.23970/AHRQEPCMETHGUIDE2