PISO and CIMO frameworks

Have you heard of PISO and CIMO before? Well, if not, they stand for population, intervention, study design, outcome; and context, intervention, mechanism, outcome (Cochrane Library, 2025; Costa et al., 2018).

PISO (Cochrane Library, 2025) is:

• Population (or Patient or Problem): "What are the characteristics of the patient or population (demographics, risk factors, pre-existing conditions, etc)? What is the condition or disease of interest?"
• Intervention: "What is the intervention under consideration for this patient or population?" So what are we going to do, treat, change, or action?
• Study design: "What is the alternative to the intervention (e.g. placebo, different drug, surgery)?" What else will we consider, and how will we plan this?
• Outcome: "What are the included outcomes (e.g. quality of life, change in clinical status, morbidity, adverse effects, complications)?" What do we expect to happen, what would we like to happen? How will we measure and know if this has worked?

CIMO (Costa et al., 2018, p. 3) is:

• Context: "The results that human actors aim to achieve and the surrounding (external and internal environment) factors that influence the actors". What are the circumstances or environment where we research the intervention?
• Intervention: "Purposeful actions or measures (products, processes, services or activities) that are formulated by the designer or design team to solve a design problem or need, and to influence outcomes". What is the action or change we introduced into the situation?
• Mechanism: "The mechanism that is triggered by the intervention, in a certain context, by indicating why the intervention produces a certain outcome. It can be an explanation of the cognitive processes (reasoning) that actors use to choose their response to the intervention and their ability (resources) to put the intervention into practice". How will/might the intervention work? Quantitative research will be in order to produce the outcomes in the next step; qualitative will be more "how might the intervention work?" and being open on outcomes.
• Outcome: "Result of the interventions in its various aspects". What did we ended up with; what were the impacts of the intervention?

The key differences between these concepts is that PISO is more likely to be used in clinical or experimental research designs, and often in healthcare. PISO tends to emphasise who is being studied and how (Cochrane Library, 2025). On the other hand, CIMO is a management and social science tool, seeking to understand why and how interventions work in specific contexts or cases (Costa et al., 2018). Either framework will assist in systematic reviews as well as evidence-based research projects. 

Following either a PISO or CIMO framework assists researchers in how to ask their research question (or questions), what type of methodologies, methods and data collection should be chosen, determining variables, and analysing and organising findings.

Anything that helps us to create stronger, more deliberate ways of researching has to be a bonus!

Sam

References:

Cochrane Library. (2025). What is PICO?. https://www.cochranelibrary.com/about-pico

Costa, E., Soares, A. L., & de Sousa, J. P. (2018). Exploring the CIMO-logic in the design of collaborative networks mediated by digital platforms [paper]. Collaborative Networks of Cognitive Systems (19th IFIP WG 5.5 Working Conference on Virtual Enterprises), PRO-VE 2018, Cardiff, UK, September 17-19. https://doi.org/10.1007/978-3-319-99127-6_23