When conducting evidence synthesis, many people use the PICO framework. PEAK means
population; Yointervention; docomparator(s); and ohresult. This helps describe the research question that the evidence synthesis aims to answer. However, recently Remiro‐Azócar (2024) proposed PICOSI framework. PICOSI means:
- Ppopulation
- Yointervention
- docomparator(s)
- ohresults
- Yessummary effect measure;
- Yointercurrent events
In fact, Recent draft methods guideline from the Canadian Drug Agency (CDA) recommends the use of PICOSI when defining a target estimate. While the first five components are familiar to many, the intercurrent events are less well known. CDA defines this as:
…intercurrent events refer to those events of interest that occur after treatment has been initiated and that may affect the interpretation of the endpoint that quantifies the treatment effect (e.g., the event modifies the treatment effect, such as in the use of rescue medications or other concomitant events). treatments, or has implications for compliance with the treatment regimen, including premature discontinuation of treatment)
The difference is important because the perspectives of regulators and payers differ.
The HTA paradigm places emphasis on evaluating “real-world” effectiveness, while regulators generally prioritize internal validity over external validity when evaluating clinical effectiveness… HTA policy decisions generally consider external validity, but external validity depends on the population targeted by the payer.
In the figure below, the CDA describes the different types of evidence that can be used within an evidence synthesis exercise for HTA purposes.
Read more about the CDA methods guide for technology assessment here.
