Research for Patient Benefit grants are great options for early and mid-career researchers who are looking for smaller pots of funding to consider. A real strength of the programme is the option to have co- principal investigators where an earlier career PI can be supported by a more experienced PI.
RfPB is researcher-led and does not specify topics for research.
You can find out more about current RfPB calls here: https://www.nihr.ac.uk/explore-nihr/funding-programmes/research-for-patient-benefit.htm