Table 4 Common themes, subthemes and quotes identified in response to the questions “What do you think the biggest benefit/biggest limitation is of PPI in statistical methodology work?” from “Conclusions” section of the questionnaire

Biggest benefit

Shapes the research question

“To determine whether the question you are trying to answer is actually relevant/interesting to patients/public or not or whether research would be better focused elsewhere.” (P6)

Shapes the methods used

“Helpful in developing accurate statistical methodology.” (P121)

“Patient relevant metrics developed.” (P62)

Reduces research waste

“Making sure that the methodology has an ultimate purpose, rather than wasting funds on somebody’s pet project that won’t have any impact on patient care (no matter how far away that impact is).” (P54)

Impact on patients

“Helping to ensure the research we conduct is having the best possible impact on patients/public.” (P81)

“It might be useful to have patient input into whether the new methodology could actually lead to something patients think is useful.” (P69)

Aids communication of research

“Improved communication of new methods: when you’re working on something you already “get it”, so it’s good for outside input on whether explanations are clear.” (P108)

“Challenges methodologists to communicate research to broader audiences and consider how their research is important to end users.” (P23)

Offers new perspectives

“Receiving insights from patients and members of the public: they bring aa whole new perspective and dimension to research, and are likely to contribute observations from their personal experience that academics have not considered.” (P65)

Ensures research is relevant

“PPI allows us to ask the correct questions that are relevant and important to patients.” (P42)

Makes research reflective of real-world experience

“In the context of causal inference, regulatory bodies are open to incorporating real-world evidence into their decision making. So PPI would be useful if you thought of your causal analysis as an emulation of a clinical trial.” (P19)

“Grounding the research in reality, and focusing them on what matters most to patients and/or public.” (P91)

Transparency

“Transparency about what we do and how we do it.” (P13)

For funding purposes

“Not clear there is one beyond appeasing funders.” (P40)

Ticks a box

“May tick a formal box for funders” (P21)

“Box ticking” (P114)

Improving statisticians’ reputation

“Communicating to public that statisticians are highly skilled and research methodology is more complex than most people realise, i.e. PR for statisticians rather than gaining useful feedback.” (P38)

“I see very limited benefit of PPI in this domain” (P93)

No benefit/not sure

“I have struggled to identify one in the pieces of work I have worked on” (P96)

“Great way to waste money” (P32)

Biggest limitation

Finding the right participants

“Finding the right level of understanding for a member of the public to be able to comment in a useful way without overloading/confusing them.” (P4)

“Potential overrepresentation of included groups vs excluded groups.” (P39)

“Finding people! Very different from clinical trials, where patients and/or patient groups and/or charities are a natural place to find people.” (P76)

Relevance

“Patient’s opinions don’t affect how well treatments work, which is what statistical methods should be accurately measuring.” (P119)

“Adopting a ‘one size fits all’ approach to PPI. There are projects where members of the public are unlikely to be able to offer meaningful advice without specialist training—when this is the case the project should not be penalised/judged “harshly by grant bodies/journals, universities etc.” (P116)

“Hard to see how patients can inform design of simulations comparing different methods. Practical benefits tend to come in later down the line when a researcher wants to develop a model in practice and is deciding the type of model to develop and how to do so.” (P96)

Using PPI effectively

“It is really tricky to know how to do it meaningfully and not just for the sake of it.” (P81)

“There is a huge focus on the process not the benefits making it difficult for researchers to focus on the advantages it confers on statistical methodology work.” (P35)

Communicating to PPI members

“It is challenging/time consuming to appropriately explain to patients/public what you are doing in order to get beneficial feedback” (P6)

“Difficult to even explain the problem, let alone the solution.” (P2)

Funding for PPI

“Funding to support grant development.” (P20)

Finding the time

“Time and understanding.” (P46)

Methodologists’ attitudes

“Persuading statisticians to listen and learn.” (P99)

Complexity of methods

“I am not sure that PPI representatives can legitimately comment on complex methodological issues.” (P84)

“Although I think PPI should be encouraged for some statistical methodology work, I think mandating it could be another barrier when methodology projects are already difficult to get funded. Would often require explanation of complex ideas/methods which may be difficult to convey in a short amount of time (or of little interest to members of the public without a STEM background). (P110)