When you are asked questions before you start a survey, or before you are invited to a focus group for market research you might notice that you are almost always asked a few questions before you can start the survey or be invited to a focus group.
Imagine the topic is banking. You'd be asked:
Do you or does anyone in your family work now or in the past in market research, advertising or media?
Do you now or did you ever work for a financial services provider?
If you said yes to either you would not be invited.
These are the basic questions and they're designed for two things. Sometime to keep the client's competition from learning about the client's plans or to ensure that the other focus group participants are comfortable voicing their opinions.
In the 20 years I spent organizing focus groups this never changed. We often asked our clients for clarification, or a bit of stretching the boundaries to make our job easier but not an area where there was flexibility.
When we asked for exceptions the answer we got was this:
As we go around the table and give each person a chance to speak and give their opinion, the dynamics of the discussion change dramatically after someone who is considered an expert gives an opinion on the topic of the group
No one wants to be at odds with the person who is seen to know more than the others because of experience. The person who 'knows the topic' has an overweight influence on the discussion whether they mean to or not.
I heard this point of view from another perspective at the HCSMCA Unconference in Vancouver. In a conversation with Dr. Paul Dempsey he talked about setting up a Moms group on his website so parents could support one another. He found that a lot of the wisdom of 'Dr. Mom' flowed among the participants - until he stepped in. The conversation stopped when he (the expert) stepped in.
This can make a difference when organizations, government or groups try to hear from patients.
Everyone's opinions are valid, but I would suggest that when there is a broad range of experience among patients, especially when some of the patients are or were health care professionals or health care workers, that holding separate focus groups would produce a better range of opinions and include more voices.