When you develop an instrument that is to be used in different cultures, you have to pay a lot of attention to the cultural background and differential concepts, for instance what is to work successfully in a developing country like Brazil and what's to work successfully in a European city like Barcelona.

And this has to be worked in what we call focus groups. So we get around patients, they talk about the subject, and then we assess, we clinicians together with the patients, if what we mean by being functioning well is what they think is to be functioning well as well. So all this has to be worked, and it was a challenge to do that.

But there is a well-described methodology that comes from the social science field, that deals exactly with this type of challenge.

The methodology basically is to create those focus groups, so you have to work with the patients. And then after each of the questions of the instruments will be sent to each one of the centers that are developing the instrument. And then first the clinicians, we will assess if that is appropriate. Then they will discuss with the patients' group, and then we will like in a consensus validate the item or the question.