Hi Steve,
I'm not saying this is a scam by any means. It may well be that Acumen have been retained by a medical company (an insulin pen manufacturer for example) to ask questions on behalf of that company. But Acumen's objective will be to get you onto their database - that's how they make their money. As Ken said, they have to dress it up in some way - would you consider going if they simply said we want to profile you so we can sell your details on?
Believe me, I have worked for several companies who use similar market research operations. In each case my company genuinely wanted feedback or public opinion on particular products, but the end result is that the participants details are sold on by the market researchers. Providing up to date information on people is a hugely profitable business, and how more up to date can you get than someone who you have just interviewed and has given you all their information.
I'm not saying don't go, but just be aware that gathering information on insulin pens is almost certainly a secondary consideration by Acumen.