Assessment + Evaluation

I have another question about cognitive screens applicable to the acute care environment which is related to the previous MOCA question. I have developed a brief functional cognitive screen, essentially a collection of cognitive tasks with a scoring system that can be performed by a non-impaired person in 15 minutes. I am trying to set up a research design that compares it to the MOCA but need some third measure to compare them both to. I was thinking to have people perform a specific cognitively-demanding task which can be performed in bed but can't come up with anything. Does anyone have suggestions or recommendations for a useful way to set up a comparison for research purposes? I would very much appreciate any feedback.

Thanks,

Heather Sloman, Toronto, Canada