Loosing? Learn the English language, people!

More important than the specific expression is what model of disability you use. I'm not up-to-date now, but ten years ago, in English the term 'disabled people' was the term of choice because it was thought to better reflect the social model of disability (that people are disabled because society disables them, i.e. is not inclusive enough, not because of their specific impairment(s)). 'People with disabilities' was thought to reflect more the discredited medical model (people are disabled because there's something wrong with them).

It may be trend specific to Swedish how they're expressing themselves now, but in English, too, people were searching for better non-discriminatory language. For instance, some Deaf (with a capital D) people don't consider their deafness to be a disability but a bit of a gift that enables them to be part of a rich Deaf culture. 'Functional variation' may be an attempt to include disabled people and Deaf people, and possibly others, under the same term.