I like @dimitris answer, but I would add two shorter options : « usage réel » and « utilisation réelle » which are both perfectly understandable in French.

My attempt at translating the full sentence :

Comprendre dans quelle mesure l’[usage réel / utilisation réelle] est
comparable aux données de suivi.

I agree with this answer about usage réel or utilisation réelle, especially in the example sentence provided. I think it is the best choice.

I just wanted to offer an alternative, which might not be appropriate in this specific example, but could work well elsewhere.

Common in Quebec, though I am unsure about other areas of the Francophony, is “dans la vraie vie”. It is familiar, though not offensive enough to justify claiming it should be avoided in speech, even in a formal presentation :

It’s all nice and good on paper, but in real world usage, people will almost always use “on” instead of “nous”.

…could become :

C’est bien beau sur papier, mais dans la vraie vie, les gens utilisent pratiquement toujours « on » plutôt que « nous »