[gojomo]

Nowadays I believe an at-home "study" is more common, cheap, easy, and non-disruptive.

They give you a little case of sensors to take home & show you how you should attach them before bed. Chiefly it's a finger pulse oximeter & something worn on the chest to measure sleep orientation, chest motion, and record snoring sounds. You sleep as normal, at home, and return the devices the next day for its readings to be interpreted.

So: your concern about being in an unfamiliar setting, or being offered drugs to sleep, may be outdated. OTOH, if you're not in general risk groups nor experiencing daytime tiredness, there may not be not much reason to dig further (unless your wife has noticed something else worrisome).