I agree with Squidwrath 100%, and am thinking of requesting a study of my own. (I suffer from restless legs syndrome at times.)
My husband had the sleep test done, and after less than two hours (and over 100 episodes of apnea) they woke him and fitted him with a mask right then and there. The monitor was rattled and did not want him to continue the rest of the night struggling while she watched. He slept the rest of the night with the mask, monitored, and said he actually felt a difference the next day. Within three days of being able to use the mask all night long (took some adjustment) he felt much much better.
He would recommend it to anyone who feels they are not getting adequate rest. He was very hesitant to attempt to sleep away from home while monitored, but it went fine. I should mention that he does not have fibro, but he ended up in the ER with "the worst headache of his life" from skyrocketing blood pressure from the lack of sleep. His GP told him that he was lucky not to have died in his sleep prior to testing. The report was that bad.
And FYI - The entire thing was covered by our insurance, including the equipment.