I normally have to do a sleep study every renewal as although I show NO signs of Sleep Apnea my BMI is 31 (limit 30 when over 40 years old) , neck circumference is 43cm (limit 42 when over 42 years old) and I am over 40 years old. For 3 years in a row now the sleep studies have all shown that I don't snore, and do not have sleep apnea. Yet every year I know its coming, I have to admit I have never found CASA to be too bad with the processing times etc, I can normally get the study done within the two month medical extension resulting in no down time. I did peak at a BMI of 35 which through a lot of lifestyle change is slowly coming down, I am realistic in that I know that as long as I am above the acceptable limits this is just what has to be done. The studies that I have done are just at home, self administered and you then send the machine back to the clinic who processes it and sends all of the results through to the DAME, it takes around a week.