Treatment options depend on the degree of sleep apnoea, the impact that this is having on the individual and the presence of any other medical problems. The results of any sleep study have to be considered in light of these other factors.
The sleep studies count the number of apnoeas and hypopnoeas per hour (apnoea is cessation of breathing for 10 seconds or more hypopnoea is a reduction in airflow by 50% or more for 10 seconds or more). In order to be considered significant these events need to result in a drop in oxygen saturation (usually a 4% threshold) or fragmentation of sleep.
The number of apnoeas and hypopnoeas per hour is referred to as the Apnoea Hypopnoea Index (AHI) and the severity of the problem is graded as follows:
AHI <5per hour Normal Go to treatment for snoring
AHI 6-15 per hour Mild OSA Go to treatment for mild OSA
AHI 16-30 per hour Moderate OSA Go to treatment for moderate OSA
AHI >30 Severe OSA Go to treatment for severe OSA
Unfortunately these objective measures do not always correlate to the symptoms an individual experiences. Someone with mild OSA can be very sleepy during the day whereas another person with severe OSA may not feel at all compromised. Becuase the symptoms are so subjective it is possible that other factors influence how the patient reports the symptoms. A real concern is that a professional driver would seek to hide their sleepiness because of a fear that they will lose their job. In reality, whilst it may be necessary to stop driving for a couple of weeks whilst treatment is started, as long as they use the treatment they will be able to return to driving safely quite quickly. Sadly, all sleep specialists will have patients who have caused injury or death to other road users by falling asleep at the wheel.
General information about driving and medical problems http://www.dft.gov.uk/dvla/medical/about_dri_med.aspx
DVLA guidelines specific to sleep apnoea http://www.direct.gov.uk/en/Motoring/DriverLicensing/MedicalRulesForDrivers/MedicalA-Z/DG_185769