A score of 12/24 or more is suggestive of OSA, and may need a Sleep Study done by a respiratory physician to be certain. A small home-diagnosing device called "Sleep Strip" can give you a guide as to the degree of OSA. They are available in New Zealand through "Care Medical" for around $80, ph 09-915 0800.
Snoring treatment using SnoreOp technology often reduces daytime sleepiness a great deal. One of our doctors who had quite severe OSA and daytime tiredness of around 17/24 found it reduced to 3/24, and now longer uses his CPAP machine.
...having been linked to depression, impotence, hypertension, falling asleep when driving, memory problems and other issues. Combined with Ischaemic Heart Disease, a heart attack can occur during the night.