We will randomise patients suspected to have OSA to either home evaluation and treatment (using a portable monitor and auto-CPAP) or in-lab evaluation with a PSG and manually-titrated CPAP. We will obtain sleep, sleepiness and quality of life questionnaires, vigilance testing and blood pressure at baseline and after 1, 2, 4 and 12 weeks of therapy. We will also assess and compare compliance with CPAP therapy in each arm of the study.