manual titration for obstructive sleep apnoea : automatic versus Continuous positive airway pressure titration

Background and aims Manual laboratory continuous positive airway pressure (CPAP) titration for obstructive sleep apnoea (OSA) is costly, time intensive and delays access to treatment. Automatic positive airway pressure (APAP) titration has the potential to reduce cost and improve access to treatment. The aim of this study was to assess the clinical efficacy and costs of APAP titration compared with manual titration in moderateesevere OSA. Methods Patients with moderateesevere OSA (apnoea/ hypopnoea index >15 and Epworth Sleepiness Score $8) who were free of co-morbidities that could impair APAP titration were eligible. 249 participants were randomised to manual titration, home APAP or laboratory APAP titration to determine a fixed pressure for CPAP. Clinical and direct cost outcomes were assessed after 4 weeks of treatment. Results Average nightly CPAP use, subjective sleepiness, SF36 quality of life, Trails A and B cognitive function and polysomnographic outcomes were similar among the per-protocol groups. Non-hypertensive patients had a lower resting heart rate (and greater reduction in heart rate) at 4 weeks after laboratory APAP titration compared with home APAP titration. Costs per patient were highest in manual (AU$817.84), followed by laboratory (AU$647.56) and home (AU$132.09) APAP titration. An intention-to-treat analysis confirmed the effectiveness of APAP titration compared with manual titration in the standard clinical setting. Conclusions Among patients with moderateesevere OSA without serious co-morbidities, outcomes at 1 month indicate that APAP titration is more cost-effective than manual laboratory titration to determine an appropriate pressure for CPAP for long-term use; with the largest savings occurring in the home APAP patients. Australian New Zealand Clinical Trials Registry Number ACTRN12608000054314. INTRODUCTION Obstructive sleep apnoea (OSA) is common, occurring to a clinically significant degree in 2e4% of the middle-aged population. OSA is associated with impaired quality of life and increased mortality from motor vehicle accidents and cardiovascular disease. There are a number of effective treatment options for OSA (including lifestyle advice and dental splint devices); however, the current standard of care for the majority of patients with moderateesevere OSA is nocturnal continuous positive airway pressure (CPAP). CPAP is usually set at a ‘fixed’ pressure sufficient to prevent upper airway collapse in all body positions and sleep stages. The reference standard for determining a fixed pressure for CPAP is an attended overnight CPAP titration study with full polysomnographic (PSG) monitoring in a sleep laboratory (ie, manual titration). Manual titration, however, is time consuming and costly, and is an important factor delaying access to effective treatment. Newer automatic positive airway pressure (APAP) devices are available which can control OSA by automatically adjusting pressure in response to device-measured physiological signals. The use of APAP titration to determine a fixed pressure for CPAP (which can subsequently be set on a standard CPAP machine) has the potential to reduce costs and improve access to treatment. A previous randomised controlled study validated the use of home APAP titration against manual titration on clinical outcomes for severe OSA (apnoea/hypoponea index (AHI) $30, Epworth Sleepiness Score (ESS) $12). In practice, the majority of patients with OSA treated with CPAP have moderate severity disease, but there are no data validating the use of APAP titration in patients with moderateesevere disease (AHI>15) against the reference standard of manual titration. Further, there is a paucity of randomised controlled data comparing costs of APAP titration with manual titration. We hypothesised that APAP titration would be as effective as manual titration among patients with moderateesevere OSA. We chose average nightly CPAP use as the a priori primary outcome. A secondary objective was to determine direct costs of the methods. METHODS We undertook a parallel group randomised controlled trial comparing manual titration, attended laboratory APAP and home APAP titration on clinical outcomes in moderateesevere OSA. Patient selection The source population were consecutive patients who were referred to a tertiary hospital sleep service (Western Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Perth, Western Australia), between March 2005 and December 2006, for possible OSA. All patients underwent a comprehensive clinical assessment by an experienced sleep physician and a full overnight laboratory PSG. The physician recorded whether there was a history of, or < Supplementary tables are published online only. To view these files please visit the journal online (http://throax.bmj.