Grigg-Damberger, in a recent review, 3 noted that there have been few complaints about the new scoring system. Moser and colleagues 4 found signifi cant differences in stage scores with the AASM Manual. Stages N1 and N3 were increased, whereas stage N2 was decreased with the new scoring as compared to the old. Scorers were drawn from a pool of 30 experienced sleep experts. Danker-Hopfe and colleagues found that use of the AASM Manual resulted in slightly improved inter-rater reliability to 82.0% compared to 80.6% using R & K rules. 5 Her study was based on 72 recordings that were scored with both methods by a pool of 7 experienced scorers.The AASM inter-scorer reliability (ISR) program was developed to aid sleep centers in fulfi lling accreditation standards. The standards require that a sample of randomly chosen records be scored by the center director and each of the technologists involved in record scoring. As a means of achieving this standard, the AASM ISR program provides a record each

How to obtain copies of this and other HTA Programme reports. An electronic version of this publication, in Adobe Acrobat format, is available for downloading free of charge for personal use from the HTA website (www.hta.ac.uk). A fully searchable CD-ROM is also available (see below).Printed copies of HTA monographs cost £20 each (post and packing free in the UK) to both public and private sector purchasers from our Despatch Agents.Non-UK purchasers will have to pay a small fee for post and packing. For European countries the cost is £2 per monograph and for the rest of the world £3 per monograph.You can order HTA monographs from our Despatch Agents:-fax (with credit card or official purchase order) -post (with credit card or official purchase order or cheque) -phone during office hours (credit card only).Additionally the HTA website allows you either to pay securely by credit card or to print out your order and then post or fax it. Contact details are as follows: Payment methods Paying by chequeIf you pay by cheque, the cheque must be in pounds sterling, made payable to Direct Mail Works Ltd and drawn on a bank with a UK address. Paying by credit cardThe following cards are accepted by phone, fax, post or via the website ordering pages: Delta, Eurocard, Mastercard, Solo, Switch and Visa. We advise against sending credit card details in a plain email. Paying by official purchase orderYou can post or fax these, but they must be from public bodies (i.e. NHS or universities) within the UK. We cannot at present accept purchase orders from commercial companies or from outside the UK. How do I get a copy of HTA on CD?Please use the form on the HTA website (www.hta.ac.uk/htacd.htm). Or contact Direct Mail Works (see contact details above) by email, post, fax or phone. HTA on CD is currently free of charge worldwide.The website also provides information about the HTA Programme and lists the membership of the various committees. HTA NIHR Health Technology Assessment ProgrammeT he Health Technology Assessment (HTA) Programme, part of the National Institute for Health Research (NIHR), was set up in 1993. It produces high-quality research information on the effectiveness, costs and broader impact of health technologies for those who use, manage and provide care in the NHS. 'Health technologies' are broadly defined as all interventions used to promote health, prevent and treat disease, and improve rehabilitation and long-term care. The research findings from the HTA Programme directly influence decision-making bodies such as the National Institute for Health and Clinical Excellence (NICE) and the National Screening Committee (NSC). HTA findings also help to improve the quality of clinical practice in the NHS indirectly in that they form a key component of the 'National Knowledge Service'. The HTA Programme is needs led in that it fills gaps in the evidence needed by the NHS. There are three routes to the start of projects. First is the commissioned route. Suggestions for research are actively sought from people working in...

Study Objectives: The American Academy of Sleep Medicine (AASM) Inter-scorer Reliability program provides a unique opportunity to compare a large number of scorers with varied levels of experience to determine agreement in the scoring of respiratory events. The objective of this paper is to examine areas of disagreement to inform future revisions of the AASM Manual for the Scoring of Sleep and Associated Events. Methods: The sample included 15 monthly records, 200 epochs each. The number of scorers increased steadily during the period of data collection, reaching more than 3,600 scorers by the fi nal record. Scorers were asked to identify whether an obstructive, mixed, or central apnea; a hypopnea; or no event was seen in each of the 200 epochs. The "correct" respiratory event score was defi ned as the score endorsed by the most scorers. Percentage agreement with the majority score was determined for each epoch and the mean agreement determined. Results:The overall agreement for scoring of respiratory events was 93.9% (κ = 0.92). There was very high agreement on epochs without respiratory events (97.4%), and the majority score for most of the epochs (87.8%) was no event. For the 364 epochs scored as having a respiratory event, overall agreement that some type of respiratory event occurred was 88.4% (κ = 0.77). The agreement for epochs scored as obstructive apnea by the majority was 77.1% (κ = 0.71), and the most common disagreement was hypopnea rather than obstructive apnea (14.4%). The agreement for hypopnea was 65.4% (κ = 0.57), with 16.4% scoring no event and 14.8% scoring obstructive apnea. The agreement for central apnea was 52.4% (κ = 0.41). A single epoch was scored as a mixed apnea by a plurality of scorers. Conclusions:The study demonstrated excellent agreement among a large sample of scorers for epochs with no respiratory events. Agreement for some type of event was good, but disagreements in scoring of apnea vs. hypopnea and type of apnea were common. A limitation of the analysis is that most of the records had normal breathing. A review of controversial events yielded no consistent bias that might be resolved by a change of scoring rules. I dentifi cation of respiratory events during sleep is critical to the diagnosis of sleep related breathing disorders, especially obstructive sleep apnea.1 Rules are provided by the AASM Manual for the Scoring of Sleep and Associated Events 2 (the Manual) and require not only identifi cation of events but classifi cation of types. Apnea types include obstructive, mixed, and central events. In addition, apneas are distinguished from hypopneas, defi ned as a partial decrease of air fl ow as measured using a nasal pressure transducer.Studies have attempted to assess scoring reliability for respiratory events, often employing non-standard techniques. A widely cited study published before the Manual used data from home sleep testing relying on a single nasal thermistor. 3The study defi ned apneas as a 75% or greater reduction of fl ow amplitude and hypopneas as a 30% or ...

RFCA is a relatively safe and efficacious procedure for the therapeutic treatment of AF and typical atrial flutter. There is some randomised evidence to suggest that RFCA is superior to AADs in patients with drug-refractory paroxysmal AF in terms of freedom from arrhythmia at 12 months. RFCA appears to be cost-effective if the observed quality of life benefits are assumed to continue over a patient's lifetime. However, there remain uncertainties around longer-term effects of the intervention and the extent to which published effectiveness findings can be generalised to 'typical' UK practice. All catheter ablation procedures for the treatment of AF or atrial flutter undertaken in the UK should be recorded prospectively and centrally and measures to increase compliance in recording RFCA procedures may be needed. This would be of particular value in establishing the long-term benefits of RFCA and the true incidence and impact of any complications. Collection of appropriate quality of life data within any such registry would also be of value to future clinical and cost-effectiveness research in this area. Any planned multicentre RCTs comparing RFCA against best medical therapy for the treatment of AF and/or atrial flutter should be conducted among 'non-pioneering' centres using the techniques and equipment typically employed in UK practice and should measure relevant outcomes.

Objective: To assess the cost-effectiveness of radiofrequency catheter ablation (RFCA) compared with antiarrhythmic drug (AAD) therapy for the treatment of atrial fibrillation (AF) from the perspective of the UK NHS. Design: Bayesian evidence synthesis and decision analytical model. Methods: A systematic review and meta-analysis was conducted and Bayesian statistical methods used to synthesise the effectiveness evidence from randomised control trials. A decision analytical model was developed to assess the costs and consequences associated with the primary outcome of the trials over a lifetime time horizon. Main outcome measure: Costs from a health service perspective and outcomes measured as quality-adjusted life years (QALYs). Results: The incremental cost-effectiveness ratio of RFCA varied between £7763 and £7910 for each additional QALY according to baseline risk of stroke, with a probability of being cost-effective from 0.98 to 0.99 for a cost-effectiveness threshold of £20 000. Results were sensitive to the duration of quality of life benefits from treatment. Conclusions: RFCA is potentially cost-effective for the treatment of paroxysmal AF in patients' predominantly refractory to AAD therapy provided the quality-of-life benefits from treatment are maintained for more than 5 years. These findings remain subject to limitations in the existing evidence regarding the nature of life benefits and the prognostic importance of restoring normal sinus rhythm conferred using RFCA.Atrial fibrillation (AF) is a common and debilitating cardiac arrhythmia. Its prevalence in the United Kingdom is rising as a result of an ageing population and an increased longevity resulting from improved medical care for chronic cardiac conditions which predispose to AF.1 A recent report estimated that approximately 1% of all NHS expenditures are the result of AF.2 The costeffective management of AF in the United Kingdom therefore represents an important consideration.Radiofrequency catheter ablation (RFCA) is an established technique for the treatment of cardiac arrhythmias, which has relatively recently been extended to allow treatment of AF. In the United Kingdom, its use for controlling AF is recommended by the National Institute for Health and Clinical Excellence (NICE) for patients who have previously failed on other management strategies.3 RFCA offers the potential to eliminate the underlying cause of AF, which other therapies fail to achieve. The primary outcome from the procedure is the restoration and maintenance of normal sinus rhythm (NSR). The sustained long-term maintenance of sinus rhythm establishes the efficacy of the intervention.RFCA results in significant upfront costs and a risk of procedural complications. However, the potential quality-of-life benefits through long-term absence of arrhythmia and any associated prognostic benefits (for example, reduced risk of stroke) may outweigh the costs when compared to longterm use of anti-arrhythmic drug (AAD) therapy and its associated adverse effects. Only one prev...