Clinical- and Cost-Effectiveness of a Mandibular Advancement Device Versus Continuous Positive Airway Pressure in Moderate Obstructive Sleep Apnea.

STUDY OBJECTIVES: Limited evidence exists on the cost-effectiveness of mandibular advancement device (MAD) compared to continuous positive airway pressure (CPAP) therapy in moderate obstructive sleep apnea (OSA). Therefore, this study compares the clinical and cost-effectiveness of MAD therapy with CPAP therapy in moderate OSA. METHODS: In a multicentre randomized controlled trial, patients with an apnea-hypopnea index (AHI) of 15 to 30 events/h were randomized to either MAD or CPAP. Incremental cost-effectiveness and cost-utility ratios (ICER/ICUR, in terms of AHI reduction and quality-adjusted life-years [QALYs, based on the EuroQol Five-Dimension Quality of Life questionnaire]) were calculated after 12 months, all from a societal perspective. RESULTS: In the 85 randomized patients (n = 42 CPAP, n = 43 MAD), AHI reduction was significantly greater with CPAP (median reduction AHI 18.3 [14.8-22.6] events/h) than with MAD therapy (median reduction AHI 13.5 [8.5-18.4] events/h) after 12 months. Societal costs after 12 months were higher for MAD than for CPAP (mean difference €2.156). MAD was less cost-effective than CPAP after 12 months (ICER -€305 [-€3.003 to €1.572] per AHI point improvement). However, in terms of QALY, MAD performed better than CPAP after 12 months (€33.701 [-€191.106 to €562.271] per QALY gained). CONCLUSIONS: CPAP was more clinically effective (in terms of AHI reduction) and cost-effective than MAD. However, costs per QALY was better with MAD as compared to CPAP. Therefore, CPAP is the first-choice treatment option in moderate OSA and MAD may be a good alternative. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Identifier: NCT01588275.

EEG coherence obtained from an auditory oddball task increases with age.

Changes in coherence with aging during cognitive tasks have, until now, not been investigated. However, several fMRI and positron emission tomography studies of cognitive tasks have found increased bilateral activity in elderly subjects. Changes in coherence with aging during a cognitive task were investigated to see if EEG coherence was present in older adults. An auditory oddball task, which is a widely used test for cognitive function, was used. Eleven young adults (27.8 +/- 4.8 years, six females) and 10 older adults (61.3 +/- 4.6 years, six females) were studied, and both interhemispheric and long- and short-range intrahemispheric coherence were considered. Higher interhemispheric coherence was found in the older subjects in the delta band. Short intrahemispheric coherence was also increased in the theta, delta, and alpha bands. Higher coherence, although not significantly different, was also found for all other coherence types and bands, except for long intrahemispheric coherence in the low gamma band. The results presented here provide the first evidence that aging is associated with increased EEG coherence during a relatively easy cognitive task.

P300 component identification in auditory oddball and novel paradigms using source analysis techniques: reduced latency variability in the elderly.

P300 latency variability in normal subjects limits its diagnostic applicability as a test for cognitive function. One of the causes of variation is the overlap in P300 (P3A and P3B) components resulting in inaccurate latency determination. Recently, we have shown that identification of P3A and P3B components using source analysis techniques significantly reduces P300 latency variability in healthy younger subjects. Here, we included a novel paradigm to enhance sensitivity and investigated the efficiency of the source analysis technique in reducing the P300 latency variability in healthy older subjects. Data were recorded with a 128-channel EEG system in 28 healthy subjects (aged 53-82 years, 12 males). We used a standard two-tone and a novel three-tone auditory oddball paradigm and an established source analysis technique, and compared the latencies to those obtained with conventional P300 analysis. The source analysis method identified both P3A and P3B components in a substantially larger percentage of subjects (93% versus 32%) than the conventional method. Both for the standard and novel paradigm, the source analysis method yielded a later mean P3B latency (361.4 versus 344.2 milliseconds, P = 0.017, and 374.4 milliseconds versus 354.3 milliseconds, P = 0.014, respectively) with a smaller standard deviation (15.8 versus 26.2 milliseconds, P = 0.013, and 18.9 versus 30.0 milliseconds, P = 0.052, borderline significant, respectively) than the conventional P300 method, for subjects aged 50 to 70 years. When applying the source analysis technique, as in young healthy subjects, a considerable reduction of P300 latency variability was thus found in healthy older subjects aged 50 to 70 years for both paradigms. This may have important consequences for applications of clinical event-related potential research in the early diagnosis of dementia, because the first signs of this disease are mostly observed in this age category.