Effect of switching from continuous to bilevel positive airway pressure on sleep quality in patients with obstructive sleep apnea: the prospective POP IN VAuto study.

Background: Issues with tolerability and side effects can decrease continuous positive airway pressure (CPAP) device usage and the benefits of therapy. Different positive airway pressure (PAP) therapy modes providing expiratory pressure relief or using a different pressure during inspiration vs. expiration (bilevel PAP) may alleviate some of these issues. This multicenter, prospective study evaluated the effects of switching from CPAP to bilevel PAP (VAuto mode) on respiratory parameters, device usage, side effects and patient-reported outcomes in patients with obstructive sleep apnea (OSA). Methods: Eligible OSA patients had started CPAP ≥3 months previously, had good compliance (mean 6.1±2.0 h/night) and well-controlled OSA [residual apnea-hypopnea index (AHI) 4.9±3.1/h] but had pressure tolerance issues or persistent side effects/discomfort. All were switched from CPAP to bilevel PAP (AirCurve 10 VAuto; ResMed). Effectiveness (residual AHI), sleep quality, daytime sleepiness, fatigue, therapy-related side effects, and patient satisfaction/preference were assessed after 3 months and 1 year. Results: Forty patients were analyzed (68% male, age 64±11 years, body mass index 30.7±5.8 kg/m2). At 3 months and 1 year after switching to bilevel PAP, median [interquartile range] residual AHI was 4/h [2-5.3] and 3.7/h [1.8-5], respectively, and device usage was 7.0 [4.9-7.5] and 6.4 [4.4-7.3] h/night, respectively. Device switch was associated with significant reductions from baseline in expiratory PAP {from 12 [11-13] to 8 [7-9] cmH2O at 3 months (P<0.001) and 9 [8-12] cmH2O at 1 year (P=0.005)}, 95th percentile pressure {from 14 [12-14] to 10 [9-11] and 10 [8-11] cmH2O; P<0.001 and P=0.001, respectively} and leak {from 1 [0-6] to 0 [0-1] and 0 [0-2] L/min; P=0.049 and P=0.033, respectively}. The Pittsburgh Sleep Quality Index score decreased significantly from baseline to 3 and 6 months [7.2±4.0 to 5.0±3.2 (P=0.005) and 4.5±2.7 (P<0.001), respectively]. CPAP-related mouth dryness, choking sensation and aerophagia were significantly improved one year after switching to bilevel PAP. Bilevel PAP was preferred over CPAP by 90% of patients. Conclusions: Switching to bilevel PAP had several benefits in patients struggling with CPAP, facilitating therapy acceptance and ongoing device usage.

A multi-intervention protocol to improve sleep quality in a coronary care unit.

AIMS: Poor sleep is a frequent occurrence in the critical illness. Evaluate sleep quality and test the effect of a multi-intervention sleep care protocol in improving sleep quality in a coronary care unit (CCU). METHODS AND RESULTS: Quasi-experimental study, carried out in two phases. During the first phase, the control group (n = 58 patients) received usual care. Baseline sleep data were collected through the Richards-Campbell Sleep Questionnaire (RCSQ) and the Sleep in the Intensive Care Unit Questionnaire (SICUQ). During the second phase (n = 55 patients), a sleep care protocol was implemented. Interventions included actions to promote analgesia, reduce noise, brightness, and other general measures. Sleep data were collected again to assess the impact of these interventions. The intervention group had better scores in overall sleep depth [median (interquartile range)] [81 (65-96.7) vs. 69.7 (50-90); P = 0.046]; sleep fragmentation [90 (65-100) vs. 69 (42.2-92.7); P = 0.011]; return to sleep [90 (69.7-100) vs. 71.2 (40.7-96.5); P = 0.007]; sleep quality [85 (65-100) vs. 71.1 (49-98.1); P = 0.026]; and mean RCSQ score [83 (66-94) vs. 66.5 (45.7-87.2); P = 0.002] than the baseline group. The main barriers to sleep were pain [1 (1.0-5.5)], light [1 (1.0-5.0)], and noise [1 (1.0-5.0)]. The most rated sources of sleep-disturbing noise were heart monitor alarm [3 (1.0-5.25)], intravenous pump alarm [1.5 (1.0-5.00)]. and mechanical ventilator alarm [1 (1.0-5.0)]. All were significantly lower in the intervention group than in the baseline group. CONCLUSION: A multi-intervention protocol was feasible and effective in improving different sleep quality parameters and reducing some barriers to sleep in CCU patients.

Bilateral hypoglossal nerve stimulation for treatment of adult obstructive sleep apnoea.

BACKGROUND AND AIM: Hypoglossal nerve stimulation (HNS) decreases obstructive sleep apnoea (OSA) severity via genioglossus muscle activation and decreased upper airway collapsibility. This study assessed the safety and effectiveness at 6 months post-implantation of a novel device delivering bilateral HNS via a small implanted electrode activated by a unit worn externally, to treat OSA: the Genio™ system. METHODS: This prospective, open-label, non-randomised, single-arm treatment study was conducted at eight centres in three countries (Australia, France and the UK). Primary outcomes were incidence of device-related serious adverse events and change in the apnoea-hypopnoea index (AHI). The secondary outcome was the change in the 4% oxygen desaturation index (ODI). Additional outcomes included measures of sleepiness, quality of life, snoring and device use. This trial was registered with ClinicalTrials.gov, number NCT03048604. RESULTS: 22 out of 27 implanted participants (63% male, aged 55.9±12.0 years, body mass index (BMI) 27.4±3.0 kg·m-2) completed the protocol. At 6 months BMI was unchanged (p=0.85); AHI decreased from 23.7±12.2 to 12.9±10.1 events·h-1, a mean change of 10.8 events·h-1 (p<0.001); and ODI decreased from 19.1±11.2 to 9.8±6.9 events·h-1, a mean change of 9.3 events·h-1 (p<0.001). Daytime sleepiness (Epworth Sleepiness Scale; p=0.01) and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire-10; p=0.02) both improved significantly. The number of bed partners reporting loud, very intense snoring, or leaving the bedroom due to participant snoring decreased from 96% to 35%. 91% of participants reported device use >5 days per week, and 77% reported use for >5 h per night. No device-related serious adverse events occurred during the 6-month post-implantation period. CONCLUSIONS: Bilateral HNS using the Genio™ system reduces OSA severity and improves quality of life without device-related complications. The results are comparable with previously published HNS systems despite minimal implanted components and a simple stimulation algorithm.

Effect of mandibular advancement therapy on inflammatory and metabolic biomarkers in patients with severe obstructive sleep apnoea: a randomised controlled trial.

Systemic inflammation and metabolic disorders are among the mechanisms linking obstructive sleep apnoea (OSA) and cardiovascular disease (CVD). In 109 patients with severe OSA and no overt CVD, biomarkers of inflammation (C reactive protein, interleukin-6, tumour necrosis factor-α and its receptors, adiponectin, leptin and P-selectin), glucose and lipid metabolism, and N-terminal pro-brain natriuretic peptide, were measured before and after 2 months of treatment with a mandibular advancement device (MAD) (n=55) or a sham device (n=54). MAD reduced the Apnoea-Hypopnoea Index (p<0.001) but had no effect on circulating biomarkers compared with the sham device, despite high treatment adherence (6.6 hour/night). TRIAL REGISTRATION NUMBER: NCT01426607.

Comparison of titrable thermoplastic versus custom-made mandibular advancement device for the treatment of obstructive sleep apnoea.

BACKGOUND AND OBJECTIVES: The disadvantages of custom-made mandibular advancement devices (MAD) for obstructive sleep apnoea (OSA) therapy are the cost and delay required to manufacture the device. This study aimed to evaluate the efficacy of a titrable, thermoplastic MAD compared to a custom-made MAD for OSA therapy. METHODS: In this prospective nonrandomized study, 158 patients with OSA from two French sleep centers were treated for 6 months with a titrable thermoplastic MAD (n = 86) or a custom-made MAD (n = 72). The primary outcome was the change in sleep-disordered breathing (SDB) severity. RESULTS: After adjustment for baseline values, age, body mass index and study site, no significant intergroup differences were observed between thermoplastic and custom-made MAD for the outcome of apnoea, hypopnoea and oxygen desaturation indices. No between treatment differences were observed for the outcome of subjective sleepiness, symptoms of snoring and fatigue, depressive symptoms, and quality of life. Thermoplastic MAD therapy was associated with higher side effects scores for tooth pain (p < 0.0001) and self-reported occlusal changes (p = 0.0069). Mean (SD) reported compliance was lower in the thermoplastic MAD group than in the custom-made MAD group (6.4 [0.2] vs 7.1 [0.1] h/night; p = 0.035). CONCLUSIONS: This study demonstrates the efficacy of a titrable thermoplastic MAD in reducing SDB and related symptoms in patients with mild to severe OSA. Reported compliance at 6 months was high despite more dental discomfort than with custom-made MAD.

Performance characteristics of the French version of the severity hierarchy score for paediatric sleep apnoea screening in clinical settings.

BACKGROUND: Paediatric obstructive sleep apnoea syndrome (OSAS) is a highly prevalent condition carrying increased risk for impaired cognitive and cardiovascular function. The standard diagnosis consists of full-night polysomnography (PSG), but limited access to PSG leads to substantial under-diagnosis. The use of a validated and simple diagnostic screening tool to predict OSAS could prioritise night sleep recordings in children at risk of OSAS, and help in clinical decision-making. OBJECTIVE: This study aimed to prospectively assess the performance of the French version of the severity hierarchy score (SHS) in paediatric OSAS. This score consists of a discriminative subset of six respiratory items, and has already been validated in English for screening OSAS in the general paediatric population. METHODS: A total of 96 children (mean age 7.1 ± 2.4 years; BMI z-score: -0.03 ± 1.50) were recruited; they had been were referred to two academic sleep centres in France for the putative diagnosis of sleep-disordered breathing. The parents completed the SHS questionnaire prior to PSG. Sensitivity and specificity of the SHS for detecting moderate OSAS, defined by an apnoea-hypopnoea index (AHI) of ≥5/hours of total sleep time (TST), were assessed, and ROC analysis was performed. RESULTS: An SHS score of >2.75 exhibited an 82% sensitivity, 81% specificity, and 92% negative predictive value for detecting an AHI of ≥5/hour TST in the cohort. CONCLUSION: The French version of the SHS emerged as favourably suited for the screening for OSAS in children.

Impact of Mandibular Advancement Therapy on Endothelial Function in Severe Obstructive Sleep Apnea.

RATIONALE: Endothelial dysfunction, a major predictor of late cardiovascular events, is linked to the severity of obstructive sleep apnea (OSA). OBJECTIVES: To determine whether treatment with mandibular advancement device, the main alternative to continuous positive airway pressure, improves endothelial function in patients with severe OSA. METHODS: In this trial, we randomized patients with severe OSA and no overt cardiovascular disease to receive 2 months of treatment with either effective mandibular advancement device or a sham device. The primary outcome, change in reactive hyperemia index, a validated measurement of endothelial function, was assessed on an intention-to-treat basis. An embedded microsensor objectively measured treatment compliance. MEASUREMENTS AND MAIN RESULTS: A total of 150 patients (86% males; mean [SD] age, 54 [10] yr; median [interquartile range] apnea-hypopnea index, 41 [35-53]; mean [SD] Epworth sleepiness scale, 9.3 [4.2]) were randomized to effective mandibular advancement device (n = 75) or sham device (n = 75). On intention-to-treat analysis, effective mandibular advancement device therapy was not associated with improvement of endothelial function compared with the sham device. Office and ambulatory blood pressure outcomes did not differ between the two groups. Effective mandibular advancement device therapy was associated with significant improvements in apnea-hypopnea index (P < 0.001); microarousal index (P = 0.008); and symptoms of snoring, fatigue, and sleepiness (P < 0.001). Mean (SD) objective compliance was 6.6 (1.4) h/night with the effective mandibular advancement device versus 5.6 (2.3) h/night with the sham device (P = 0.006). CONCLUSIONS: In moderately sleepy patients with severe OSA, mandibular advancement therapy reduced OSA severity and related symptoms but had no effect on endothelial function and blood pressure despite high treatment compliance. Clinical trial registered with www.clinicaltrials.gov (NCT 01426607).

Sleep in the intensive care unit / Sono na unidade de terapia intensiva

ABSTRACT Poor sleep quality is a consistently reported by patients in the ICU. In such a potentially hostile environment, sleep is extremely fragmented and sleep architecture is unconventional, with a predominance of superficial sleep stages and a limited amount of time spent in the restorative stages. Among the causes of sleep disruption in the ICU are factors intrinsic to the patients and the acute nature of their condition, as well as factors related to the ICU environment and the treatments administered, such as mechanical ventilation and drug therapy. Although the consequences of poor sleep quality for the recovery of ICU patients remain unknown, it seems to influence the immune, metabolic, cardiovascular, respiratory, and neurological systems. There is evidence that multifaceted interventions focused on minimizing nocturnal sleep disruptions improve sleep quality in ICU patients. In this article, we review the literature regarding normal sleep and sleep in the ICU. We also analyze sleep assessment methods; the causes of poor sleep quality and its potential implications for the recovery process of critically ill patients; and strategies for sleep promotion.

RESUMO O sono de má qualidade é uma situação persistentemente descrita em UTIs. O sono nesse ambiente potencialmente hostil é caracterizado pela sua extrema fragmentação e arquitetura não convencional, com predomínio de fases leves e limitada quantidade de tempo nos estágios reparadores. Entre as causas da privação do sono na UTI estão fatores intrínsecos aos pacientes e à condição aguda de sua doença, assim como fatores relacionados ao ambiente da UTI e ao tratamento em curso, como o suporte ventilatório e a terapia medicamentosa. Embora as consequências da má qualidade do sono no processo de recuperação desses pacientes ainda sejam desconhecidas, ela parece influenciar os sistemas imune, metabólico, cardiovascular, respiratório e neurológico. Evidências sugerem que intervenções multifacetadas, focadas na minimização das perturbações do sono noturno, promovem melhora na qualidade do sono nesses pacientes. Este artigo revisa a literatura acerca do sono normal e do sono na UTI. Também analisa seus métodos de avaliação, as causas da má qualidade do sono, suas potenciais implicações no processo de recuperação de pacientes críticos e estratégias para sua promoção.

Left ventricular diastolic dysfunction in obstructive sleep apnoea syndrome by an echocardiographic standardized approach: An observational study.

BACKGROUND: The association between obstructive sleep apnoea syndrome (OSAS), left ventricular (LV) diastolic dysfunction and LV geometry remains controversial because of coexisting disorders. AIMS: To evaluate LV diastolic dysfunction and its independent predictors in a real-life cohort of OSAS patients, by a standardized approach. METHODS: We consecutively included 188 OSAS patients after an overnight polysomnography to undergo clinical evaluation, ambulatory blood pressure measurement and complete echocardiography, combining M-mode, two-dimensional Doppler and tissue Doppler imaging modes. Correlations between OSAS severity and clinical and echocardiographical variables were assessed, and logistic regression models were used to identify possible determining factors of LV diastolic dysfunction. RESULTS: Most patients were hypertensive (n=148, 78.7%) and already receiving treatment by continuous positive airway pressure (n=158, 84.5%). The prevalence of LV hypertrophy, defined by LV mass index (LVMi) normalized by height (2.7), was 12.4%, with a significant correlation with hypertension (P=0.004). The apnoea-hypopnoea index was correlated with body mass index (P<0.0001), 24-hour systolic blood pressure (P=0.01) and LVMi normalized by height (2.7) (P=0.03). Diastolic function assessed by a global approach was impaired for 70 patients (37.2%) and none of the OSAS severity variables was a determining factor after multivariable analysis with adjustment for age and sex. CONCLUSION: Diastolic dysfunction assessed by a standardized approach is common in OSAS and should be routinely evaluated; it is independently predicted by none of the respiratory severity variables.

Sleep in the intensive care unit.

Poor sleep quality is a consistently reported by patients in the ICU. In such a potentially hostile environment, sleep is extremely fragmented and sleep architecture is unconventional, with a predominance of superficial sleep stages and a limited amount of time spent in the restorative stages. Among the causes of sleep disruption in the ICU are factors intrinsic to the patients and the acute nature of their condition, as well as factors related to the ICU environment and the treatments administered, such as mechanical ventilation and drug therapy. Although the consequences of poor sleep quality for the recovery of ICU patients remain unknown, it seems to influence the immune, metabolic, cardiovascular, respiratory, and neurological systems. There is evidence that multifaceted interventions focused on minimizing nocturnal sleep disruptions improve sleep quality in ICU patients. In this article, we review the literature regarding normal sleep and sleep in the ICU. We also analyze sleep assessment methods; the causes of poor sleep quality and its potential implications for the recovery process of critically ill patients; and strategies for sleep promotion.

Cumulative association of obstructive sleep apnea severity and short sleep duration with the risk for hypertension.

Obstructive sleep apnea (OSA) and short sleep duration are individually associated with an increased risk for hypertension (HTN). The aim of this multicenter cross-sectional study was to test the hypothesis of a cumulative association of OSA severity and short sleep duration with the risk for prevalent HTN. Among 1,499 patients undergoing polysomnography for suspected OSA, 410 (27.3%) previously diagnosed as hypertensive and taking antihypertensive medication were considered as having HTN. Patients with total sleep time (TST) <6 h were considered to be short sleepers. Logistic regression procedures were performed to determine the independent association of HTN with OSA and sleep duration. Considering normal sleepers (TST ≥6 h) without OSA as the reference group, the odds ratio (OR) (95% confidence intervals) for having HTN was 2.51 (1.35-4.68) in normal sleepers with OSA and 4.37 (2.18-8.78) in short sleepers with OSA after adjustment for age, gender, obesity, diabetes, depression, current smoking, use of thyroid hormones, daytime sleepiness, poor sleep complaint, time in bed, sleep architecture and fragmentation, and study site. The risk for HTN appeared to present a cumulative association with OSA severity and short sleep duration (p<0.0001 for linear trend). The higher risk for HTN was observed in short sleepers with severe OSA (AHI ≥30) (OR, 4.29 [2.03-9.07]). In patients investigated for suspected OSA, sleep-disordered breathing severity and short sleep duration have a cumulative association with the risk for prevalent HTN. Further studies are required to determine whether interventions to optimize sleep may contribute to lower BP in patients with OSA.

Insomnia related to sleep apnoea: effect of long-term auto-adjusting positive airway pressure treatment.

Insomnia related to sleep apnoea (IA) is highly prevalent, and its proper treatment is still debated. The aim of this study was to test the hypothesis that long-term auto-adjusting positive airway pressure (APAP) treatment improves IA symptoms. 80 patients (mean±sd age 54.9±10.6 yrs, respiratory disturbance index (RDI) 45.0±24.6 events·h(-1)) receiving APAP treatment were followed prospectively for 24 months. Somnolence and depression were assessed at baseline (T0) with the Epworth and the QD2A scales, respectively. Nightly APAP use was measured after 24 months of treatment (T24). The assessment of insomnia at T0 and T24 used the insomnia severity index (ISI). The combination of ISIT0 ≥15 and ISIT0-ISIT24 ≥9 defined the APAP-responding insomnia (APAP-RI) group. A logistic regression analysis identified the factors independently associated with the APAP-RI group. The ISI (13.7±5.7 versus 8.2±6.3) decreased significantly from T0 to T24 (p = 0.0001) for the patients as a whole, with a mean decrease of 13.5±2.9. Among the 39 insomniac subjects (T0), 20 belonged to the APAP-RI group (51%). The Epworth score (OR 1.536, 95% CI 1.093-2.159; p = 0.01) and the RDI (OR 1.080, 95% CI 1.010-1.154; p = 0.02) increased the risk of belonging to the APAP-RI group. IA symptoms improved with APAP treatment, and improvement was associated with the initial severity of the disease and somnolence in our population.

Symptoms of sleep apnea syndrome: high prevalence and underdiagnosis in the French population.

OBJECTIVE: To determine the prevalence of symptoms evocative of obstructive sleep apnea (SE-OSA) and the magnitude of obstructive sleep apnea (OSA) underdiagnosis. METHODS: We used data from a cross-sectional survey conducted in 2008 in a representative sample of the French general population. Data were collected through interviews and self-administrated questionnaires and were complete for 12,203 adults (≥16 years old). SE-OSA was defined by snoring almost every night plus witnessed apneas or excessive daytime sleepiness (Epworth sleepiness scale score>10). RESULTS: The prevalence of SE-OSA was 4.9% (95% CI: 4.5-5.3), and that of self-reported OSA diagnosis was 2.4% (2.1-2.7). The prevalence of SE-OSA was 8% among people with hypertension and 11% among obese people. A previous sleep monitoring session was reported by 2.7% (2.4-3.0) of the participants and by 15.1% of people with SE-OSA. This latter proportion increased with age (24% in people with SE-OSA aged 60 years or over) and was higher in obese people (26%) and in those with chronic diseases (27% among people with hypertension). CONCLUSION: The prevalence of SE-OSA is high in France and OSA remains underdiagnosed, even in people with obesity or hypertension. Further efforts are needed to improve the diagnosis of OSA.

Insomnia symptoms and CPAP compliance in OSAS patients: A descriptive study using Data Mining methods.

BACKGROUND: Obstructive Sleep Apnoea Syndrome (OSAS) and insomnia are common pathologies sharing a high comorbidity. CPAP is a cumbersome treatment. Yet, CPAP compliance must remain optimal in order to reverse excessive daytime sleepiness and prevent the cardiovascular consequences of OSAS. But chronic insomnia could negatively affect CPAP compliance. OBJECTIVE: To assess the consequences of insomnia symptoms on long-term CPAP use. METHODS: A prospective study was conducted on 148 OSAS patients (RDI=39.0+/-21.3/h), age=54.8+/-11.8years, BMI=29.1+/-6.3kg/m(2), Epworth Score=12.2+/-5.4, on CPAP. Using the Insomnia Severity Index (ISI) as an indicator of insomnia (ISI14=moderate to severe insomnia) and baseline data (anthropometric data, sleeping medication intakes, CPAP compliance, Epworth, Pittsburgh Sleep Quality and ISI scores, polygraphic recording data), Data Mining analysis identified the major rules explaining the features "High" or "Low ISI" and "High" or "Low Use" in the groups defined, according to the median values of the ISI and the 6th month-compliance, respectively. RESULTS: Median ISI was 15 and median 6th month-compliance was 4.38h/night. Moderate to severe insomnia complaint was found in 50% of patients. In the "High" and "Low ISI," the 6th month-compliance was not significantly different (3.7+/-2.3 vs 4.2+/-2.3h/night). In the classification models of compliance, the ISI was not a predictor of CPAP rejection or of long-term use, the predictor for explaining CPAP abandonment being the RDI, and the predictor of the 6th month-compliance being the one month-compliance. CONCLUSION: Insomnia symptoms were highly prevalent in OSAS patients, but had no impact on CPAP rejection or on long-term compliance.

Is the aortic root dilated in obstructive sleep apnoea syndrome?

BACKGROUND: Obstructive sleep apnoea syndrome (OSAS) is associated with an increased risk of arterial hypertension (AH), coronary artery disease, atrial arrhythmias, heart failure, stroke and death. Whether OSAS influences aortic root size has not been fully investigated. The aim of our study was to investigate aortic root diameter and aortic stiffness in OSAS. METHODS: Using transthoracic Doppler echocardiography, we evaluated 76 patients with OSAS (mean age 52.7 +/- 9.5 years, 70 men [92%]) with no overt cardiovascular disease. The following parameters were measured offline: aortic diameter at Valsalva sinuses, aortic regurgitation (AR) grade, left ventricular (LV) mass, LV ejection fraction (LVEF, Simpson rule), systolic pulmonary artery pressure (sPAP). Aortic stiffness (carotid-femoral pulse wave velocity, PWV) was measured non-invasively using SphygmoCor technology. RESULTS: Mean duration of OSAS was four years and 84% of patients were being treated with continuous positive airway pressure. AH was documented in 39 (51%) patients. The mean aortic root diameter was 35.3 +/- 3.8 mm (26.9-44.6 mm) and the prevalence of aortic root dilatation was 3.9% (3 of 76 patients). On univariate analysis, age and sex were significant predictors of aortic root dilatation whereas arterial hypertension was not. CONCLUSIONS: The prevalence of aortic root enlargement was not increased in OSAS. Only age and sex and not arterial hypertension, were associated with aortic dilatation.

Residual subjective daytime sleepiness under CPAP treatment in initially somnolent apnea patients: a pilot study using data mining methods.

BACKGROUND AND PURPOSE: Despite correct treatment with positive airway pressure (PAP), obstructive sleep apnea (OSA) patients sometimes remain subjectively somnolent. The reliability of the Epworth Sleepiness Scale (ESS) has been established for healthy subjects and patients under stable conditions; the ESS may eventually vary among treated OSA patients, biasing the results of a cross-sectional analysis of persisting sleepiness. The objective of this study was to depict the evolution of subjective vigilance under treatment using an index of ESS variability (DeltaESS). METHODS: In 80 OSA patients (apnea-hypopnea index [AHI]=54+/-26/h), initially somnolent (ESS=15+/-3) and treated with auto-titrating PAP (APAP) (oxyhaemoglobin desaturation index 3% [ODIapap]=3.4+/-2.2/h; daily APAP use=5.3+/-1.5 h) during 434+/-73 days, ESS scores were regularly collected four times every 109+/-36 days. DESS was calculated and data mining methods (Segmentation and Decision Tree) were used to determine homogeneous groups according to the evolution of ESS scores. RESULTS: When assessed cross-sectionally, 14-25% of the subjects were recognized as somnolent, depending on the moment when ESS was administered. Using data mining methods, three groups were clearly identifiable: two without residual somnolence - group 1, n=38 (47%), with high DeltaESS=-2.9+/-0.8, baseline ESS=16.3+/-3.3, AHI=58.5+/-26.1/h, mean ESSapap=5.1+/-2.4 and group 2, n=31 (39%), with low DeltaESS=-1.1+/-0.5, baseline ESS=13.2+/-1.4, AHI=53+/-27.3/h, mean ESSapap=8.8+/-1.9; and one with persisting sleepiness; group 3, n=11 (14%), with low DeltaESS=-0.3+/-0.8, baseline ESS=16.3+/-3, AHI=38.7+/-10.8/h, mean ESSapap=14.1+/-1.9. Compliance to PAP was high and comparable in the three groups. Age and body mass index (BMI) did not differ. CONCLUSION: Data mining methods helped to identify 14% of subjects with persisting sleepiness. Validation needs to be done on a larger population in order to determine predictive rules.