Dominique Rakotonanahary

The age and other factors in the evaluation of compliance with nasal continuous positive airway pressure for obstructive sleep apnea syndrome. A Cox's proportional hazard analysis.

Objective: To elucidate the predictive role of age and other pre-treatment, putative confounding factors on compliance with nasal continuous positive airway pressure (nCPAP) therapy.Patients and methods: This study was designed as a prospective cohort study in the setting of a sleep laboratory in a teaching hospital at Saint Antoine, Paris. One hundred and sixty-three patients referred to the sleep laboratory with complaints of snoring and excessive daytime sleepiness for whom nCPAP had been prescribed for obstructive sleep apnea syndrome (OSAS; defined as an apnea-hypopnea index (AHI) of >15/h of sleep during a polysomnographic recording) were followed for a median period of 887 days. The main outcome measure was the risk ratio for elderly patients associated with nCPAP compliance.Results: Four patients, who remained under treatment, died before the end of the study, and 50 patients stopped their nCPAP therapy for reasons other than death (insomnia, equipment too noisy, etc.). When compliance curves were compared by univariate analysis (log-rank test), the oldest group (57/163 patients, >60 years old) was significantly less compliant with nCPAP than the youngest (P=0.01). However, in the Coxs proportional hazards model, age did not exert any independent effect on compliance with nCPAP after controlling for confounding factors (adjusted relative risk, 1.09, 0.5-2; P=0.70). On the other hand, female sex (adjusted relative risk, 2.8, 1.4-5.4; P=0.002), a body mass index (BMI) of </=30 kg/m(2) (adjusted relative risk, 2.2, 1.2-4; P=0.006), an Epworth sleepiness scale (ESS) score of </=15 (adjusted relative risk, 3.2, 1.1-8.9; P=0.025), an AHI of </=30/h (adjusted relative risk, 2.2, 1.2-4; P=0.01) and a nCPAP of >/=12 cmH(2)O (adjusted relative risk, 2.3, 1.2-4.4; P=0.011) were predictive factors for non-compliance.Conclusion: This study suggests that there is no independent effect of age on compliance with nCPAP therapy.

Objective patient compliance in long-term use of nCPAP

Concerns remain regarding patient compliance with nasal continuous positive airway pressure (nCPAP). Poor objective compliance during the first months of treatment has been reported, but no data are available among chronically treated patients. Use of nCPAP, in 17 chronically treated obstructive sleep apnoea patients (820+/-262 days) was evaluated objectively using a pressure monitor (MC+; Sefam, France). Two consecutive recording periods of 30 sessions of treatment were scheduled at the patients home. To minimize the potential bias caused by the introduction of the monitor, only the pressure data obtained at the end of the second period of recording (T2) were analysed. During the 28.1+/-2.6 monitored days, the mean effective daily rate of use was 7.1+/-1.1 h, 97% of the rate indicated by the standard in-built time counter. The prescribed pressure was observed during 95% of the machine run time. The nCPAP system was used for 94% of the monitored days. Sixty percent of the patients used their device every day. These preliminary results suggest that, contrary to reported compliance during the early period of the treatment, objective use of nasal continuous positive airway pressure therapy in chronically treated patients is satisfactory.

Economic studies and 'technical' evaluation of telemedicine: the case of telemonitored polysomnography.

Information and communication technology (ICT) is not yet integrated into current medical practice and frequently, organizational patterns of health care production are held responsible for this situation. However, and quite paradoxically, measures recently taken in France indicate that a preferential role is granted to ICT in order to promote the development of healthcare networks. In this context, one should carefully examine which factors, other than organizational ones, can explain the very slow diffusion of telemedicine. Actually, medical assessment of telemedicine is very seldom and the medical community is unable to appreciate the extent that this technology would modify the quality of care provided. Furthermore, and as a consequence of the former, there is no economic evaluation of telemedicine applications and its effects, in terms of productivity, remain virtual. In this article, based on an early evaluation of telemonitored polysomnography to diagnose sleep apnea syndrome, we show that it is possible, even at an experimental stage, to produce appropriate and convincing clinical results stating the true technological effectiveness (choice of an adequate clinical trial, selection of appropriate endpoints). Specific attention is given to the technical conditions in which the technology is assessed, we also provide most of the data that should be taken into account to foresee the major organizational transformations of the production processes. Our results show that early clinical ad hoc evaluations of telemedicine applications can be conducted promptly, providing strong clinical results and useful data for any forthcoming economic evaluation.

Wrist-actigraphic estimation of sleep time under nCPAP treatment in sleep apnoea patients

The aim of this study was to correlate daily use of nasal continuous positive airway pressure (nCPAP) with total sleep time (TST) evaluated by home actigraphy. Actigraphy was validated by comparing TST determined by actigraphy (aTST) and polysomnography (pTST) in 24 untreated patients with suspected sleep apnoea. The % sleep time spent under nCPAP was estimated on 3 consecutive days in 28 patients receiving long-term nCPAP, by comparing machine-use periods with sleep periods identified by home actigraphy. The mean difference between pTST and aTST was 2.5 min. The correlation coefficient between aTST and pTST was 0.90. Daily use of nCPAP over the 3 study days was 388±114 min. nCPAP was used 41–100% (82±17% (mean±sd)) of sleep time detected by actigraphy. Some patients used nCPAP during nonsleep periods. In conclusion, comparison of nasal continuous positive airway pressure use with sleep time estimated by home actigraphy shows marked individual differences in the % sleep time under nasal continuous positive airway pressure. These results suggest that actigraphic estimation of sleep time under nasal continuous positive airway pressure could provide a better index than simple daily use of the device to evaluate the impact of treatment in sleep apnoea.

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.

Evaluating optisas, a visual method to analyse sleep apnea syndromes

The Sleep apnea syndrome is a real public health problem. Improving its diagnosis using the polysomnography is of huge importance. Optisas was a visual method allowing translating the polysomnographic data into a meaningful image. In a previous paper, it was shown to bring extrainformation in 62% of cases. Here its capacity for displaying information of the same relevance as the one got using the classical report of the polysomnography is studied. The main result is that this capacity is weak and seems to be present only to identify the obstructive sleep apnea syndrome. Moreover this study suggests to improve the standardization of the classical report in the framework of a quality insurance process.