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

Abstract

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.

Monitoring Sleep-Wake Rhythm with Actigraphy in Patients on Continuous Positive Airway Pressure Therapy

“…The difference in TST between PSG and actigraphy exceeded 1 h in 4 patients, with TST being underestimated by actigraphy in 1 case and overestimated in 3 cases, and the difference in sleep efficiency between PSG and actigraphy values exceeded 10% in 4 patients, with sleep efficiency being underestimated by actigraphy in 2 cases and overestimated in 2 cases. In other studies with actigraphy [12,35], as well as our study, actigraphy under- and overestimated TST in some patients. These results might be reflected by poor 2SD on Bland-Altman plots.…”

“…Percent sleep time under CPAP treatment determined by actigraphy could constitute a better index to evaluate the effectiveness of CPAP treatment than simple daily compliance. Actigraphic estimation of the percent sleep time under CPAP could be useful in patients presenting a low clinical benefit, despite an apparently correct daily use of CPAP [12,35]. Therefore, objective assessment tools, e.g.…”

“…In a previous study, the correlation between daily use of CPAP with TST evaluated using home actigraphy was investigated in patients with OSAS [12]. Home actigraphic estimation of sleep time demonstrated that percent sleep time (time in bed) under CPAP was potentially high, but showed remarkable individual differences.…”

“…The advantages of the actigraph – its objectivity, portability and convenience – account for its widespread use in measuring sleep [12,13,14]. Actigraphy consists of an accelerometer and memory storage, both fitted into a watch-like device usually to be worn around the non-dominant wrist.…”

High Altitude Sleep Disturbances Monitored by Actigraphy and Polysomnography

“…Depending on the analysis algorithm applied, the bias and limits of agreement for total sleep time were 18.5 -41.4 min and 8.1 -42.0 min, respectively; the bias and limits of agreement for sleep efficiency were 4 -8% and 2 -9%, respectively. Gagnadoux et al (2004) evaluated actigraphy in patients with obstructive sleep apnea syndrome during a night in the sleep laboratory without CPAP therapy. The bias of actigraphic compared to polysomnographic estimates of total sleep time was nonsignificant (2.5 min), however the precision was poor as reflected in the very wide limit of agreement of -70.6 min.…”