Treatment adherence and outcomes in flexible vs standard continuous positive airway pressure therapy

Abstract

Study objectives: To compare adherence and clinical outcomes between flexible positive airway pressure (PAP) [C-Flex; Respironics; Murraysville, PA] and standard PAP therapy (ie, continuous positive airway pressure [CPAP]).

Design and setting: A controlled clinical trial of CPAP therapy vs therapy using the C-Flex device in participants with moderate-to-severe obstructive sleep apnea. Participants were recruited from and followed up through an academic sleep disorders center.

Participants: Eighty-nine participants were recruited into the study after they had undergone complete in-laboratory polysomnography and before initiating therapy. Participants received either therapy with CPAP (n = 41) or with the C-Flex device (n = 48), depending on the available treatment at the time of recruitment, with those recruited earlier receiving CPAP therapy and those recruited later receiving therapy with the C-Flex device. Follow-up assessments were conducted at 3 months.

Measurements and results: The groups were similar demographically. The mean (+/- SD) treatment adherence over the 3-month follow-up period was higher in the C-Flex group compared to the CPAP group (weeks 2 to 4, 4.2 +/- 2.4 vs 3.5 +/- 2.8, respectively; weeks 9 to 12, 4.8 +/- 2.4 vs 3.1 +/- 2.8, respectively). Clinical outcomes and attitudes toward treatment (self-efficacy) were also measured. Change in subjective sleepiness and functional outcomes associated with sleep did not improve more in one group over the other. Self-efficacy showed a trend toward being higher at the follow-up in those patients who had been treated with the C-Flex device compared to CPAP treatment.

Conclusions: Therapy with the C-Flex device may improve overall adherence over 3 months compared to standard therapy with CPAP. Clinical outcomes do not improve consistently, but C-Flex users may be more confident about their ability to adhere to treatment. Randomized clinical trials are needed to replicate these findings.

FIGURE 1

Raw data from one patient receiving conventional CPAP therapy at 6 cm H₂O (top) and therapy using the C-Flex technology (bottom). I = inspiration; E = expiration; Thermistor Flow = oronasal thermistor; Thoracic Effort = qualitative signal obtained from a piezobelt; Pressure Mask = mask pressure obtained using standard pressure transducer (qualitative signal). Note the drop in mask pressure during expiration during therapy using the C-Flex technology compared to that with conventional CPAP therapy.

Figure 2

Average nightly use over time by group. Error bars = SEM.