Effectiveness of remote monitoring in improving CPAP compliance and the impact of preexisting organisation of standard care: a randomised controlled trial

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder. OSA can be characterised by partial or complete inspiratory upper airway collapse during sleep, resulting in periodic oxygen desaturation and disruption of sleep [1, 2]. When these events occur frequently, they can result in daytime symptoms such as excessive sleepiness, impaired cognition and memory, mood alterations, and impediment in daily functioning. Patients with untreated OSA are at increased risk for cardiovascular and metabolic complications [3‐8].

Continuous positive airway pressure (CPAP) is the treatment of choice for severe OSA, with adherence of 60-70% [9, 10]. Because short-term adherence and early perceived benefits are the best predictors of long-term adherence, efforts to optimise adherence are best done before or shortly after starting treatment [10‐14]. Intensive support has proven before to be beneficial [15‐17].

Telemedicine can be of use in multiple ways [18]. Telemonitoring is enabling clinicians to continuously monitor specific parameters of treatment efficacy, thereby permitting prompt and timely adjustments to therapy if indicated. This was originally done by interactive patient-controlled communication by telephone combined with positive re-enforcement and later by remote monitoring [12, 19]. The primary outcome of our study was to investigate the effect of telemonitoring on mean hours/night of CPAP use after 10 weeks of treatment.

We performed a single-blind, single-centre, randomised, controlled trial of telemonitoring added to standard care versus standard care alone in patients with severe OSA (AHI ≥30). Patients were randomised to the telemonitoring or standard care group in a 1:1 ratio through blinded allocation using an envelope-procedure. The study was approved by a Research Ethics Board of the Maxima Medisch Centrum (NL 52339.015.15).

During the study period, a total of 288 patients was screened for inclusion. A total of 230 patients who were willing and eligible to participate were enrolled in the study with balanced baseline characteristics (fig. 2).

Table 1 shows the patient characteristics. There were no significant differences in age, BMI, AHI, ESS or FSS between the two study groups.

Compliance with CPAP after 10 weeks was similar in both groups. During the last week of this period, patients in the telemonitoring arm used CPAP for a mean of 6:27 hr/day versus 6:35 hr/day in the standard care arm (mean difference = 8 min, p = 0.57) (Table 2). Other outcomes of therapy were comparable as well: AHI (2.4; 2.4/hr, p = 0.89), ESS (5.8; 4.9, p = 0.22), FSS (28.2; 28.7, p = 0.80). The number of contacts of each patient with a healthcare professional was significantly higher during the follow-up from week 3 until week 10 in the telemonitoring group (0.25; 0.13, p = 0.03). The number of patients who could be evaluated after 1 year was equally distributed (104 vs 104, p=1.00), as were compliance in mean hours of CPAP use (6:43; 6:49 hr, p=0.59) and residual AHI (1.9; 2.2/hr, p=0.41).

In univariate analyses, there were no significant predictors of CPAP adherence or discontinuation of CPAP (ESS, age).

Remote monitoring of CPAP therapy did not have any additional effect on compliance in our population of CPAP- naïve patients with symptomatic severe OSA in the setting of a patient-counselling system with high adherence to CPAP, which implies a ceiling effect for improving CPAP compliance (90%, 6:46 hours/night after 1 year). This high compliance may be due to a high complaint burden (ESS) and the standard intensive follow-up and support already used in the control group, which also showed good compliance. This is in line with other studies and a recent meta-analysis, which confirmed that telemonitoring was helpful when basal compliance is lower (60-70%) in the control group [18, 22, 23]. Our study is the first one performed in the Netherlands that investigated the effectiveness of remote monitoring in improving CPAP compliance in patients with symptomatic severe OSA. The results from earlier studies in a Canadian and American population cannot be generalised to our Dutch population, especially when a high adherence is expected in the general sleep-apnea population [24, 25].

The interventions in our study were mainly focussed on improving compliance and reducing the side effects of CPAP therapy, using telemonitoring data to guide and adjust the therapy if needed in an early stage. Interventions were predominantly performed during the first 3 weeks. Our study mainly carried out interventions during the first 10 weeks of treatment. Other studies have shown that interventions which were implemented in an early stage had the greatest effect on compliance [26]. It was not clear when interventions are necessary in patients with a high degree of compliance.

Our protocol for interventions used lower thresholds for intervention compared to other studies. Our minimum for compliance was 5 hr/night instead of 3 or 4 hours and mask leakage under 24 l/min instead of 27-50 l/min [18, 27, 28].

Dropouts occurred mainly in the first 3 months of treatment, primarily because of CPAP intolerance, and were equally distributed over both groups. Dropouts after 3 months were mainly due to other reasons, for example resolved OSA (weight loss), OSA-unrelated death (2), metastatic malignancy or change to a mandibular advancement device (MAD).

Turino et al. had similar results to ours using a control reference group with a lower compliance of 4.9 hr/night when compared to our study, but with a lower burden of complaints at baseline [28]. Antallainen et al. reported a comparable adherence level in both groups compared to our study, with a lower level of complaints at baseline but probably a more intense follow-up during the first 4 weeks [AHI 34.6/hr, ESS 8.2]. In their study, adjustments were performed by a nurse by phone or visit to the outpatient ward and not by a web-based approach or by making use of other multimedia, as was done in most other studies. In addition, Antallainen et al. only randomised patients after the titration period, which was done as well by Sparrow et al. [16, 24]. The latter authors suggested that they may have lost patients who had a negative titration experience, or may have had a bias in the enrolment of patients who anticipated they needed help with adherence to CPAP. Our results showed that telemonitoring can be used directly from the initiation of PAP therapy, and dropouts due to intolerance in a highly compliant group could not be influenced by this telemonitoring approach.

Studies with patient groups with low compliance (mean ≤ 3.2 hr/night) such as Sparrow et al. and Fox et al. (self- reported compliance by automated telephone linked motivational enhancement or telemonitoring to interventions by the nurse) showed that an intervention resulted in a clinically and significantly improved CPAP adherence in both their control and telemonitored patient group compared to our study [16, 27]. Criteria for sufficient use are defined as 4 hours of use per night on 70% of days [29]. However, the complaint burden was lower in the study of Fox et al. (ESS before treatment: 9.9 vs 9.7 for remote monitoring vs control) [27].

Bruyneel et al. suggested that guidance by medical staff is more effective in optimising compliance than intervention generated by automated feedback systems for both the telemonitoring and the control group [15]. The limitations in previous studies are the relatively modest number of patients included and the lack of using the same type of CPAP device with only the telemonitoring option switched off in the control group [27]. This implies that the patients’ perception of monitoring might have increased their adherence. They might have felt more responsible and more motivated not to disappoint their healthcare providers. In our study, both groups used the same CPAP device, with the telemonitoring function switched off in the control group.

Our study emphasises the effect of telemonitoring of APAP parameters (such as compliance, air leakage and AHI) on compliance during the first weeks after starting treatment in a Dutch population, as well as the effect of early intervention on continuing the therapy after 10 weeks up to 1 year follow-up. As previously mentioned, the first weeks of treatment are crucial for adherence. Remote monitoring can be helpful during the initial CPAP titration, for example to detect problems earlier, and could reduce the need for outpatient contacts, but there is insufficient evidence that the total number of contacts can be reduced without sacrificing compliance. Remote monitoring may simplify and improve telemedicine, especially for patients who have to travel a long distance to the hospital, and may replace physical appointments or may complement an E-health consultation [24]. Implementation of this type of system could result in substantially improved care in patients with OSA, but this requires the availability of wireless options and internet, depending on the type of remote-monitoring system. Effective therapy with good adherence mostly depends on the patient’s motivation, supplemented with a solid foundation of a well-functioning outpatient clinic providing personal support for the patient with human interaction. Implementation of telemonitoring may also lead to greater patient satisfaction and possibly a reduction in staff time and cost. It is essential to regulate telemonitoring contacts according to a standardised protocol to prevent unnecessary contacts with the patient and temper the workload for the sleep professionals. In our clinic this protocol has been effectively implemented in daily practice according to the conditional recommendation of the American Academy of Sleep Medicine guideline [30].

Remote monitoring of CPAP had no additional effect on compliance in our single-centre population of patients with symptomatic severe OSA. This was probably because of the standard intensive follow-up system and support, with high adherence to CPAP as a result (“ceiling effect”). However, telemonitoring might be of benefit in certain patient groups with complex problems at the start of therapy or observed low adherence. These findings must be verified in other centres. The benefits may extend to patients with less mobility or long traveling distances and can replace outpatient consultations by E-health.