Review, CPAP Adherence, & Follow-up

Follow-up is essential to improve adherence including by education, behavioural therapy, peer support, or telehealth (individual, peer-to-peer, group format), and may be required for CPAP troubleshooting (mask is comfortable, humidification is operational).

The results of all testing for OSA should be reviewed during a face-to-face consultation with the patient. The best possible adherence to therapy is achieved through early patient education and monitoring, especially in the first two to six weeks including telephone calls and as-needed face to face consultations.

CPAP treatment effectiveness is limited by variable adherence; 46 to 83% of patients with OSA have been reported to be nonadherent to treatment, when adherence is defined as greater than 4 hours of nightly use.¹ No single factor has been consistently identified as predictive of adherence. The rate of CPAP adherence remains persistently low over twenty years of reported data (1994 to 2015, 66 studies); CPAP use averages ~4.5 hr per night, but was used on only 38% of nights within the first 6 months of treatment and 34% for 6 months or more. No clinically significant improvement in CPAP adherence was seen even in recent years despite efforts toward behavioural intervention and patient coaching.² It is paramount to implement interventions that can improve adherence, including education, behavioural therapy (motivational interviewing and CBT), peer support, and telehealth delivered to patients in individual, peer-to-peer, or group format, troubleshooting, and telemonitoring interventions.^{3, 4}

Predictors for long term CPAP adherence include good early CPAP adherence (e.g. in the first 1-3 months); snoring history; apnoea hypopnoea index (AHI, particularly ≥30); daytime sleepiness particularly Epworth sleepiness scale (ESS, particularly > 10).⁵ Further predictors of long-term adherence are a patient’s willingness to engage with the therapy and their understanding of their disease and treatment benefits. Thus, it is important to ensure that patients are well educated about the benefits of CPAP therapy in relation to their OSA symptoms, as well as successfully addressing early CPAP side effects. Good adherence may be achieved by ensuring that the mask is comfortable, humidification is operational, there is no anatomic obstruction (e.g. chronic nasal injury, secondary obstruction) requiring surgical intervention. For OSA patients living with domestic partners, the partner will likely be an integral component to any successful CPAP therapy adherence.⁶

Poor mask selection or fit results in mask discomfort, air leaks, skin breakdown and eventually ineffective treatment of OSA ⁷ Common side effects of CPAP include mask discomfort, which can be reduced with proper attention to mask fit, dry mouth (due to mask leaks and/or relatively dry air of CPAP machine), which can be alleviated by addition of a humidification circuit, use of a chin strap and also by using moisturising mouth sprays/gels, and nasal stuffiness/coryza, which usually responds to nasal corticosteroids, humidification, and a chin strap, ear discomfort, which can be alleviated by the use of intranasal corticosteroid spray. Furthermore, mask air leaks can occur around the mask causing eye irritation and may also result in aerophagia, earache, sinus pain, mouth breathing and suboptimal pressure delivery to the upper airway. The patient should be encouraged to also arrange a review with, and discuss their concerns with, the CPAP nurse/ CPAP provider for review of mask fit, adherence issues and CPAP equipment.

Recognition of nonadherence, is important because there are a variety of educational, behavioural and troubleshooting interventions that can help promote CPAP use. Adherence and efficacy can be monitored remotely with CPAP devices that include modems, which allow bidirectional communication so that pressures can be adjusted remotely. Possible causes of treatment failure include nonadherence or suboptimal adherence, weight gain, an inappropriate level of prescribed positive pressure, or an additional disorder causing sleepiness (e.g. narcolepsy) that may require alterations in the therapeutic regimen. Once the patient's therapy has been optimized and symptoms resolved, regular follow-up (at least annually) is needed to assess usage and monitor for recurrent OSA, new side effects, fluctuations in body weight and monitoring of comorbid conditions.⁸

The patient should be educated about the risk factors and consequences of OSA,⁹ including increased risk of motor vehicle and work-related accidents.¹⁰ Accident prevention for patients with moderate or severe OSA who are sleepy during the day is of importance. Objective repeat sleep evaluation is indicated for patients who do not improve or who have recurrent or persistent symptoms such as daytime sleepiness ⁹ Commercial drivers with OSA should be reviewed annually including measures of therapy adherence.

Patients should be counselled that they should always inform their medical providers that they have OSA, especially if they are to have surgery or start new medications (medications with inhibitory effects on the central nervous system, antidepressants that cause weight gain (e.g. mirtazapine), restless legs syndrome or periodic limb movements, and those that may worsen daytime sleepiness, including benzodiazepines, benzodiazepine receptor agonists, barbiturates, other antiepileptic drugs, sedating antidepressants, antihistamines, and opiates, should be avoided if reasonable alternatives exist).¹¹