Editor's Note: Commentary based on Chai-Coetzer CL, Luo YM, Antic NA, et al. Predictors of Long-Term Adherence to Continuous Positive Airway Pressure Therapy in Patients with Obstructive Sleep Apnea and Cardiovascular Disease in the SAVE Study. Sleep 2013;36:1929-37.

Study Objective

To determine the clinical variables that best predict long- term continuous positive airway pressure (CPAP) adherence among patients with cardiovascular disease who have obstructive sleep apnea (OSA).

Design

12-mo prospective within-trial observational study.

Setting

Centers in China, Australia, and New Zealand participating in the Sleep Apnea cardioVascular Endpoints (SAVE) study.

Patients

There were 275 patients age 45-70 y with cardiovascular disease (i.e., previously documented transient ischemic attack, stroke, or coronary artery disease) and OSA (4% oxygen desaturation index (ODI) > 12) who were randomized into the CPAP arm of the SAVE trial prior to July 1, 2010.

METHODS: Age, sex, country of residence, type of cardiovascular disease, baseline ODI, severity of sleepiness, and Hospital Anxiety and Depression Scale (HADS) scores plus CPAP side effects and adherence at 1 mo were entered in univariate analyses in an attempt to identify factors predictive of CPAP adherence at 12 mo. Variables with P < 0.2 were then included in a multivariate analysis using a linear mixed model with sites as a random effect and 12-mo CPAP use as the dependent outcome variable.

Measurements and Results

CPAP adherence at one, six, and 12 mo was (mean ± standard deviation) 4.4 ± 2.0, 3.8 ± 2.3, and 3.3 ± 2.4 h/night, respectively. CPAP use at 1 mo (effect estimate ± standard error, 0.65 ± 0.07 per h increase, P < 0.001) and side effects at 1 mo (-0.24 ± 0.092 per additional side effect, P = 0.009) were the only independent predictors of 12- mo CPAP adherence.

Conclusion

Continuous positive airway pressure use in patients with coexisting cardiovascular disease and moderate to severe obstructive sleep apnea decreases significantly over 12 months. This decline can be predicted by early patient experiences with continuous positive airway pressure (i.e., adherence and side effects at one month), raising the possibility that intensive early interventions could improve long-term continuous positive airway pressure compliance in this patient population.

Commentary/Perspective

Continuous positive airway pressure (CPAP) is the treatment of choice for symptomatic moderate to severe obstructive sleep apnea (OSA). CPAP therapy improves symptoms of excessive daytime sleepiness and reduces the risk of motor vehicle crashes.¹ Epidemiological evidence also indicates that CPAP lowers blood pressure,² improves left ventricular systolic function and heart failure symptoms,³ and decreases cardiac arrhythmias in OSA patients.⁴ However, CPAP is often times not well tolerated by patients with OSA, and the long-term adherence to CPAP is in general low.⁵

The present results from the Sleep Apnea cardioVascular Endpoints (SAVE) study ⁶ mirror the findings of Sawyer et al., who observed that adherence to CPAP is at least in part dependent on the patient's support environment and early experiences with CPAP use.⁷ Similarly, Broström et al. conducted a qualitative study on CPAP adherence consisting of in-depth interviews with 23 patients with OSA.⁸ This study identified negative psychological effects of the equipment and negative attitudes to CPAP treatment as putative barriers to treatment adherence.⁸ Furthermore, a community-based study suggested that adherence to CPAP may be related to attitudes and beliefs about OSA and CPAP, particularly among ethnic minorities.⁹ A limitation to the generalization of the SAVE study relates to the fact that the participants in this study were mainly from China, with a smaller number of participants from Australia and New Zealand. It may be difficult to generalize their findings to other cultural or ethnic groups.

In summary, available evidence including the present findings of SAVE study suggest that the barriers to the adoption and potential adherence to CPAP in patients with OSA and cardiovascular disease include patients' concerns and early negative experiences with CPAP use. Treatment of symptomatic OSA with CPAP should include thorough education and strategies to overcome early negative experiences with CPAP use.

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References

1. George CF. Reduction in motor vehicle collisions following treatment of sleep apnoea with nasal CPAP. Thorax 2001;56:508-12.
2. Logan AG, Tkacova R, Perlikowski SM, Leung RS et al. Refractory hypertension and sleep apnoea: effect of CPAP on blood pressure and baroreflex. Eur Respir J 2003;21:241–7.
3. Bradley TD, Logan AG, Kimoff RJ, Sériès F et al. Continuous positive airway pressure for central sleep apnea and heart failure. N Engl J Med 2005;353:2025–33.
4. Javaheri S. Effects of continuous positive airway pressure on sleep apnea and ventricular irritability in patients with heart failure. Circulation 2000;101:392–7.
5. Joo M, Herdegen J. Sleep apnea in an urban public hospital: assessment of severity and treatment adherence. J Clin Sleep Med 2007;3:285–288.
6. Chai-Coetzer CL, Luo YM, Antic NA, Zhang XL et al. Predictors of long-term adherence to continuous positive airway pressure therapy in patients with obstructive sleep apnea and cardiovascular disease in the SAVE study. Sleep 2013;36:1929-37.
7. Sawyer S, Deatrick J, Kuna ST, Weaver TE. Differences in Perceptions of the Diagnosis and Treatment of Obstructive Sleep Apnea and Continuous Positive Airway Pressure Therapy among Adherers and Nonadherers. Qual Health Res 2010;20:873–892.
8. Broström A, Nilsen P, Johansson P, Ulander M et al. Putative facilitators and barriers for adherence to CPAP treatment in patients with Obstructive sleep apnea syndrome: a qualitative content analysis. Sleep Med 2010;11:126–130.
9. Shaw R, McKenzie S, Taylor T, Olafiranye O et al. Beliefs and attitudes toward obstructive sleep apnea evaluation and treatment among blacks. J Natl Med Assoc 2012;104:510-9.

Keywords: Cardiovascular Diseases, Cardiovascular System, Sleep Apnea, Obstructive, Continuous Positive Airway Pressure, Early Intervention, Educational, Patient Compliance

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