Treatment of Patients with Co-morbid Insomnia and Obstructive Sleep Apnea

Author: Alexander Sweetman

  • Thesis download: available for open access on 27 Sep 2020.

Sweetman, Alexander, 2018 Treatment of Patients with Co-morbid Insomnia and Obstructive Sleep Apnea, Flinders University, College of Education, Psychology and Social Work

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Insomnia and Obstructive Sleep Apnea (OSA) are the two most common sleep disorders, occurring in 6-10%, and 23-50% of the general population, respectively (1-3). Furthermore, insomnia and OSA frequently co-occur within the same patient, resulting in increased impairments to sleep, daytime functioning, and quality of life (4, 5). Although Co-Morbid Insomnia and Sleep Apnea (COMISA) is a highly prevalent, and debilitating condition, only a small amount of research has investigated treatment approaches in this population.

Research examining treatment approaches in COMISA indicates that these patients are more difficult to treat, compared to patients with either insomnia- or OSA-alone (4). For example, COMISA patients show reduced acceptance and use of Continuous Positive Airway Pressure (CPAP) therapy, compared to patients with OSA-alone (6, 7). Alternatively, sedative and hypnotic medications commonly prescribed for insomnia symptoms can exacerbate manifestations of OSA, through depressant effects on the upper airway and controls of ventilation (4). Finally, Cognitive and Behavioral Therapy for Insomnia (CBT-i) is an effective treatment for primary, and co-occurring insomnia (8, 9), however has received little research attention in the COMISA population.

The current thesis aims to contribute to this field of sleep medicine, by investigating the characteristics, prevalence, and effectiveness of various discrete and combined treatment approaches in the COMISA population. Chapter 1 provides an overview of OSA and insomnia, where they occur independently. Chapter 2 includes a published review article documenting the characteristics, prevalence, and previous treatment attempts in COMISA patients (4). Chapter 3 includes an accepted manuscript, comparing the effectiveness of CBT-i in patients with insomnia-alone, and COMISA. It was found that patients with insomnia-alone (n = 314), and COMISA (n = 141) each experienced large improvements in sleep parameters and daytime impairments during CBT-i. Furthermore, there were no significant differences in improvements between groups, indicating that the effectiveness of CBT-i is not reduced in patients with co-occurring OSA. Chapter 4 includes a manuscript describing a randomized controlled trial investigating the acute effectiveness of CBT-i (n = 72), versus a control condition (n = 73), in treating insomnia symptoms in participants with COMISA. It was found that CBT-i resulted in significantly greater improvements in sleep parameters, and global insomnia severity compared to the control condition. Chapter 5 includes a manuscript examining changes in daytime sleepiness, and subjective sleep parameters, before, during, and after CBT-i, in COMISA patients. This chapter indicated that CBT-i resulted in only a small transient increase in daytime sleepiness, and slight reduction of total sleep time during the first week of treatment, that rebounded to pre-treatment levels during each subsequent week. Chapter 6 reports a randomized controlled trial, investigating the impact of initial treatment with CBT-i (vs. no insomnia-treatment control), on subsequent acceptance and adherence to CPAP therapy, and long-term improvements in insomnia and OSA outcomes. It was found that initial treatment with CBT-i resulted in increased immediate acceptance and long-term use of CPAP therapy, compared to treatment with CPAP-alone. Furthermore, participants in the CBT-i condition reported greater improvements in global insomnia severity, and dysfunctional sleep-related cognitions, over the course of treatment. Finally, Chapter 7 includes an integrated discussion of the implications of the preceding chapters.


1. Ohayon M.M. Epidemiology of insomnia: What we know and what we still need to learn. Sleep Med Rev, 2002. 6(2): p. 97-111.

2. Ohayon MM, Reynolds CF., Epidemiological and clinical relevance of insomnia diagnosis algorithms according to the DSM-IV and the International Classification of Sleep Disorders (ICSD). Sleep Med, 2009. 10.

3. Heinzer R, Vat S, Marques-Vidal P, Marti-Soler H, Andries D, Tobback N, et al. Prevalence of sleep-disordered breathing in the general population: The HypnoLaus study. Lancet Respir Med. 2015; 3(4): 310-8.

4. Sweetman A, Lack LC, Catcheside PG, Antic NA, Chai-Coetzer CL, Smith SS, et al. Developing a successful treatment for co-morbid insomnia and sleep apnoea. Sleep Med Rev, 2017; 33: p. 28-38.

5. Lang CJ, Appleton, SL, Vakulin A, McEvoy RD, Wittert GA, Martin SA, et al. Co‐morbid OSA and insomnia increases depression prevalence and severity in men. Respirology, 2017.

6. Wickwire EM, Smith MT, Birnbaum S, Collop NA. Sleep maintenance insomnia complaints predict poor CPAP adherence: A clinical case series. Sleep Med, 2010. 11(8): 772-6.

7. Suraiya S, Lavie P. Sleep onset insomnia in sleep apnea patients: influence on acceptance of nCPAP treatment. Sleep Med, 2006. 7(Suppl): S85.

8. Morin CM, Culbert JP, Schwartz SM. Nonpharmacological interventions for insomnia: A meta-analysis of treatment efficacy. Am J Psychiatry, 1994; 151(1172-1180).

9. van Straten A, van der Zweerde T, Kleiboer A, Cuijpers P, Morin CM, Lancee J. Cognitive and behavioral therapies in the treatment of insomnia: a meta-analysis. Sleep Med Rev, 2017.

Keywords: insomnia, co-morbid insomnia, cognitive and behavioral therapy for insomnia, obstructive sleep apnea, CPAP, continuous positive airway pressure, OSA, CBT-i, CBTi, COMISA, Sleep Medicine

Subject: Psychology thesis

Thesis type: Doctor of Philosophy
Completed: 2018
School: College of Education, Psychology and Social Work
Supervisor: Professor Leon Lack