An Exploration of Factors Associated with the Diagnosis and Treatment of Obstructive Sleep Apnoea in Chronic Heart Failure: A mixed methods study

Sleep disordered breathing (SDB) is a comorbidity that is prevalent in chronic heart failure (CHF) and associated with substantial morbidity and mortality. As it is largely under diagnosed and under treated, the overarching aim of this thesis was to explore factors associated with the diagnosis and treatment of OSA in patients with CHF, with a focus on the diagnostic accuracy of existing screening questionnaires, perceived barriers and enablers from CHF patients’ and clinicians’ perspectives, and clinician knowledge, attitudes, and clinical practices.

In the first study, the accuracy and clinical utility of existing OSA screening questionnaires were evaluated and compared. While the STOP-Bang questionnaire had a high sensitivity to detect OSA in both the sleep clinic and surgical cohorts, it lacked specificity. 

In the second study, the diagnostic accuracy of the STOP-Bang questionnaire was evaluated in a sleep clinic cohort with co-existing CHF. Findings indicated a high sensitivity of the STOP-Bang questionnaire to detect OSA in a sleep clinic population with co-existing CHF, however, precision of these findings was limited by a small sample size.

In the third study, qualitative analysis of interviews was utilised to explore perceived barriers to and enablers of the diagnosis and treatment of OSA from CHF patients’ and clinicians’ perspectives. Several barriers and enablers were identified across the OSA diagnostic pathway.

In the fourth study, an online survey evaluated the knowledge, attitudes, and clinical practice of heart failure clinicians. Results demonstrated a knowledge deficit in the diagnosis and treatment of OSA and variable practice among HF clinicians.

This thesis highlights several barriers associated with the diagnosis and treatment of OSA in CHF that could form the foundation of targeted interventions to aid the diagnosis and treatment of OSA in CHF, should the evidence change in the future.