Factors associated with the diagnosis and treatment of obstructive sleep apnoea in chronic heart failure: a mixed methods study
Authors: Bernhardt L , Robertson N , Squire I 
Published: July 2023

Abstract

Funding Acknowledgements
Type of funding sources: Other. Main funding source(s): This study was co-funded by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care East Midlands (CLAHRC EM), now recommissioned as NIHR Applied Research Collaboration East Midlands (ARC EM) and Leicestershire Partnership NHS Trust - Raising Health Charitable Funds Award and supported by the NIHR Leicester Biomedical Research Centre. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Background
Heart Failure (HF) is associated with a considerable burden of disability that includes frequent hospitalisation and high risk of mortality. Despite advances in HF treatment, many patients continue to experience symptoms and will die from progressive HF, often exacerbated by the presence of co-morbidities, such as obstructive sleep apnea (OSA). Despite the high prevalence of OSA in chronic HF and the association with the development and progression of chronic HF, OSA remains largely under diagnosed and under treated.

Purpose
To explore factors associated with the diagnosis and treatment of OSA in CHF.

Methods
A convergent parallel mixed methods research design was utilised. Quantitative methods included a systematic review and meta-analysis, diagnostic validation study and a survey study, whilst semi-structured interviews and reflexive thematic analysis was utilised for the qualitative component. Data collection and data analysis were conducted simultaneously with the integration of the findings in the discussion.

Results
The systematic review and meta-analysis showed that the STOP-Bang screening questionnaire had a high sensitivity to detect OSA in the sleep clinic and surgical populations but lacked adequate specificity. The diagnostic validation study indicated a high sensitivity of the STOP-Bang questionnaire, but due to differences in prevalence, risk of selection bias and spectrum effect, validation in a sleep clinic population is unlikely to reflect the true performance of the STOP-Bang questionnaire in a stable CHF population. The survey study demonstrated a knowledge deficit in the diagnosis and treatment of OSA, and variable practice among HF clinicians in the UK. Findings from the qualitative component identified several key barriers and enablers across the OSA diagnostic pathway from both patients’ and clinicians’ accounts.

Conclusion
Due to a lack of typical OSA symptoms, there is currently no real evidence of cardiovascular hospitalisation and mortality benefit for OSA treatment in CHF. This contributed to a paucity of guidance on the management of OSA in CHF clinical guidelines. Due to a lack of typical OSA symptoms, screening questionnaires that rely on patient symptoms may be less effective. Although clinicians felt that OSA was an important clinical condition, findings demonstrated a disconnect between the stated level of clinical importance and clinicians’ actual level of knowledge. The current absence of evidence to support the treatment of OSA in CHF and paucity of CHF guidelines to inform the management of OSA in CHF, are likely to contribute to clinicians not prioritising the recognition and treatment of OSA in CHF.