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Volume 14 No. 10
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Accepted Papers

Scientific Investigations

Defining the Core Components of a Clinical Review of People Using Continuous Positive Airway Pressure Therapy to Treat Obstructive Sleep Apnea: An International e-Delphi Study

Phyllis Murphie, RGN, MSc1,2; Stuart Little, MD1; Robin Paton, BN1; Brian McKinstry, MD, PhD3; Hilary Pinnock, MD, PhD2
1Allergy and Respiratory Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, United Kingdom; 2Department of Respiratory Medicine, NHS Dumfries and Galloway, United Kingdom; 3e-Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, United Kingdom


Study Objectives:

Guidelines recommend regular review of individuals using continuous positive airway pressure (CPAP) to treat obstructive sleep apnea but do not agree on the core components and frequency. We aimed to achieve consensus on essential components and frequency of review.


We used an e-Delphi approach, recruiting a multidisciplinary international expert panel to identify components based on a list compiled from guidelines and to score these on a scale 1 to 5 over three rounds. Consensus was defined as ≥ 75% agreement for scores of 4 or higher. Free-text comments were thematically analyzed.


Forty participants completed 3 rounds scoring 36 potential components. Seventeen components achieved consensus: treatment acceptability, sleep quality, symptom resolution (including reduction in apnea-hypopnea index), assessment of sleepiness (including when driving), technical CPAP issues (mask fit/humidification/cleaning/filters), recording CPAP adherence, and quality of life. Participants suggested 12 to 18 monthly reviews (more frequent when commencing CPAP) or “on demand.” Free-text comments highlighted that reviews should be multidisciplinary, flexible (including telehealth), and focus on symptom control.


We mapped 17 prioritized components to a suggested template that may support clinical reviews. Reviews should be flexible, frequently in the early stages of commencing CPAP, shifting to “on demand” and/or remote follow-up for maintenance. Our findings may inform future guideline recommendations for reviewing CPAP users.


Murphie P, Little S, Paton R, McKinstry B, Pinnock H. Defining the core components of a clinical review of people using continuous positive airway pressure therapy to treat obstructive sleep apnea: an international e-Delphi study. J Clin Sleep Med. 2018;14(10):1679–1687.


Current Knowledge/Study Rationale: Current sleep medicine guidelines recommend regular review in individuals using continuous positive airway pressure (CPAP) and who have obstructive sleep apnea. However, they do not collectively define the core components and frequency of such a review. We aimed to achieve consensus on essential components and frequency of review.

Study Impact: This is the first study to provide an international consensus on the most important components that may be considered when reviewing people using CPAP therapy. Our findings may inform future guideline recommendations for reviewing individuals using CPAP.


Obstructive sleep apnea (OSA) is a common, treatable condition that represents a major public health issue globally and is an important cause of morbidity and mortality.18 It has been recognized as an important respiratory condition for more than 36 years since the groundbreaking publication by Sullivan et al. in The Lancet in 1981.9 OSA is usually a lifelong condition that requires long-term treatment such as continuous positive airway pressure (CPAP) in order to relieve symptoms, improve quality of life, mitigate the effect of daytime sleepiness on work-performance and driving-related accidents, and reduce the risk of cardiovascular comorbidity.1,1012

Current guidelines recommend regular review for individuals undergoing CPAP therapy and suggest a range of components that could be included such as assessment of daytime sleepiness using the validated Epworth Sleepiness Scale, adherence to CPAP, practical issues with masks and equipment, guidance regarding driving privileges, and weight and blood pressure monitoring. However, the guidelines give conflicting advice about the core components of a clinical review (Table 1) and how often this should take place, and there is therefore a need for consensus.

Components of a routine review recommended by current guidelines on the management of OSA.


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Table 1

Components of a routine review recommended by current guidelines on the management of OSA.

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An e-Delphi is a method that can be used for reaching consensus among a panel of experts where there is limited evidence on the priority attached to a range of items.13,14 Communication can take place by email, enabling participation by national and international participants over a short period of time.14 We conducted an international e-Delphi study to reach consensus on the important core components and optimal frequency of a clinical review in people using CPAP therapy for OSA.



We obtained ethical approval from the Usher Institute of Population Health Sciences and Informatics, University of Edinburgh (application number 1700).

e-Delphi Methodology

Stemming from the RAND Corporation in the 1950s,15 an e-Delphi delivers a series of questionnaires over (typically) three rounds in which expert panelists contribute their ideas independently and anonymously. In subsequent rounds individual responses may be influenced by feedback of the collective participant responses from previous rounds facilitating consensus.

Guideline Review and Pilot Work

We identified current guidelines, position statements, best practice statements/recommendations, and consensus statements for the management of adults with OSA therapy, searching Medline, Turning Research Into Practice databases, and Google Scholar using the following search terms “sleep apnoea/ apnea syndrome,” “CPAP therapy,” “national/international guidelines,” “clinical review,” and “follow up.” We scrutinized these documents for recommendations about the components of regular review of CPAP users and extracted all suggested elements of a review to form an initial list of possible components. Follow-up was explicitly stated as within scope for 7 of the 13 included publications in our study. We then piloted the e-Delphi process with 10 local sleep medicine clinicians who were asked to “sense-check” the review components from the literature review; any additional components they considered to be important would be added to the initial list.

Recruitment of an Expert Panel

Delphi panels are generally fewer than 50 participants; and most Delphi studies have included 20 to 30 respondents.14 We therefore invited, by email, 80 international experts with a view to recruiting approximately 30 participants to the study. The clinicians who were involved in the pilot work were excluded from the expert panel. Our recruitment strategy was to invite health care professionals who were actively involved in the review of people with OSA who were using CPAP therapy (eg, clinical academics, respiratory physicians, general practitioners, clinical nurse specialists/nurse practitioners, respiratory therapists, respiratory physiologists—health care scientists trained to support people using CPAP). We also invited up to five individuals with OSA using CPAP from a local service. Our aim was to encompass both clinical experiences with relevant academic expertise as well as individuals undergoing CPAP therapy. All suggestions, comments, and data were anonymized but participants were offered the option of being acknowledged in publications.

The Three Rounds of the e-Delphi

We followed recommended consensus methodology,13,15 and anticipated that it would require up to three rounds to reach consensus with a fourth round if required. The data collection sheets for the three rounds are in Appendix 1 in the supplemental material.

Round 1: Open Round

Initially we developed a data collection sheet (using an Excel spreadsheet) of potential clinical review components from our literature review of current guidelines combining any additional suggestions from our pilot work. The Round 1 data collection sheet was then emailed to the expert panel requesting any additional review components and/or free-text comments on the existing suggestions. Opinions were also sought regarding the importance of the timing and suggested frequency of clinical review. We collated all the additional suggested components to create the final list for prioritization in Round 2.

Round 2: First Scoring Round

This was the first scoring round and the panel were asked to review the list generated from Round 1 and identify the components that should be prioritized in a review using a scale of 1 to 5 (1 = unimportant and 5 = very important). We avoided ranking because the importance of specific prioritized components would depend on individual clinical context. The results were collated and a median score calculated for each component in preparation for Round 3.

Round 3: Second Scoring Round

The Round 3 data collection sheet included the median scores from Round 2 along with individuals' own Round 2 score. In Round 3 the participants were given the opportunity to revise their opinions (or not) on the priority of the clinical review components in light of the median findings of the previous round by again ranking each research question on a score of 1 to 5 (where 1 = unimportant and 5 = very important). We predicted an acceptable level of agreement on priority components with three rounds; however, a final fourth round (following the method of the Round 3) could be conducted if required.


We calculated the median scores for each component of the clinical review and the proportion of respondents scoring each item as 4 or 5. In discussion with the multidisciplinary team, consensus was defined as ≥ 75% agreement for the priority scores of 4 or 5. Prioritized components were grouped (eg, treatment acceptability, technical CPAP issues, sleepiness assessment, adherence, symptom resolution, assessing sleep quality, driving issues, quality of life, lifestyle issues/sleep hygiene) and mapped to a template that could be used to facilitate a standardized review.

Free-Text Comments From Participants

Participants were invited to contribute their additional free-text comments in all the rounds. We used an inductive approach to thematically analyze the free-text comments to identify the key issues from the perspective of the individual participants. The free-text comments from individual participants were not shared with the panel members and there was no opportunity for discussion among panel members because of the electronic study design.


Literature Review and Preparation of the Initial List

The literature review identified 13 national/international guidelines, best practice position, or consensus statements that made recommendations on the long-term management and follow-up of individuals undergoing CPAP therapy (Table 1 contains a summary of the recommended components). From the literature review an initial list of 12 review components was compiled. No additional components were suggested by the 10 local sleep medicine clinicians who piloted the process.

International Expert Panel

Of the 80 potential participants approached, 47 consented to participate from 21 countries (Europe n = 37, Australasia n = 5, Asia n = 3, North America n = 2). Professionals (some represented more than one group) encompassed respiratory physicians (n = 29), academicians (n = 25), journal editors (n = 9), specialist respiratory nurses (n = 5), respiratory physiologists (n = 3), respiratory therapists (n = 1), and individuals undergoing CPAP therapy (n = 6) (Table 2). A total of 44 participants completed Round 1; 41 and 40 participants completed Rounds 2 and 3, respectively. The four participants who withdrew were respiratory physicians.

Components of a clinical review, listed in percentage order of proportion of respondents who gave priority score of 4 or 5.


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Table 2

Components of a clinical review, listed in percentage order of proportion of respondents who gave priority score of 4 or 5.

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Final List of Components for Scoring

An additional 24 components were suggested in the free-text round and included in the list for the scoring rounds, making a total of 36 components.

Components Reaching Consensus Threshold

Seventeen components achieved a priority consensus of ≥ 75%, indicating agreement that these components were important to include in a clinical review. Table 2 shows the percentage consensus for all 36 components at the end of Round 3, listed in order of percentage agreement with the priority scores.

Themes Emerging From the Free-Text Comments

Table 3 lists illustrative quotes from the free-text comments providing contextual support for the rating decisions and highlighting some practical approaches to mode of delivery.

Themes from free-text comments.


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Table 3

Themes from free-text comments.

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Frequency of Review

Figure 1 shows responses on frequency and mode of review. Frequent review (face to face or telephone) was considered important to support initiation of CPAP following diagnosis and in the early months of use. Opinions on the frequency of review after CPAP was established was more varied with most participants suggesting 12- to 18-month follow-up, and more frequent reviews targeted to those with poor adherence. A flexible approach that offered “open access” or follow-up “on demand” was prioritized by 80% of participants. Almost half the respondents highlighted contexts (such as a specific request from a traffic agency, or before elective surgery) that might determine the need for a review. Follow-up via a telemonitoring option, where available, was acceptable. There was general agreement that the timing of the review should be flexible to meet the clinical and support needs of the patient as well as being compatible within the health care delivery context.

Frequency of review.


Figure 1

Frequency of review.

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Main Findings

This is the first study to provide an international consensus on the most important components that should be considered when reviewing people using CPAP therapy. From a list of 36 components, 17 reached consensus (≥ 75%) and were considered the most important to include during a CPAP therapy review. The components identified have been grouped into key categories: technical aspects (n = 8 components); general medical assessment (n = 7); sleepiness assessment (n = 3); symptom resolution (n = 3); acceptability of treatment (n = 2); adherence check (n = 2); assessing sleep quality (n = 2); driving issues (n = 2); quality of life (n = 2); and lifestyle issues/sleep hygiene (n = 2). The need for flexible follow-up arrangements was highlighted by the free-text comments indicating that clinical review arrangements should focus on individual patient needs.

Interpretation in Light of Other Literature

Current clinical guidelines regarding the review of CPAP users collectively suggest 10 components that should be included in a CPAP review with the guideline from the American Academy of Sleep Medicine being the most comprehensive and identifying 8 of 12 prioritized components.17 There is, however, wide variation in the guideline recommendations published between 200316 to 2016,26 highlighting the need for an international consensus on what is important to include in a clinical review and how often this should occur.

Some components (eg, asking if any problems with sleepiness while driving, self-reported assessment of sleepiness [eg, Epworth Sleepiness Scale], checking for any mask interphase issues) were strongly prioritized in our e-Delphi study but were not always recommended by the guidelines. Specifically, current guidelines do not highlight checking the apnea-hypopnea index (AHI) in the downloaded CPAP data despite the priority accorded by most e-Delphi participants to assessing improvements in AHI. In the United Kingdom, this priority may reflect the recently updated guidance from the Driving and Vehicle Licensing Agency, which states that in moderate to severe OSA subsequent licensing will require control of the condition; improved sleepiness; and treatment adherence.27 This is an important finding of our e-Delphi study and driving-related issues need to be given higher priority in future clinical review and guideline development.

Our study identified a number of components that were considered as being less important (< 75%) suggesting these may be optional and included according to clinical judgement (Table 2). For example, “asking about comorbidities”, which achieved a rating just under the priority threshold, will be important in some clinical contexts. Ongoing/long-term review also provides the opportunity for education/support and reinforcement of treatment rationale in individuals undergoing CPAPs.

Asking about quality and quantity of sleep, sleep routine times and work schedules/shift patterns, measuring patients' quality of life, and reviewing patients' preparedness to continue with treatment all reached a priority consensus of > 75% although few current guidelines specifically recommend these components. The consensus gained from our e-Delphi study has highlighted the importance of considering including these components in a review. The priority attached to checking practical maintenance of CPAP equipment depended on the organization of sleep medicine services; in some systems this was not part of a clinical review.

One option for implementing these clinical review components in CPAP users is to provide a clinical review template. Although opinions vary on the use of templates in clinical practice, they can facilitate a structured process and improve consistency of care.28 However, there are limitations to the use of clinical templates; for example, they may not address all issues with CPAP usage from a patient's perspective so some flexibility in their use is important. Building on our findings we have outlined a suggested clinic review template based on the components prioritized by the e-Delphi respondents that could assist sleep medicine clinicians to provide a structured review (Table 4).

Outline of a sleep clinic review template.


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Table 4

Outline of a sleep clinic review template.

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A key finding from our e-Delphi study is that there needs to be flexibility in the delivery of services—both in frequency and mode. Early and frequent review is recommended as a priority for new CPAP users and those having difficulty with adherence, or practical problems such as treatment side effects, and then reducing to annual/ biannual review when stable. The option of offering an “open access” service in which the patient could determine his or her need for review appealed to 80% of the respondents in our study. With the ever-increasing demand for sleep medicine services globally this may be seen as an attractive option for health care providers; however, there is currently no published literature to inform this practice. Furthermore, with the rise in the implementation of sleep tele-medicine services CPAP review can be facilitated with tele-monitoring and overseen remotely.

Strengths and Limitations

We generated an extensive list of potential components of a CPAP therapy clinical review by amalgamating recommendations from current guidelines, best practice, and position statements with suggestions from an international multidisciplinary panel of participants of clinicians/academics involved in this field and also individuals undergoing CPAP therapy. Interpretation and development of the outline review template followed a structured mapping of components. Forty participants (exceeding our recruitment target) completed all three rounds of our study electronically; only one person withdrew between the two scoring rounds enabling the consensus process. An important strength of our study is that the participants were from a range of health care backgrounds involved in the delivery of sleep medicine services, representing 21 countries with a broad range of economic backgrounds and health care systems. Although the number of participants recruited to our expert panel is larger than in other e-Delphi studies23,24 they may not represent the full range of perspectives from sleep medicine clinicians/providers as the delivery of sleep medicine services varies widely in health care systems globally. Providing an initial list of components derived systematically from guidelines would have helped clarify the process for participants but will have influenced their suggestions, though the international expert panel of clinicians/academics and CPAP therapy users trebled the list of components. A consensus conference would have allowed a nuanced discussion but, for logistical reasons, would have restricted the number of participants, in particular reducing the international perspective. However, our e-Delphi actively encouraged free-text comments throughout all rounds of the study, which we analyzed thematically to provide insights into the results of scoring.


Our international expert panel agreed that the most important components of a clinical review of people using CPAP therapy to treat OSA were assessing: treatment acceptability; technical aspects of therapy; use of a validated sleepiness assessment tool; recording adherence/efficacy verbally or by data download via memory card/remote monitoring; symptom resolution; driving issues; sleep quality; quality of life and lifestyle issues/sleep hygiene. We have mapped these components into a suggested sleep medicine review template that may assist clinicians to conduct a patient centered, structured, and evidence-based clinical review. There were diverse opinions on the optimal frequency of review but general agreement that relatively frequent review should be undertaken in patients with a new diagnosis. Long-term follow-up may be less frequent, or potentially “on demand,” and can be provided by a range of professionals with the option of using telemonitoring where available. Feedback on the utility of the template is welcomed, so that our findings can be refined to inform future guideline recommendations and the delivery of care for people with OSA using CPAP.


Work for this study was performed at the Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh. All authors have seen and approved the manuscript. The authors disclose receipt of the following financial support for the research, authorship and/or publication of this article: The Scottish Association of Sleep Apnea (SASA) have provided financial support towards tuition fees for PM for academic years 2017–2019. NHS Dumfries and Galloway have provided support for tuition fees for PM for academic year 2017–2018. The authors declare no potential conflicts of interest with respect to the research, authorship, and/ or publication of this article.



apnea-hypopnea index


continuous positive airway pressure


obstructive sleep apnea


The authors thank NHS Dumfries and Galloway for granting study time to PM to undertake this e-Delphi study. They are also grateful to the Scottish Association of Sleep Apnoea (SASA) for awarding research scholarships to PM in 2014–2015 and 2017–2019. We also acknowledge the contribution of the following members of the expert panel: William Anderson, Ferran Barbe, James Boyd, Marie Bruyneel, Catherine Buchan, Christopher Carlin, David Comer, Frankie Clavaud, Wendy Douglas, Mark Elliott, Francesca Fanfulla, Patrick Fitch, Jan Hedner, Mark Howard, Juan Fernado Masa Jimenez, Julian Leggett, Pei Lin Lee, Eric Livingston, Claudia Maldonado, Tom MacKay, Ralston McKay, Belinda Miller, Mark Miller, Matt Naughton, Georg Nilus, Jean-Louis Pepin, Alex Perkins, Victor Rolando, Silke Ryan, Chamara Senaratna, Stuart Schembri, Robin Smith, Gail Spacic, Patrick Strollo, Chris Turnbull, Johan Verbraeken, Michele Vitacca, Marija Vukoja, Liz Walker, Kim Ward. Author contributions: conceived and designed the e-Delphi; PM, SL, BMcK and HP; performed the e-Delphi: PM with SL, BMcK and HP; analyzed the data: PM, SL, BMcK and HP; wrote the paper: PM, SL, RP, BMcK and PM and HP are guarantors.



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