Table 2

Studies included

First author [ref.]	Topic, focus and questions	Paradigm and method	Setting and sample	Findings	Limitations
Almeida [33]	“Patient preferences and experiences of CPAP and oral appliances for the treatment of obstructive sleep apnea: a qualitative analysis” To better understand patients' perspectives and preferences about treatment with CPAP and OA devices for obstructive sleep apnoea	Qualitative Qualitative analysis of four focus group sessions In-depth interview	Canada University of British Columbia Sleep Apnea Clinic 22 participants (13 male) Age 36–85 years	Many factors impact patients' experience with their treatment device and that their treatment needs are not only physical but also relate to their lifestyle The authors suggest that matching therapy to patient preferences may help identify the most appropriate treatment, and increase the likelihood of adherence	Findings may not be representative of all OSA patients The qualitative research approach used is not clearly defined
Ando [30]	“Experience of long-term use of non-invasive ventilation in motor neuron disease: an interpretative phenomenological analysis” To explore patients' perceptions of NIV treatment evolve over time and how this was reflected in their adherence to NIV	Qualitative Interpretative phenomenological analysis Semistructured interviews	UK NHS neurology and respiratory outpatient clinics in Liverpool 5 patients (4 male) Age 51–75 years	Physical benefits gained from NIV were direct precipitators of psychological gains A more positive attitude was seen in individuals who appreciated gains in energy and empowerment, while a more negative attitude was associated with perceptions of hopelessness over the future A reinforced approach to NIV was observed when the essentiality of NIV was acknowledged and this was sometimes accompanied by fear of death	Small sample Interviews were normally conducted verbally Some strategies were employed to mitigate communication difficulties with patients who had dysarthria but the strategies are not specified
Ando [34]	“Why don't they accept non-invasive ventilation? Insight into the interpersonal perspectives of patients with motor neurone disease” To understand why some MND patients decline or withdraw from NIV	IPA Semistructured interviews	UK 9 patients with MND (7 male) Age 40–79 years	Four themes were identified: preservation of the self, negative perceptions of NIV, negative experience with healthcare services, and not needing NIV Further analysis identified the fundamental issue to be the maintenance of perceived self, which was interpreted to consist of the sense of autonomy, dignity and QoL	Only patients who had declined or withdrawn from NIV treatment at an early stage were interviewed It would be informative to include patients who declined the treatment in different stages of NIV use
Ando [29]	“Exploring reasons for declining and withdrawing from non-invasive ventilation among motor neurone disease patients” To understand why some individuals with MND withdraw from NIV	Qualitative Phenomenological approach using IPA Semistructured interviews	UK Purposive sampling WCNN and UHA 12 patients (10 male) Age 64–79 years	Illness could have a negative impact on patients' perception of themselves, consequently affecting their decision over NIV use NIV may generate fear, which may form a negative belief about NIV, leading to a rejection of it due to a sense of the loss of control over the machine A poor impression of the healthcare service may have impact on participants' willingness to engage with the hospital in consideration of NIV establishment Individuals' understanding of their condition influences perception regarding the need of NIV	Less selective homogeneity Only males participated Novice researcher (MPhil student)
Ayow [35]	“Factors influencing the use and nonuse of continuous positive airway pressure therapy: a comparative case study” To identify facilitators and barriers toward CPAP therapy after treatment initiation among patients with OSA	Qualitative Phenomenological approach Semistructured interviews	Canada Sleep disorder clinic Purposive sampling 8 patients (4 male) Age 43–48 years	Social comparison and stigma influenced patients in either using or abandoning CPAP Absence of supportive relationship can be a factor toward not using NIV for most patients	Theoretical saturation did not occur due to limited resources
Bakker [36]	“Continuous positive airway pressure treatment for obstructive sleep apnoea: Maori, Pacific and New Zealand European experiences” To explore Maori, Pacific and NZ European patients' experience of CPAP treatment	Qualitative Ethnography Semistructured interviews	New Zealand Community sleep investigation centre, purposive sample. 5 Maori , 5 Pacific, and 8 NZ Europeans Age 30–71 years	Patients in all three groups reported that they had little knowledge of OSA or CPAP prior to treatment initiation All groups identified barriers to treatment (both at the CPAP initiation phase and long term), reported feelings of being “overwhelmed” with information during the initial CPAP education session and discussed the importance of successful role models	Sleep service model used at the centre is not used throughout New Zealand
Ballangrud [37]	“Clients' experiences of living at home with a mechanical ventilator” To explore how patients experience living with home mechanical ventilation and how they experience care and supervision of healthcare personnel	Inductive qualitative approach Interviews/telephone	Norway Community setting 10 patients (7 male) Age 18–75 years	Two main themes emerged Theme 1 Having a home ventilator enhances QoL: “a life worth living” The ventilator treatment builds up strength and improves wellbeing Participants emphasised that it was important to feel in control of their own situation and had an overriding wish to live a normal and active life Theme 2 Competence and continuity of healthcare personnel are factors for success The experience was that competence and follow-up by healthcare personnel varied, and that good quality teaching and information were important	Four out of 10 participants received respiratory support via a tracheostomy The study does not give separate data from those who used invasive ventilation and NIV The experience of using a mask could be different from that of not using a mask
Ballangrud [37] Broström [38]	“Putative facilitators and barriers for adherence to CPAP treatment in patients with obstructive sleep apnea syndrome: a qualitative analysis” To explore the experiences of adherence to CPAP treatment in patients with OSA syndrome	Qualitative Explorative inductive approach Semistructured interviews	Sweden CPAP clinics, one university hospital and one county hospital Purposive sampling 23 patients (13 male) Age 33–74 years	Findings show that adherence to CPAP treatment is a complex and multifaceted problem involving patient-, treatment- and condition-related factors, and experiences related to social situation and the healthcare system	The approach used by the authors does not allow for quantification of the relative importance (magnitude and prevalence) of the individual factors or how these factors relate to different degrees of objectively measured adherence (e.g. they did not know whether patients with an objectively good adherence described the same facilitators and barriers as patients with objectively poor adherence)
Broström [23]	“A mixed method evaluation of a group-based educational programme for CPAP use in patients with obstructive sleep apnea” To describe adherence to CPAP treatment knowledge about OSA/CPAP, as well as OSA patients' perceptions of participating in a group-based programme using problem-based CPAP initiation	Qualitative and quantitative Sequential explanatory mixed-method design Medical devices or self-rating scales Phenomenological approach Semistructured interviews	Sweden Linkoping University Hospital Strategically selected 25 patients (14 male) Age 49–65 years	Patients value an adequate introduction and presentation of the schedule before starting CPAP Patients strive to become adherent CPAP users Patients usually have negative feelings before treatment, which increase after having had practical experience with the treatment	A large number of participants suffered from hypertension and other comorbidities This might have had an impact in participant's perception of the appropriateness of the CPAP treatment (e.g. a chance to enhance alertness, reduce blood pressure and alleviate complications)
Broström [23] Dickerson [39]	“Life changes in individuals diagnosed with sleep apnea while accommodating to continuous positive airway pressure (CPAP) devices” To longitudinally discover OSA patients' experiences with CPAP	Qualitative Retrospective Heideggerian hermeneutic phenomenology plus pilot of Calgary OSA QoL tool Semistructured interviews	USA Sleep centre Purposive sampling 20 patients (9 male) Age 31–72 years	Patients face the difficulties and troubles acclimating to the CPAP device Some patients persist through NIV treatment regardless of its adverse effects	The study involved a survey that participants who had no spouse or significant other said questions related to intimate relationships were not appropriate
Dickerson [40]	“CPAP devices: encouraging patients with sleep apnea” To understand patients' experiences and difficulties using CPAP	Qualitative Heideggerian hermeneutic phenomenological approach Semistructured interviews	USA Urban medical centre and rural hospital 17 participants (12 male) Age 40–73 years	New NIV patients may gain hope by witnessing other patients living with the NIV machine and coping with the difficulties Patients need practical information to provide context for understanding required changes in lifestyle	Investigation of experiences using CPAP was limited to the effect of patient support group participation on encouragement to use CPAP
Dimech [28]	“Critical care patients' experience of the helmet continuous positive airway pressure” To explore critical care patient's experience of helmet CPAP	Qualitative Phenomenological approach Semistructured interviews	UK Purposive sampling NHS foundation hospital 6 male patients Age ≥18 years	Themes revealed several areas that highlighted the patient's experience Entrapment Confusion “Helping me breathe” Liberation Relief Trust Endurance Adaptation	Novice researcher (MSc student) Only males participated The study was limited to only one hospital and patient group
Fung [41]	“Human factors/usability barriers to home medical devices among individuals with disabling conditions: in-depth interviews with positive airway pressure device users” To explore in detail the types of difficulties experienced by patients with physical/sensory impairments who use PAP devices, as an initial step in designing a questionnaire to survey users about this topic	Qualitative Descriptive study Semistructured interviews	USA Community sleep centre, purposive sample. 9 patients (8 male, 5 Caucasian) Age ≥50 years	Participants reported CPAP devices failed to meet the needs of individuals with physical/sensory impairments (e.g. tremor, poor depth perception, paresis) by requiring patients to perform manually difficult tasks (e.g. inserting CPAP parts through small apertures, attaching parts using a twisting motion and lifting arms overhead to apply CPAP headgear) These demands contributed to patients' frustration with and reduced use of the home medical device	All patient participants described impairment-related difficulty with their PAP devices because researchers recruited patients with physical/sensory impairments who use PAP devices The study involved carers as participants: however, it does not give patients' views separately, which may differ from carers'
Fung [41] Gale [42]	“Adapting to domiciliary non-invasive ventilation in chronic obstructive pulmonary disease: a qualitative interview study” To explore experiences of domiciliary NIV in COPD, to understand decision making processes and improve future palliative care	Constructivist grounded theory Semistructured interviews	UK 20 COPD patients Age 52–83 years	Patients reported symptomatic benefit, which generally outweighed negative experiences and led to continued use	The sample lacked ethnic diversity; it was not reflective of the local population; however, it was reflective of those on NIV Researchers were not able to return after analysis to further explore themes; therefore, data saturation may not have been reached
Hu [22]	“Life experiences among obstructive sleep apnoea patients receiving continuous positive airway pressure therapy” To generate a descriptive theoretical framework for experiences among OSA patients undergoing CPAP therapy	Qualitative Grounded theory Semistructured interviews	Taiwan Convenience sample 22 patients (18 male) Age 37–68 years	Analyses indicated seven subcategories of OSA patients with CPAP 1) Seeking medical information 2) Difficulties with CPAP 3) Trial and error for the “right” CPAP 4) Long scheduled waiting times 5) Wondering 6) High expectations 7) Getting back good health	Limitations to the study not well explored Convenience sample
IngadÓttir [43]	“Technological dependency – the experiences of using home ventilators and long-term oxygen therapy: patients' and families perspective” To describe patients' and families experience of long-term home treatment with NIV during sleep with or without additional oxygen therapy	Qualitative IPA and narrative analysis Semistructured interviews	Iceland Landaspitali University Hospital 6 patients (3 males) Age 45–70 years	The themes that emerged from the data were life-saving treatment; compassion and understanding central amid use of complex machines wanting to be seen as healthy dominance of technological thinking sustained work in maintaining the treatment	Sampling strategy is not clearly discussed Limitations to the study are also not clearly defined
Ingado´ttir [43] Kvangarsnes [44]	“Narratives of breathlessness in chronic obstructive pulmonary disease” To explore patient perceptions of COPD exacerbation and the patients' experiences of their relations with health personnel during care and treatment	Qualitative Narrative inquiry In-depth interviews	Norway ICU Purposive sampling 10 patients (5 males) Age 45–85 years	Two main themes emerged Breathlessness Trust/power dimension Breathing problems led to a situation where patients experienced both situation of trust and power	The first author was an intensive care nurse, which may have influenced the interpretations Interviews were transcribed and then translated from Norwegian into English; this may have a impacted the validity of the research, as the context and meaning may be lost in translation
Lemoignan [45]	“Amyotrophic lateral sclerosis and assisted ventilation: how patients decide” To elicit factors that are pertinent to their decision-making process about assisted ventilation	Qualitative Phenomenology methodology Semistructured interviews	Canada Canadian MND clinic Maximum variation sampling strategy 9 patients (6 males) Age 46–72 years	Six main themes emerged relevant to decision-making about assisted ventilation 1) The meaning of the intervention 2) The importance of context 3) The importance of values 4) The effect of fear 5) The need for information 6) Adaption to or acceptance of the intervention	The interviewer knew the patients already; as such, some aspects of her clinical role may have influenced the findings
Lindahl [25]	“Meanings of living at home on a ventilator” To illuminate the meanings of being on a ventilator and living at home	Qualitative Phenomenological-hermeneutic method Semistructured interviews	Sweden Community setting 9 patients (3 males) Age 27–72 years	The meanings of being on a home ventilator were interpreted as maintaining autonomy and persistence in interaction with the ventilator and other human beings, and being able to raise above oneself and one's personal boundaries in order to live a good life	Two participants were using invasive ventilation/tracheostomy It is difficulty to identify data from these two participants Their experience may not have been the same as participants who used NIV
Lindahl [25] Lindahl [26]	“On being dependent on home ventilation: depictions of patients' experience over time” To describe the meanings and experience of being dependent on mechanical ventilation and living at home	Qualitative Phenomenological hermeneutics Semistructured interviews	Sweden Community hospital 13 patients (8 males) Age 52–81 years	Ignorance and negative attitudes on the part of professionals working and/or managing care in ventilated patients' homes are interpreted as causing suffering and intensifying a closed-in mode of being	Interviews included patients who were ventilated invasively with tracheostomy Their experience may not have been the same as patients using NIV
Lindahl [27]	“On becoming dependent on home mechanical ventilation” To illuminate meanings of becoming dependent on home mechanical ventilator treatment	Qualitative Phenomenological hermeneutics	Sweden Hospital and community 13 patients (8 males)	The findings imply possibilities and deficiencies in meeting patients' existential needs, such as helping them to breathe spiritually by supporting them as they get their breath after such a life-changing event as becoming dependent on a ventilator	The study had less selective homogeneity; this may have affected the findings of the study by either over- or underrepresenting the impact of the phenomenon Two participants used invasive ventilation and most participants had varying prognosis, i.e. chest deformity, neuromuscular disorder, stroke, rheumatic disorder, spinal cord injury and obesity hypoventilation
Piggin [46]	“The experience of non-invasive ventilation in motor neurone disease: a qualitative exploration” To explore MND patients' experiences of respiratory impairment and NIV use	Qualitative Cross-sectional and longitudinal studies IPA Interviews	UK Community/patients' own homes. Purposive sampling Cross-sectional study 5 male patients Age 60 – 72 years Longitudinal study 26 patients (19 male)	This study found complex emotional and psychological responses to NIV, including reluctance to initiate, fear of dependence and threats to control Respiratory masks had a significant negative impact on identity and self-esteem; However, patients felt that the positive physical effects of NIV made this experience acceptable	The study was conducted in two parts: the researcher started with a cross-sectional study as a preparative step for a subsequent longitudinal study Study was conducted as part of a doctoral degree The study was only limited to patients with MND
Piggin [46] Sawyer [24]	“Differences in perceptions of the diagnosis and treatment of obstructive sleep apnea and continuous positive airway pressure therapy among adherers and non-adherers” To describe OSA patients' beliefs and perceptions of the diagnosis and CPAP treatment that importantly differentiate adherent from nonadherent patients prior to and after the first week of treatment when the pattern of CPAP use is established	Qualitative and quantitative Mixed-method concurrent, nested study Semistructured interviews and software (RemStar Pro^# CPAP system)	USA Sleep clinic, urban medical centre Purposive sampling 15 participants (13 male) Age 41–66 years	Description of the meaning of being diagnosed with OSA and treatment with CPAP, which in turn influenced their decision to accept or reject treatment and the extent of CPAP use Differences in beliefs and perceptions at diagnosis and with CPAP treatment were identified among CPAP adherers and nonadherers	Study participants were predominantly male with severe OSA who had relatively high educational background A more heterogeneous sample of OSA patients is needed to explore the relationship of sex, disease severity, symptom perception and disease-specific literacy with CPAP adherence
Shoukry [32]	“Treatment experience of people with obstructive sleep apnoea seeking continuous positive airways pressure device provision through community pharmacies – a role for pharmacists” To explore the unique experiences of people with OSA who source treatment through community pharmacies	Qualitative Phenomenological approach In-depth semistructured interviews	Australia Community pharmacies in greater Sydney region Purposive convenience sample 20 participants Age 20–75 years	There was lack of OSA awareness ensuing delayed diagnosis, suboptimal provision of information about CPAP, and personal/psychosocial characteristics were predominant influences on CPAP use and positive CPAP provision experiences in community pharmacies	The demographics of the interviewing researcher (pharmacy student) may have influenced a socially desirable response about pharmacy services. This demonstrates potential bias as those who accepted participation may be the ones who have experienced positive experiences with the pharmacy
Slater [47]	“An investigation of the experiences of patients receiving non-invasive ventilation” To explore and conceptualise the experiences of patients who had received NIV for COPD	Qualitative Phenomenological interpretive approach Semistructured interviews	UK Community Purposeful sampling 5 patients (3 male) Age 64–82 years	Physical issues Mask unpleasant and frightening Paternalism and patient choice Patients receiving NIV for AECOPD are under-consulted when treatment decisions are being made Need for patients to have a better understanding and involvement with their treatment to promote active participation in their own care	Novice researcher (MSc student), may have influenced patient's response Most of the participants were known to the researcher and this may have limited criticisms of treatment for fear of any adverse effects this may have on their future care
SØrensen [20]	“Striving for habitual well-being in noninvasive ventilation: a grounded theory study of chronic obstructive pulmonary disease patients with acute respiratory failure” To develop a theoretical account of the pattern of behaviour in patients with ARF due to COPD who undergo NIV in a hospital setting	Qualitative Grounded theory Observations Semistructured interviews	Denmark University hospital 21 patients (11 male) Age 43–81 years	During NIV, patients' behavioural patterns may relate to their breathlessness, the sensation of being restrained by the mask and head gear, and individual coping with the side-effects Patients with COPD undergoing NIV tend to use discomfort control as a strategy and drawing on routines, proactive participation and mobilising strength are strategies that they use to achieve control	Findings do not reflect all details of the entire range of behaviour and strategies among COPD patients with ARF
Sørensen [20] Sundling [48]	“Patients' with ALS and caregivers' experiences of non-invasive home ventilation” To describe the patients' with ALS and their caregivers' experience of NIV	Qualitative Phenomenological hermeneutic method In-depth interviews	Sweden University hospital 7 patients (5 male), 8 care supporters Age 45–75 years	Three main themes emerged Getting to know the ventilator Embracing the ventilator Being on the ventilator Patients can effectively benefit from improved sleep by NIV Patients can experience several problems connected to the mask	Some of the patients were very ill and reluctant to answer all questions; this may have limited the amount of data collected
Torheim [49]	“How to cope with the mask? Experiences of mask treatment in patients with acute chronic obstructive pulmonary disease-exacerbations” To focus on important aspects and issues associated with BiPAP mask treatment in acute exacerbation of COPD based on the experiences of patients and nurses	Qualitative Phenomenological Approach In-depth interviews	Norway University hospital Purposive sampling 5 patients (2 males) One focus group with 8 nurses Age 45–78 years	Patients have difficulties in coping with mask Patients felt tension between dependence and autonomy Patients feel confident in using the mask when receiving skilled help Patients need breaks between sessions to give some respite from the pressure and pain of the NIV mask	Lack of generalisability due to the population The study was limited to only one hospital The study made no attempt to reach thematic saturation, which is a potential methodological limitation
Torheim [50]	“How do patients with exacerbated chronic obstructive pulmonary disease experience care in the intensive care unit?” To gain insight into how patient with advanced COPD experience care in the acute phase	Qualitative Phenomenological analysis Semistructured interviews	Norway Hospital 10 patients (5 male) Age 45–85 years	Three central themes emerged: Preserving the breath of life Vulnerable interactions Opportunity for better health Patients experienced themselves as being in a state where life was about to end Patients were totally dependent on technology Lessening of anxiety in NIV through several coping strategies, and faith in one's ability to cope with receive greater focus when patients' sense impressions are interpreted and understood by the nurse in a manner which creates trust and the NIV treatment may succeed	The findings represent patient experiences of an acute and life-threatening condition; therefore, most of the patients were in an altered mental state and did not remember all from the acute stage
Torheim [50] Tyrrell [31]	“A preliminary study of psychological factors affecting patients' acceptance of CPAP therapy for sleep apnoea syndrome” To explore patients' understanding and experiences of their OSA and of the CPAP therapy and their reasons for stopping	Qualitative Exploratory Retrospective–semistructured interviews and survey	France French respiratory homecare network Purposive sample 9 patients (8 male) Age 32–70 years	Patients' understanding of illness and CPAP treatment was variable Seven patients specified that they abandoned CPAP treatment because of their negative experiences Authors concluded that there was a need for more comprehensive psychological evaluation in conjunction with medical evaluation at the start of CPAP in order to identify factors associated with successful and unsuccessful adoption of CPAP therapy	Only one female of out nine patients was interviewed Duration of interviews not stated Study interviewed patients who abandoned CPAP after several months of treatment and excluded those who abandoned it within days or weeks; the views of patients who abandoned the treatment at an early stage would have been interesting
Van de Mortel [21]	“Client perceptions of the polysomnography experience and compliance with therapy” To generate theory about clients' perceptions of polysomnography, and the relationships between these perceptions and compliance with therapy	Qualitative Grounded theory approach Semistructured interviews	Australia Hospital setting 10 patients (8 male) Age 59–75 years	Compliance with therapy related to the degree of benefit derived by the client In addition, there were problems with the process of diagnosis and follow-up that impacted on client satisfaction and may have influenced their compliance These findings have highlighted issues that have been used to generate theories that will be tested in future research	The authors acknowledged that lower CPAP compliance in this study may be related to difficulties involved in operating a small regional hospital with less resources
Van de Mortel [21] Veale [51]	To seek an in-depth analysis of how patients live with sleep apnoea by allowing them an open discourse and analysing the text of their statements	Qualitative Retrospective discourse analysis Semidirective interviews	France Pulmonary rehabilitation unit, purposive sample 30 participants (sex not given) of whom 15 were commencing CPAP Age 39–74 years	Two questions explored the difficulties with and long-term expectations of CPAP CPAP was described as a problem or nuisance with noise and nasal mask problems raised 21 times CPAP users claimed better sleep on CPAP but expressed general dissatisfaction 17.7% of respondents hoped for a “miracle cure”	Assessment of patient experiences focused on concerns living with OSA rather than CPAP The use of discourse analysis is questionable; the approach places particularly heavy reliance on the insights and intuition of the researcher for interpreting the data
Willman [52]	“Experiences with CPAP treatment in patients with obstructive sleep apnea syndrome and obesity” To describe patients' experiences of CPAP treatment in obese individuals with moderate-to-severe OSA syndrome	Qualitative Semistructured interviews	Sweden Dept of Lung Medicine, Uppsala University Hospital Consecutive sampling 15 patients (8 male) Age 41–71 years	Experiences of CPAP use differed between individuals but common for all was the existence of both drawbacks and benefits Difficulties in adapting to the CPAP may be the cause of many quitting Some patients persisted through difficulties	Limited to participants with obesity

CPAP: continuous positive airway pressure; OA: oral appliance; NIV: noninvasive ventilation; MND: motor neurone disease; OSA: obstructive sleep apnoea; NZ: New Zealander; PAP: positive airway pressure; COPD: chronic obstructive pulmonary disease; ARF: acute respiratory failure; BiPAP: bilevel positive airway pressure; IPA: interpretative phenomenological analysis; QoL: quality of life; NHS: National Health Service; WCNN: Walton Centre for Neurology and Neurosurgery; UHA: University Hospital Aintree; ICU: intensive care unit; AECOPD: acute exacerbation of chronic obstructive pulmonary disease. ^#: Respironics, Murrysville, PA, USA.