Inclusion and exclusion criteria
| Criteria | Rationale |
| Inclusion | |
| Studies with a focus on adult (18 years and older) people's experiences of NIV treatment, using either an acute BiPAP machine or a CPAP machine | Studies that examined the experiences of NIV treatment in older people have been very limited; therefore, broadening the search to include all NIV studies with an adult population was considered, in order to provide a general perspective into the experiences NIV in people with respiratory failure |
| Studies of populations of adults receiving NIV treatment on a short-term (using acute BiPAP) or long-term basis (using CPAP) | To broaden the search, because there are no available studies that focus on older people receiving NIV via BiPAP in acute setting. Broadening the study selection provided relevant studies linked to older people's experiences of undergoing NIV treatment |
| Studies using qualitative methods or mixed methods with a qualitative section that met the inclusion criteria | The review focused on the views of people undergoing NIV treatment, for which qualitative or mixed methods studies are appropriate |
| Studies written in English and that were peer reviewed | Due to limited time and resources, and possible translation errors, non-English language studies were not included |
| Exclusion | |
| Studies that reported views of healthcare professionals and carers only, or children | Our review concerns NIV experiences as lived by the people undergoing treatment |
| Studies that focussed on experiences of people receiving invasive ventilation (e.g. tracheostomy) | Application, design and function of invasive ventilation differ markedly from NIV; therefore, it was considered that treatment experiences may be different |
NIV: noninvasive ventilation; BiPAP: bilevel positive airway pressure; CPAP: continuous positive airway pressure.