Table 1

Data extraction form

Study characteristics	Extracted data
General information	First author last name Title Journal Publication year Country of study/continent/multinational Publication type: journal, abstract, dissertation, unpublished trial, report
Introduction	Aims of the study Study research question Study population: number of subjects using NIV, mean age, age range, gender, primary underlying condition, comorbidities
Design	Study design: Quantitative: randomised controlled trial, non-randomised controlled trial, controlled before-after studies, observational, cross-sectional Qualitative: case series, ethnography, grounded theory, phenomenology, other, mixed methods Sample size Intervention type, NIV term used, interface type, duration of intervention, cointerventions Statistical analysis methods used Control group: number of control subjects, y/n, intervention in control group
Outcomes measures (whether self-reported or objective tools)*	Primary outcomes Secondary outcomes Adverse outcomes Duration of the follow-up
Authors conclusions	Positive, negative, neutral, indeterminate
Gaps and limitations identified by authors