Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Patients with obesity and breathing failure often require a mask overnight to help them breathe. At present, the length of hospital stay for such mask ventilation [Non Invasive Ventilation (NIV)] is between 4.5 and 6 days. There is no evidence to support the clinical or cost effectiveness of setting up mask ventilation on an outpatient basis in the clinic, compared to inpatient set-up on the ward by specialist respiratory nurses, although this is increasingly used as a strategy in smaller units without inpatient facilities. In essence, financial constraints are driving a practice that has no current evidence base in this patient group. Obese patients with long-term respiratory failure have complex physiological changes and often require much higher mask ventilation pressures than other patients needing hospital admission to gain control of their sleep disordered breathing. This will be the first study to test whether outpatient set-up mask ventilation in obese patients with chronic respiratory failure is clinically effective and cost effective at 3 months.

Who can participate?
Stable obese patients attending for management of chronic respiratory failure related to obesity.

What does the study involve?
Patient are randomly allocated to one of two groups: intervention and standard treatment. Intervention group patients are initiated on NIV during an optional outpatient clinic review during which an arterial blood gas measurement (from the wrist) is taken to confirm the presence of long-term respiratory failure. Patients in the standard treatment group are admitted for an inpatient initiation of NIV.

What are the possible benefits and risks of participating?
By taking part in the research, participants are helping shape the future management of patients with the same condition. All of the other research tests are not invasive so there will be no direct risk to participants.

Where is the study run from?
1. St Thomas' Hospital, London, UK (lead site)
2. St James' Hospital, Leeds, UK
3. Royal Brompton Hospital, London, UK
4. Royal Free Hospital, London, UK
5. University Hospital of Grenoble, France
6. University Hospital of Rouen, France

When is the study starting and how long is it expected to run for?
April 2014 to April 2018

Who is funding the study?
Phillips Respironics (UK)

Who is the main contact?
Gill Arbane (Project Coordinator)

Trial website

Contact information



Primary contact

Ms Gill Arbane


Contact details

St Thomas's Hospital
249 Westminster Bridge Road
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

16392; IRAS 139750

Study information

Scientific title

Medium cost effectiveness of automated non-invasive ventilation outpatient set up vs standard fixed level non-invasive ventilation inpatient set up in obese patients with chronic respiratory disease: a randomised controlled trial



Study hypothesis

The OPIP Trial will be a randomised controlled trial by an international group to evaluate the cost effectiveness on an automated non-invasive ventilation outpatient set up vs. standard fixed level non-invasive ventilation inpatient set up (mask ventilation) for initiation for obese patients with chronic respiratory failure. OPIP will evaluate standard treatment costs and patients health related quality of life and change in a gas exchange.

Ethics approval

Current ethics approval as of 10/02/2020:
Approved 27/05/2014, NRES Committee London- Westminster (Bristol REC Centre Level 3, Block B, Whitefriars Lewins Mead, Bristol, BS1 2NT; +44 0117 342 138;, ref: 14/LO/0414

Previous ethics approval:
NRES Committee London, Westminster, 27/05/2014, ref: 13/LO/1362

Study design

Randomised; Interventional; Design type: Not specified

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Topic: Metabolic and endocrine disorders, Respiratory disorders; Subtopic: Metabolic and Endocrine (all Subtopics), Respiratory (all Subtopics); Disease: Metabolic & Endocrine (not diabetes), Respiratory


A randomised controlled trial of Outpatient vs Inpatient NIV Set Up, randomised by site, gender and previous mask use, to determine clinical and cost effectiveness of outpatient set up. All patients will keep a record of Health Care Utilisation and be followed up with telephone calls from the research team throughout the trial.

Patients will be seen at baseline, 6 weeks and 3 months, primary outcome measure will be cost effectiveness.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Cost effectiveness of standard treatment costs and health related quality of life (SRI and Eq-5D); Timepoint(s): Baseline, 6 weeks and 3 months

Secondary outcome measures

Not provided at time of registration

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Obese patients with chronic respiratory failure
2. Age >18 years
3. Chronic hypercapnia (daytime pCO2>6.5kPa)
4. Evidence of sleep disordered breathing on overnight oximetry study (4% oxygen desaturation index>10 events per hour and/or >30% of the total analysis time with an SpO2 <90%)
5. BMI>35kg/m2
6. FEV1/FVC>70%
7. Tolerates NIV>4 hours on first night during initiation of NIV

Participant type


Age group




Target number of participants

Planned sample size = 82, UK sample size = 62

Participant exclusion criteria

1. Persistent hypercapnic respiratory failure with acidosis (defined as pH <7.30)
2. Severe hypoxic and/or hypercapnic respiratory failure defined as PaO2<7.0kPa and/or PaCO2>9kPa
3. Failure to tolerate NIV during initiation or if required to treat acute decompensation
4. Prior acute hypercapnic respiratory failure requiring intubation
5. Hypercapnic respiratory failure secondary to an identifiable cause other than obesity
6. Unstable coronary artery syndrome
7. Cognitive impairment that would prevent informed consent into the trial and/or inability to comply with the protocol
8. Psychiatric disease necessitating anti-psychotic medication, ongoing treatment for drug or alcohol addiction, persons of no fixed abode post-discharge
9. Patients undergoing renal replacement therapy
10. Patients with co-existent cancer and a prognosis likely to be less than 12-months
11. Critical peripheral vascular disease awaiting re-vascularisation procedure (or claudication distance <100 metres)
12. Stroke with hemiparesis
13. Age <18 years
14. Pregnant

Recruitment start date


Recruitment end date



Countries of recruitment

France, Switzerland, United Kingdom

Trial participating centre

St Thomas's Hospital
United Kingdom

Trial participating centre

St James' Hospital
United Kingdom

Trial participating centre

Royal Brompton Hospital
United Kingdom

Trial participating centre

Royal Free Hospital
United Kingdom

Trial participating centre

University Hospital of Grenoble

Trial participating centre

University Hospital of Rouen

Sponsor information


Guy's and St. Thomas' NHS Foundation Trust (UK)

Sponsor details

Department of Immunology
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Philips Respironics Inc (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Plan publication in a high-impact peer reviewed journal in April 2019.

IPD sharing statement
The datasets generated and/or analysed during the current study will be included in the subsequent results publication.

Intention to publish date


Participant level data


Basic results (scientific)

Publication list

2015 protocol in:

Publication citations

Additional files

Editorial Notes

10/02/2020: The following changes have been made: 1.The ethics approval has been updated. 2. The IRAS number has been added. 12/05/2017: Switzerland was removed from the countries of recruitment. 04/04/2017: The overall trial end date was changed from 01/04/2016 to 30/04/2018.