Finger Versus Earlobe Pulse Oximetry During the 6-Minute Walk Test in Interstitial Lung Disease

NCT07723872 | Recruiting

• 1 other identifier: OXISITE-ILD
• Study Type: observational
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

The OXISITE-ILD study is a prospective, multicenter, observational study designed to evaluate the agreement between finger (digital) and earlobe (auricular) pulse oximetry for measuring oxygen saturation (SpO2) during the six-minute walk test (6MWT) in patients with interstitial lung disease (ILD). In routine clinical practice, exercise SpO2 is usually measured at the finger; however, the finger reading can be unreliable in some patients, and there is currently no recommendation on the best sensor location in ILD. This study compares the two sensor locations, recorded at the same time, and evaluates whether any disagreement changes how exercise desaturation is classified and whether ambulatory oxygen is indicated. All patients undergoing a 6MWT as part of routine ILD care are included consecutively to ensure a pragmatic, real-world representation of the ILD population. The primary objective is to measure the agreement between the two locations in the lowest SpO2 reached during the test, including the size and direction of any difference. Secondary objectives include the reclassification of patients at the clinical desaturation thresholds, the comparison between autoimmune and non-autoimmune ILD, the rate of invalid readings at each location, and the clinical, vascular and functional factors associated with disagreement.

Conditions

Interstitial Lung Disease (ILD); Idiopathic Pulmonary Fibrosis (IPF); Progressive Pulmonary Fibrosis; Connective Tissue Disease-Associated Interstitial Lung Disease; Interstitial Lung Disease Due to Connective Tissue Disease (Disorder)

Keywords

Pulse Oximetry; Earlobe Oximetry; Finger Oximetry; Oxygen Saturation; SpO2; Six-Minute Walk Test; Exercise Desaturation; Ambulatory Oxygen; Interstitial Lung Disease; Idiopathic Pulmonary Fibrosis; Connective Tissue Disease-ILD; Systemic Sclerosis; Method Comparison; Bland-Altman Analysis

Outcome Measures

Primary Outcomes (2)

• Intraclass correlation coefficient for agreement in minimum SpO2 between sensor locations

  Absolute agreement in minimum SpO2 during the six-minute walk test between the finger and earlobe sensors, quantified with the intraclass correlation coefficient (two-way mixed-effects model, absolute agreement) and its 95% confidence interval. ICC values are interpreted as below 0.50 poor, 0.50 to 0.75 moderate, 0.75 to 0.90 good, and above 0.90 excellent agreement.

  Day 1

• Bland-Altman agreement in minimum SpO2 between sensor locations

  Agreement in minimum SpO2 during the six-minute walk test between the finger and earlobe sensors, assessed with Bland-Altman analysis: mean bias (earlobe minus finger) with its 95% confidence interval and 95% limits of agreement, evaluated against a prespecified clinically acceptable difference of 3 percentage points. The direction of the bias is reported, as the finger is hypothesised to register lower values than the earlobe.

  Day 1

Secondary Outcomes (6)

• Reclassification of exertional desaturation between sensor locations at SpO2 below 88%

  Day 1

• Reclassification of exertional desaturation between sensor locations at SpO2 below 90%

  Day 1

• Reclassification of exertional desaturation between sensor locations at a fall in SpO2 of 4% or more

  Day 1

• Agreement in minimum SpO2 by autoimmune versus non-autoimmune ILD

  Day 1

• Rate of invalid or poor-quality readings by sensor location

  Day 1

Other Outcomes (4)

• Agreement in SpO2 at additional timepoints

  Day 1

• Quantitative paired difference and Passing-Bablok regression between sensor locations

  Day 1

• Agreement of each sensor location with baseline arterial oxygen saturation

  Day 1

Study Arms (1)

ILD patients undergoing the 6MWT

Adults with an established diagnosis of interstitial lung disease (ILD) undergoing a six-minute walk test (6MWT) as part of routine care. Each participant is assessed once, with oxygen saturation (SpO2) and heart rate recorded simultaneously at the finger and at the earlobe. Pre-specified subgroups for the analysis are autoimmune-associated versus non-autoimmune ILD.

Other: Dual-site pulse oximetry (finger and earlobe)

Interventions

Dual-site pulse oximetry (finger and earlobe) OTHER

During a single 6MWT, SpO2 and heart rate are recorded simultaneously at the finger (digital) and the earlobe (auricular) with two pulse oximeters, at eight timepoints (baseline, minutes 1 to 6, and a 2-minute recovery). No treatment is administered and routine clinical management is not modified; the procedure adds the simultaneous earlobe measurement for comparison with the finger.

ILD patients undergoing the 6MWT

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Consecutive adults with a confirmed diagnosis of interstitial lung disease (ILD), either newly diagnosed or under follow-up, attending the ILD/pulmonary fibrosis units of the participating centres and undergoing a clinically indicated 6-minute walk test. Patients with or without prior oxygen therapy are enrolled consecutively, and baseline oxygen status (none, exertional only, or at rest) is recorded. Each patient is assessed on a single occasion, consistent with the cross-sectional design.

You may qualify if:

• Adults aged 18 years or older
• Confirmed diagnosis of interstitial lung disease (ILD) based on clinical, radiological and/or histological criteria
• Newly diagnosed or under follow-up for ILD
• Physically and cognitively able to perform the 6-minute walk test (6MWT)
• Signed informed consent

You may not qualify if:

• Inability to obtain a reliable, stable baseline pulse oximetry reading at the finger and/or the earlobe, preventing a valid paired baseline measurement and the calculation of agreement
• ILD exacerbation, decompensated comorbidity, or acute respiratory infection at the time of the test

Sponsors & Collaborators

• Hospital de Granollers: lead

Study Sites (1)

Hospital de Granollers

Granollers, Spain, 08402, Spain

RECRUITING

MeSH Terms

Conditions

Lung Diseases, Interstitial; Idiopathic Pulmonary Fibrosis; Scleroderma, Systemic

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases; Pulmonary Fibrosis; Connective Tissue Diseases; Skin and Connective Tissue Diseases; Skin Diseases

Study Officials

• Jaume Bordas-Martinez, M.D., Ph.D.

  Hospital de Granollers

  STUDY DIRECTOR

Central Study Contacts

Jaume Bordas-Martinez, Ph.D.; M.D.

CONTACT

938 42 50 00; jbordas@fphag.org

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Coordinator of Interstitial Lung Disease Unit

Study Record Dates

• First Submitted: June 30, 2026
• First Posted: July 23, 2026
• Study Start: January 13, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: July 23, 2026

Record last verified: 2026-07

Locations

ES (1)