An observational study in Asthma, COPD and Small Airway Disease, sponsored by General Practitioners Research Institute. Active, not recruiting at 1 site in Netherlands. Open to participants aged 35 Years and older. Per ClinicalTrials.gov, last updated 2026-01-28.
Sponsored by General Practitioners Research Institute · Observational
Rationale: The Small Airways are a major site of obstruction in many respiratory diseases, including COPD. More insight into a diagnosis of Small Airways Dysfunction (SAD) in patients with COPD is clinically valuable as it might enable tailored pharmacotherapy. Currently, methods to diagnose SAD in COPD are not standardized and are not available in routine clinical practice. The Small Airways Dysfunction Tool (SADT) was developed to identify patients with asthma and SAD. Initially, the SADT included a comprehensive 63-item questionnaire. The number of items has been reduced to a SADT-asthma (SADT a) questionnaire and key patient and disease characteristics for it to be feasible and implementable in clinical practice. Although there are many similarities between asthma and COPD, there might be differences in clinical characteristics and responses to small airways dysfunction between the two diseases. The current study aims to adapt the original 63-item SADT questionnaire for dedicated use in COPD by reducing the number of items, and identifying COPD-SAD-specific items, to enhance its efficiency in identifying SAD when combined with key patient and disease characteristics in individuals with COPD (SADT-c). In addition, a comparison of diagnostic accuracy of spirometry and oscillometry will be made by interpretations by a panel of experts to provide a triage diagnosis. The previously developed machine learning AC/DC tool will be used to explore its diagnostic accuracy using oscillometry and spirometry results. This can contribute to standardizing oscillometry in clinical practice.
3,921 studies on the registry are indexed under Asthma; 507 are open to participants now.
This study's enrollment of 108 is below the median of 150 across 970 observational studies indexed under Asthma.
Browse Asthma studies →General Practitioners Research Institute is the lead sponsor of 11 studies on the registry; 1 is open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population for the SCOOP study will consist of patients referred by their General Practitioner (GP) to the Asthma/COPD service. Patients can be referred by their GP when they are suspected to have asthma, Chronic Obstructive Pulmonary Disease (COPD), asthma-COPD overlap (ACO) or when they present with pulmonary symptoms of unknown origin. After referral by the GP, patients will be invited by the Asthma/COPD service. Both patients invited for an initial diagnostic visit or a control visit can participate in the SCOOP study.
Exclusion Criteria:
Diagnostic Test: Oscillometer ALDS
Diagnostic Test: Oscillometer ALDS
Oscillometry is a non-invasive technique for assessing lung function, as it requires only 45-60 seconds of tidal breathing to measure the mechanical properties of the respiratory system. This makes the measurement suitable for patients of all ages and with severe respiratory conditions. It also reduces the number of errors as compared to other methods (e.g., spirometry). Oscillometry can be used to evaluate airway resistance, reactance, and compliance, insights that are challenging to obtain with other methods. This quality makes oscillometry especially sensitive for obstructive diseases like asthma and COPD, and correlations with physiological small airways dysfunction have also been shown . The Ambulatory Lung Diagnosis System (ALDS), manufactured by Lothar MedTec, can be used to perform oscillometry and spirometry. The ALDS follows the European Respiratory Society (ERS) technical standards for measurement and reporting of oscillometry.
The predictive value of SADT-c for detecting SAD in patients with COPD.
To determine whether SADT-c can be used in patients with COPD to detect SAD.
Time frame: At baseline study visit, during pulmonary function testing
Predictive value of SADT-a bronze model for SAD in COPD.
To determine whether the bronze model SADT-a is predictive for SAD in COPD.
Time frame: At baseline study visit, during pulmonary function testing
Develop SADT-c.
Agreement between SADT-c results and disease parameters.
Time frame: At baseline study visit, using data collected during pulmonary function testing and clinical assessment
To evaluate how SADT-c compares to SADT-a.
Relative predictive value of SADT-a versus SADT-c for SAD in COPD defined as R5-R20 \> ULN1
Time frame: At baseline study visit, during pulmonary function testing
To determine whether oscillometry and spirometry are equally effective for triage diagnosis in patients in primary care with respiratory symptoms.
Agreement between triage diagnoses from oscillometry and spirometry. Relative usability of spirometry and oscillometry.
Time frame: At baseline study visit, during initial diagnostic assessment in primary care
Assess the diagnostic performance of the Asthma/COPD Differentiation Classification (AC/DC) Tool.
Diagnostic performance of AC/DC tool compared to expert panel diagnosis.
Time frame: At baseline study visit, with expert panel diagnosis based on data collected during the study assessment
Plan to share: No
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
General Practitioners Research Institute