This prospective stepped-wedge study evaluates whether use of the Breathlessness diagnostics in a Box (BiaB) tool shortens the time to diagnosis in patients presenting with breathlessness, compared with usual care. The study is conducted in general practice settings in the Netherlands, Spain, and Portugal. Participating sites start with a usual care period and transition sequentially to the BiaB intervention period. Data are collected during routine clinical visits, from electronic medical records, and through questionnaires completed by patients and healthcare professionals.

This is a prospective interventional study using a stepped-wedge cluster design with a usual care period followed by an intervention period. Participating general practice sites are assigned to one of five predefined sequences determining the timing of transition from usual care to the BiaB intervention. All sites start in the usual care phase and sequentially transition to the intervention phase according to the study schedule.

The primary objective of the study is to assess whether use of BiaB shortens the time to diagnosis in patients presenting with breathlessness, compared with usual care without BiaB. Secondary objectives include evaluating whether BiaB increases the number of new diagnoses of chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD), and assessing the usability and efficiency of the BiaB tool.

The study is conducted in general practice settings in the Netherlands, Spain, and Portugal, with a total of 45 sites. Each site participates for a total duration of 40 weeks. Patients attend a single study visit and may complete up to four quarterly questionnaires over a maximum follow-up of one year. Data are collected during routine clinical care, from electronic medical records, and via questionnaires completed by patients and healthcare professionals. Data from the usual care period, and where available retrospective data, are used as control data for comparison with the intervention period.

The study aims to capture the real-world heterogeneity in primary care practices and patients. Therefore, inclusion and exclusion criteria are limited.

Inclusion criteria

• Patient must be at least 18 years old at the time of signing the informed consent.
• Patients that present with undiagnosed dyspnea (breathlessness); or Patients who have existing diseases that could cause breathlessness, but have residual or increasing breathlessness that could be caused by other not yet detected diseases. Or HCP has doubts or requires additional tests to confirm diagnosis or to suspect new, parallel, diagnoses. For example, breathlessness in patients assessed within the framework of Cardiovascular Risk Management or for COPD monitoring

Exclusion criteria

1. Acute worsening of previous diagnosed chronic disease where there is no suspicion of comorbidities (for example when a patient with clear COPD diagnosis has an exacerbation where typically the HCP will not perform additional tests).
2. Inability to understand and sign the written consent form.