The BTS/SIGN guidelines, widely seen as the gold standard for asthma, emphasises that no single test can be used to definitively diagnose asthma.
It instead advocates that GPs undertake a ‘structured clinical assessment’ using a combination of patient history, examination and tests to assess the probability of asthma.
It comes after NICE postponed its own guidance on asthma diagnosis to allow for the feasibility of its 'radical' recommendations to be tested.
NICE release the draft version of the guidance 21 months ago in January 2015, which laid out a standardised method of diagnosing the condition using spirometry and FeNO testing.
The BTS/SIGN guideline also recommends spirometry as the key frontline breathing test 'to be performed in most situations with adults and children over five years of age'.
But it adds that a normal spirometry result does not always exclude an asthma diagnosis, especially if the patient is not experiencing symptoms at the time. It therefore recommends repeating the test while the patient is experiencing symptoms, using different tests and observing the patient over time to confirm diagnosis.
Patients should be stratified into three groups based on the probability of them having asthma – high, medium or low, it recommends. Each group then has its own set of key treatment and management actions.
The guideline recommends giving all patients a written asthma action plan, and highlights short acting beta2 antagonists as the 'key rescue therapy' from asthma attack symptoms.
Respiratory physician Dr John White, who co-chaired the group behind the guideline, said: ‘Asthma is a complex disease and symptoms can vary over time. In addition, evidence shows there’s still no single "magic bullet test" for asthma. This all means that diagnosis isn’t always easy.
‘This update should be really valuable as it gives healthcare professionals an evidence-based but highly practical approach to suspecting and confirming a diagnosis of asthma, as well as giving the latest guidance on the most appropriate treatments and interventions to combat the disease.
‘The guideline also reinforces previous messages that remain vital in the battle against asthma. It is critical, for example, that everyone with the condition is offered a written personalised action plan and review, and that inhalers are only prescribed after patients have received training in using them and demonstrate adequate technique.’