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Use spirometry and FeNO to diagnose asthma, says NICE

GPs and practice nurses should now carry out objective tests such as spirometry and forced exhaled nitric oxide (FeNO) to diagnose asthma, NICE has recommended.

NICE has recommended spirometry and FeNO testing alongside clinical assessment of symptoms in order to make asthma diagnosis more accurate and treatment more effective.

The new guideline, covering diagnosis, management and monitoring of chronic asthma, was published this week after being delayed for a second time at the end of October to allow discussions with NHS England over implementation.

The guideline recommends objective testing such as spirometry and FeNO for making a diagnosis of asthma and cautions that nurses and doctors should not rely on symptoms without objective tests to make the diagnosis – bypassing the gold-standard BTS/SIGN recommendation to confirm a diagnosis based on a trial of treatment.

It also recommends that if patients cannot perform a particular objective test, you should try at least two other tests and make the diagnosis based on symptoms and any positive test results.

The draft recommendations were met with fierce criticism from the Primary Care Respiratory Society (PCRS), the BMA and the RCGP in 2015 on the basis that the objective tests were too expensive and costly to carry out in primary care, warning that asking primary care staff to adhere to the new diagnostic algorithm would lead to increased appointments, referrals and costs.

NICE took the unprecedented step of delaying publication of the guidelines in September 2015 due to the challenges identified in implementing the guidelines. They carried out pilot studies to test the feasibility of putting the guidelines in to practice, and the guidelines were consulted on again earlier this year after the studies showed that the new objective tests were time consuming and did not necessarily improve the accuracy of diagnosis.

The new guideline also diverges from the BTS/SIGN recommendation to offer a long-acting beta agonist (LABA) as the first-line add-on therapy for patients whose asthma is not controlled on inhaled corticosteroids alone.

Instead, NICE recommends adding an LTRA tablet to inhaled corticosteroid treatment before trying a LABA, as they are cheaper and therefore more cost-effective.

Respiratory experts voiced their concerns over the addition of LTRAs to the guideline earlier this year, saying that patients may neglect their inhalers in favour of taking the tablet, leading to poor outcomes and potentially costing lives.

NICE recognises the challenges involved in putting the guideline in to practice, saying significant changes to practice will be needed but that changes that can be made should be implemented as soon as possible.

The guideline says: 'NICE is recommending objective testing with spirometry and FeNO for most people with suspected asthma. This is a significant enhancement to current practice, which will take the NHS some time to implement, with additional infrastructure and training needed in primary care. New models of care, being developed locally, could offer the opportunity to implement these recommendations.

'The investment and training required to implement the new guidance will take time. In the meantime, primary care services should implement what they can of the new guidelines, using currently available approaches to diagnosis until the infrastructure for objective testing is in place.’

But the PCRS have claimed that the guideline will create ‘uncertainty’ for those in primary care due to the differences between the NICE and BTS/SIGN guidelines.

They said: ‘We have significant concerns about an approach that recommends greater reliance on objective testing at a single point in time. This risks not detecting asthma if the patient is asymptomatic at the time of testing.

‘We see a role for FeNO testing, where the structured clinical assessment suggests an intermediate probability, in line with BTS/SIGN guidance. But we are concerned that NICE’s recommendation to use FeNO testing in all people with suspected asthma as a primary investigation raises major implementation challenges and could have a number of unintended consequences. FeNO testing is not widely available in primary care. It carries significant cost - both in terms of initial investment and the ongoing cost of consumables. It is therefore unlikely to be a viable option for all practices, but may be more realistically provided as part of a locality based diagnostic service.  

They added that the perceived ‘mandatory’ nature of FeNO testing may increase referrals to secondary care, ‘deskilling’ those in primary care.

‘We do not see the the widespread implementation of FENO testing as high priority for localities to address. We recommend peak flow monitoring as the initial objective test, with a role for FeNO as per the BTS/SIGN guidelines,’ they said.