One in twenty people with asthma has severe asthma, where symptoms do not improve even when the usual medications are used correctly. Bronchial thermoplasty is a new treatment for this condition. Safety data for this procedure comes mostly from clinical trials, but this research used data from routine UK clinical practice to evaluate its safety in the real world.

Why was this work needed?

Bronchial thermoplasty is a treatment for severe asthma. It helps to stop the airways from constricting and reduce severity of attacks by using radiofrequency energy to apply heat to the muscle inside airways. This is a new treatment and, although its safety has been studied in clinical trials there is a need to confirm this with data from routine clinical practice and monitor the long term impact.

The procedure was not approved by the National Institute for Health and Care Excellence (NICE), but because it had showed promise, specialist centres were allowed to carry out the procedure to gather additional information to assess whether it should be made available more widely.

What happened?

The researchers gathered data from the records of people receiving bronchial thermoplasty and assessed the incidence of hospital complications in hospital and the need for emergency readmission to hospital or admission to A&E, for breathing problems, for the 30 days following the procedure. They then compared the results with the clinical trials and found that although there were more adverse events seen in routine clinical practice compared with trials involving less severe asthma patients, there was a similar rate of adverse events compared with one trial which included severe asthma patients. The study showed that the procedure appeared to be as safe in routine clinical practice after adjustment for underlying disease severity.

What were the benefits?

The difference between results from the clinical setting of trials and the real world shows the importance of using data from routine clinical practice to study new developments beyond clinical trials. The researchers also found that the people they were studying had more severe asthma than those involved in two of the clinical trials, which might explain the difference.

This research is part of the ongoing process to fully understand the safety and efficacy of this new treatment.

What type of data was involved?

The researchers used data from the British Thoracic Society (BTS) UK Difficult Asthma Registry (DAR) and the Hospital Episode Statistics (HES) database. The two databases are independent of each other and the researchers only included people whose records appeared in both databases.

The HES data used was de-personalised and data collection in DAR had fully informed patient consent and Research Ethics approval.

Who funded and collaborated on this work?

This work was carried out by the UK National Institute for Health and Care Excellence (NICE) External Assessment Centre based at The Newcastle upon Tyne Hospitals NHS Foundation Trust and York Health Economics Consortium in collaboration with the BTS Severe Asthma Network and NICE.

Where can I go for more information?

Procedural and short-term safety of bronchial thermoplasty in clinical practice: evidence from a national registry and Hospital Episode Statistics (Journal of Asthma, 2016)