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Post-hoc analyse START

Should recommendations about starting inhaled corticosteroid treatment for mild asthma be based on symptom frequency: a post-hoc efficacy analysis of the START study

Helen K Reddel, William W Busse, Søren Pedersen, Wan C Tan, Yu-Zhi Chen, Carin Jorup, Dan Lythgoe, Paul M O’Byrne et al. Lancet 2017; 389: 157–66

Background:
  • Conventionally, ICS treatment is recommended for patients with symptoms on more than 2 days per week, but this criterion has scant evidence.
  • It is unclear whether patients with less frequent asthma symptoms benefit from ICS treatment, or whether there is evidence to support the present symptom-based criteria for initiating ICS. 
  • This study is the first to assess the validity of the previous symptom-based cut-off for starting ICS by assessing the effects of budesonide versus placebo for severe asthma exacerbations, lung function, and asthma symptom control in patients with different symptoms frequency.
Methods:
  • Post-hoc analysis of the 3-year inhaled Steroid Treatment As Regular Therapy (START) study conducted in 32 countries.
  • 7138 mild asthma patients randomised to receive once daily inhaled budesonide (400 µg or 200 µg if aged <11 years) or placebo.
  • Coprimary outcomes: time to first severe asthma-related event (SARE; hospital admission, emergency treatment, or death) and change from baseline in lung function after bronchodilator.
  • Key exclusion criteria: Asthma symptoms or treatment for more than 2 years before enrolment, more than 30 days of treatment per year with a corticosteroid, prebronchodilator FEV1 of less than 60% predicted, postbronchodilator FEV1 of less than 80% predicted.
  • Interaction with baseline symptom frequency was investigated:
    • Group of patients 1: 0 to 1 symptom days per week (31%)
    • Group of patients 2: >1 to ≤2 symptom days per week (27%)
    • Group of patients 3: >2 symptom days per week (43%)
Results:

Across all 3 symptoms frequency groups and irrespective of baseline symptom frequency:

  • Time to first severe asthma-related event (SARE) was prolonged

 

  • Decline in postbronchodilator lung function at 3 years’ follow-up was reduced
  • Severe exacerbations requiring oral or systemic corticosteroids were reduced
 
  • Symptom-free days were increased   
    Similar results were noted when participants were classified by any guidelines criterion as so-called persistent versus so-called intermittent asthma.
Conclusion:
  • These findings challenge long-standing recommendations that asthma should be treated with SABA alone if the patient has symptoms ≤2 days per week.
  • But mild symptomatic patients might be more mindful of their (infrequent) symptoms than the remote risk of an exacerbation and be poorly adherent to a daily ICS treatment.
  • An alternative risk-reduction strategy, with as-needed ICS intake driven by concomitant β2-agonist for symptom relief, is already of substantial interest, would also address concern about side-effects, could address poor adherence as well, and might be more acceptable to clinicians and patients for mild asthma than regular daily ICS.


Reference:

Helen K Reddel, William W Busse, Søren Pedersen, Wan C Tan, Yu-Zhi Chen, Carin Jorup, Dan Lythgoe, Paul M O’Byrne et al. Lancet 2017; 389: 157–66

NS ID XL-0397-RD07/2018-LB Local code 688