TABLE 1

Study definitions: database-derived outcome measures and matching criteria

Primary end-point
 Risk-domain asthma control includes all of the following:
  1. No asthma-related# hospital attendance or admission, ED attendance, out-of-hours attendance, or outpatient hospital attendance, and
  2. No GP consultation for lower respiratory tract infection with resultant antibiotic prescription, and
  3. No prescription for acute course of oral corticosteroids
Secondary end-points
 Number of severe exacerbations+, defined as any of the following [31]:
  1. Asthma-related# hospital attendance or admission or ED attendance, or
  2. Acute course of oral corticosteroids
 Number of acute respiratory events, defined as any of the following:
  1. Asthma-related# hospital attendance or admission or ED attendance, or
  2. Acute course of oral corticosteroids, or
  3. GP consultation for lower respiratory tract infection
 Treatment stability, includes all of the following:
  1. Asthma control (primary end-point, see above) and
  2. No treatment change, defined additional therapy or change in therapy as
    a) Increased ICS dose (by ≥50%), or
    b) Use of additional therapy, such as LABA, LTRA or theophylline
 Matching criteria: patients were matched at the index prescription date by
  1. Sex (male/female)
  2. Age (±5 years)
  3. Last ICS daily dose prescribed before index date prescription (categorised as 1–50 μg/51–100 μg/101–200 μg/201–300 μg/301–400 μg/>400 μg in extrafine beclomethasone equivalents§)
  4. Asthma control (defined as primary end-point) during baseline year (controlled/not controlled)
  5. Mean SABA daily dose during baseline yearƒ (categorised as 0 μg/1–200 μg/201–400 μg/>400 μg)
  6. Asthma consultation(s) without severe exacerbation (0/1/≥2)

  • ED: emergency department; GP: general practitioner; ICS: inhaled corticosteroid; LABA: long-acting β2-agonist; LTRA: leukotriene receptor antagonist; SABA: short-acting β2-agonist. #: defined as all events with a lower respiratory code, including all asthma codes and lower respiratory tract infection codes; : identified as GP consultations with a code for lower respiratory tract infection Read code in the database; +: hospital attendance/admission and/or an oral corticosteroid course within a 2-week window were considered as one exacerbation; §: doses of budesonide and the large-particle beclomethasone (Clenil Modulite, Chiesi, Manchester, UK) were halved, and fluticasone doses of 250 μg and 500 μg were treated as equivalent to extrafine-particle beclomethasone 200 and 400 μg; ƒ: SABA daily dose was defined as total prescribed SABA during baseline year divided by 365. Reproduced from [19] with permission from the publisher.