Predictors of asthma control in everyday clinical practice in Switzerland.
OBJECTIVE
To identify predictors of improved asthma control under conditions of everyday practice in Switzerland.


METHODS
A subgroup of 1380 patients with initially inadequately controlled asthma was defined from a cohort of 1893 asthmatic patients (mean age 45.3 + or - 19.2 years) recruited by 281 office-based physicians who participated in a previously-conducted asthma control survey in Switzerland. Multiple regression techniques were used to identify predictors of improved asthma control, defined as an absolute decrease of 0.5 points or more in the Asthma Control Questionnaire between the baseline (V1) and follow-up visit (V2).


RESULTS
Asthma control between V1 and V2 improved in 85.7%. Add-on treatment with montelukast was reported in 82.9% of the patients. Patients with worse asthma control at V1 and patients with good self-reported adherence to therapy had significantly higher chances of improved asthma control (OR = 1.24 and 1.73, 95% CI 1.18-1.29 and 1.20-2.50, respectively). Compared to adding montelukast and continuing the same inhaled corticosteroid/fixed combination (ICS/FC) dose, the addition of montelukast to an increased ICS/FC dose yielded a 4 times higher chance of improved asthma control (OR = 3.84, 95% CI 1.58-9.29). Significantly, withholding montelukast halved the probability of achieving improved asthma control (OR = 0.51, 95% CI = 0.33-078). The probability of improved asthma control was almost 5 times lower among patients in whom FEV(1) was measured compared to those in whom it was not (OR = 0.23, 95% CI = 0.09-0.55). Patients with severe persistent asthma also had a significantly lower probability of improved control (OR = 0.15, 95% CI = 0.07-0.32), as did older patients (OR = 0.98, 95% CI = 0.97-0.99). Subgroup analyses which excluded patients whose asthma may have been misdiagnosed and might in reality have been chronic obstructive pulmonary disease (COPD) showed comparable results.


CONCLUSIONS
Under conditions of everyday clinical practice, the addition of montelukast to ICS/FC and good adherence to therapy increased the likelihood of achieving better asthma control at the follow-up visit, while older age and more severe asthma significantly decreased it.
Taegtmeyer
Anne B
AB
Medical Outpatient Clinic and Department of Internal Medicine, University Hospital Basel, Switzerland.
Steurer-Stey
C
C
Price
David B
DB
Wildhaber
J H
JH
Spertini
F
F
Leuppi
Jörg D
JD
D000085:Acetates / Q000627:therapeutic use*; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000517:prevention & control*; D015331:Cohort Studies; D003521:Cyclopropanes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011804:Quinolines / Q000627:therapeutic use*; D013440:Sulfides; D013557:Switzerland
D000085:Acetates; D018927:Anti-Asthmatic Agents; D003521:Cyclopropanes; D011804:Quinolines; D013440:Sulfides; C093875:montelukast