Asthma treatment preference study: a conjoint analysis of preferred drug treatments.

OBJECTIVE Assessment of patient preferences for attributes of asthma treatments. METHODS Two hundred ninety-eight patients (age range, 18 to 60 years) from 15 centers in Sweden completed a questionnaire concerning their asthma, and ranked 18 alternative treatments using conjoint analysis. Patients were receiving treatment with either inhaled corticosteroids (ICS) and short-acting bronchodilator (n = 123) or ICS and long-acting bronchodilator (separate inhalers, n = 87; combination inhaler, n = 88). Attributes analyzed were maintenance treatment, additional reliever, time to onset and duration of reliever, number of symptom-free days (SFDs) per month, and out-of-pocket cost per month. RESULTS Conjoint analysis showed that the most important aspect of treatment was SFD. Forty percent of the patients had <or= 15 SFDs per month. Eighty-five percent of the patients preferred another treatment over their current treatment. Treatment preferences were heterogeneous, and in 78% were not covered by current treatment guidelines. A total of 148 patients (50%) preferred a combination inhaler to separate inhalers, and 233 patients (78%) preferred a reliever that is both rapid and long acting. The most preferred treatment was a combination inhaler for maintenance and reliever use. On average, the patients were willing to pay an additional 328 Swedish krona [36 US dollars] per month for the change to the preferred treatment. CONCLUSION SFDs were the most important attribute in asthma treatment. Patients were willing to pay for a switch to their preferred treatment. The most favored treatments were a reliever therapy that is both rapid and long acting and a combination inhaler for both maintenance and as-needed use.