Comparison of performance of four instruments in evaluating the effects of salmeterol on asthma quality of life.

Quality of life measures are increasingly used as important efficacy endpoints in studies of drugs for asthma. The purpose of this study was to assess both the sensitivity to change and the construct validity of four different quality of life instruments in patients with asthma. In a double-blind, parallel group study, 120 moderate asthma patients, aged between 18-70 yrs, received either inhaled salmeterol 50 micrograms b.