IMPACT OF THE GLOBAL ON PATIENT PERCEIVABLE CHANGE IN AN ASTHMA SPECIFIC QOL QUESTIONNAIRE

One method of defining clinically meaningful changes in quality of lif e domain scores is 'anchoring', that is, relating changes in domain sc ores to more easily understood changes on a global question. Although this methodology has been used to assess changes in domain scores in c linical trials, the choice of global question has not undergone much s crutiny. This study examines the impact of two global questions on the definition of clinically meaningful changes in an asthma specific qua lity of life (ASQOL) questionnaire. We tracked 343 patients with mild to moderate asthma symptoms in a placebo controlled clinical trial. Th e patients responded to the ASQOL questionnaire, and answered two glob al questions; one assessing how well their asthma is controlled, and t he other assessing the change in their asthma since the start of the s tudy. Changes in each domain of the ASQOL questionnaire were related t o each global question. Since each global question led to different de finitions of what constituted meaningful change, we concluded that the wording of the global question can affect the definition of meaningfu l change in the ASQOL domain scores. Thus, when identifying meaningful changes, it is important to state the global question so that the con text of the meaningful change is correctly understood.