Performance of the Asthma Impact on Quality of Life Scale (A-IQOLS) in diverse asthma research populations and demographic subgroups.

Background: The Asthma Impact on Quality of Life Scale (A-IQOLS) assesses the patient-perceived negative effect of asthma on quality of life. Its standard error of measurement is known; it has strong construct, convergent, and divergent validity; and it provides information that is unique among asthma outcome measures.

Objective: We sought to characterize the psychometric properties of the A-IQOLS and its suitability for use in demographically and clinically diverse adult asthmatic populations.

A new measure to assess asthma's effect on quality of life from the patient's perspective.

Background: The Asthma Impact on Quality of Life Scale (A-IQOLS) assesses the negative effect of asthma on quality of life (QoL) from the patient's perspective by using dimensions of Flanagan's Quality of Life Scale (QOLS), a measure of current QoL.

Objectives: We sought to determine and compare the psychometric properties of the A-IQOLS and QOLS, including their sensitivities to differences and change in asthma status.

Methods: In a test-retest design (3- to 5-week interval) adults with persistent asthma underwent spirometry and were administered the A-IQOLS, other asthma outcome measures (Asthma Control Test, Asthma Symptom Utility Index, and the Marks and Juniper Asthma Quality of Life Questionnaires), and the QOLS.