Development and validation of the Asthma Life Impact Scale (ALIS).
BACKGROUND
Current asthma patient-reported outcome (PRO) measures focus on symptoms and functioning and may not capture the holistic impact of asthma on the quality of life of the patient.


OBJECTIVE
To develop a PRO measure capturing the overall impact of asthma on patient's quality of life.


METHODS
Items for the Asthma Life Impact Scale (ALIS) were generated from patients with asthma during interviews in the UK and focus groups in the US. The ALIS was tested with UK and US asthma patients during cognitive debriefing interviews and included in large, two-administration, validation studies in the UK and US.


RESULTS
Issues raised by asthma patients during interviews (n = 39 patients) and focus groups (n = 16 patients) were included in the draft ALIS. Cognitive debriefing interviews with 29 UK and US asthma patients showed that the scale was relevant and comprehensive. 140 UK and 185 US asthma patients participated in the validation study. The analysis showed that the ALIS measures a single construct, namely the overall impact of asthma on patients' quality of life. Internal consistency (Cronbach's Alpha) was high (UK = 0.94; US = 0.92) as was test-retest reliability (UK = 0.93; US = 0.83). Patients reporting worse general health or more severe asthma had significantly higher ALIS scores (p < 0.001) (indicating greater negative impact of asthma). Correlations with the Asthma Quality of Life Questionnaire were moderate to high.


CONCLUSIONS
The final 22-item ALIS is unidimensional, reliable and valid, and a valuable tool for comprehensively assessing the holistic impact of asthma from the patient's perspective.
Meads
David M
DM
Galen Research Ltd, Manchester, United Kingdom. david_meads@hotmail.com
McKenna
Stephen P
SP
Doward
Lynda C
LC
Pokrzywinski
Robin
R
Revicki
Dennis
D
Hunter
Cameron
C
Glendenning
G Alastair
GA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001249:Asthma / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D017144:Focus Groups; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D017060:Patient Satisfaction; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D018434:Sickness Impact Profile; D016896:Treatment Outcome; D006113:United Kingdom; D014481:United States / Q000453:epidemiology; D055815:Young Adult