Phase four: Psychometric analysis (Reliability and Validity).
The reliability, criterion (concurrent and convergent validity),
construct validity, sensitivity, and specificity were assessed in this
phase. The final version of the developed questionnaire was made
available to another set of participants with asthma. To be included in
this phase of the study, participants should be diagnosed with asthma by
a specialist, prescribed regular inhaled corticosteroid inhalers for the
last six months at least, and above the age of 18. The participants were
asked about these inclusion criteria at the beginning of the
questionnaire and were noted to only complete the questionnaire if they
met these inclusion criteria. Participants were targeted through emails
and social media (Facebook and WhatsApp).
Demographic information (gender, age, living place, marital status,
education, employment, and smoking) were requested from the participants
(22). All the questionnaires used in this phase (AAMQ-13, TAI, ACT, and
PHBS) were translated from English to Arabic by qualified experts with
many years of experience in translation. These experts were native
speakers of the target language; they had a comprehensive knowledge of
the relevant terminology and used a professional-related website in
translation to ensure the accuracy of the terminologies used (27).
Afterward, the translation was validated by colleagues (n= 2) who were
experts in the clinical research field and in language translation.
Their comments and feedback provided were considered by the research
team and then incorporated where appropriate.
The reliability was assessed through the Cronbach’s alpha coefficient.
The construct validity was assessed through AAMQ-13 factor analysis. The
criterion-concurrent validity was assessed through subjectivemeasure (comparing the AAMQ-13 to the Test of the Adherence to Inhaler
(TAI)) (28). The TAI is a validated 10-item questionnaire used to assess
the adherence to inhalers in patients with asthma or COPD. It has a
score range from 10 to 50 (each item has a score from 1 to 5, where 1
represents the worst possible score and 5 represents the best possible
score). The cut-offs for TAI were 50 for adherent patients, 46-49 for
intermediate adherent patients, and ≤ 45 for non-adherent patients (28).
The criterion-convergent validity was assessed through comparing the
AAMQ-13 to the Asthma Control Test (ACT) questionnaire (29), and the
Positive Health Behaviors Scale (PHBS) (30). The hypothesis behind using
the ACT and PHBS was that participants with higher AAMQ-13 scores were
expected more than the low-scoring ones to have well-controlled asthma.
In addition, participants with higher AAMQ-13 scores were more expected
to score higher in the PHBS, indicating that adherent patient generally
have a better lifestyle.