The interpretation of the two components was different (however, very close) from the previously domains of interest (Belief, Barrier, and Behavior) identified by the research team. In designing the AAMQ-13, all potential items were stemmed from these three domains. The factor analysis suggested the presence of two factors, intrestingly, all of the ‘Barrier’ domain items loaded strongly on component one, and all of the ‘Behavior’ domain items loaded strongly on component two, while the ‘Belief’ domain items (n= 3) were found to be distributed between the two components (Table V). A person’s behavior is determined by his/her intention to perform a behavior as stated in the Theory of Reasoned Action. The person’s intention to perform a behavior is influenced by the person’s attitude toward that behavior and the environmental surroundings (40). This would highly explain why the last domain (Beliefs) did not show as a separate component in factor analysis. As beliefs cause barrier and lead to behavior; as a consequence, the AAMQ-13 picks the endpoints. Therefore, we decided to extrapolate the factor analysis results and conclude that the AAMQ-13 is not only able to identify non-adherence patients and classify their adherence level (poor, moderate, good, and excellent adherence), but it can also give adequate information about the patterns of non-adherence (intentional or unintentional non-adherence). This can be achieved by comparing the total score of the five Behavior items (items number 3, 4, 5, 6, and 7) which represent intentional non-adherence and the total score of the five Barrier items (items number 8, 9, 10, 11, and 12) which represent unintentional non-adherence.
The AAMQ-13 has a high sensitivity (0.85) and specificity (0.95) which makes it a good candidate to assess asthmatic patient adherence to medications. The sensitivity of the most commonly used published questionnaires approximately ranged from 0.63 in the PIAQ to 0.848 in the TAI (when the cut off of TAI score was 45) (15,41). As for specificity ranged from 0.226 in the TAI, to 1.0 in the BMQ (for the regimen screen part in the questionnaire) and 0.91 in the PIAQ (13,15,41).
Methods used to assess the criterion validity of each questionnaire varied widely from one questionnaire to another; some questionnaires used subjective method (e.g. therapist report) such as the DAI, while other questionnaires chose an objective method (e.g. the medication event monitoring system (MEMS)) such as the BMQ and the BARS (11,13,16). The AAMQ-13 was validated using both methods.
This study comes with few limitations; due to the coronavirus pandemic and public quarantine that happened in March 2020 in the country, interviewing patients was impossible in phase four (n= 213) and we were not able to meet them face-to-face. Thus, in order to complete the study, we decided to conduct the last phase of the study on an online platform. Yet, the online procedure followed gave the needed results to answer the main aims of the study. Furthermore, the AAMQ-13 has been studied in the Arabic population and would need validation in an English-speaking population.