A new treatment satisfaction measure for asthmatics: a validation study

The Patient Satisfaction with Asthma Medication (PSAM) questionnaire was developed because no treatment satisfaction questionnaire could be identified that was comprehensive yet brief enough for use in clinical trials. Adult moderate asthmatics residing in Canada using an inhaled medication (either salmeterol, formoterol, or albuterol) self-administered the questionnaire, which also included the Asthma Quality of Life Questionnaire (AQLQ). A total of 53 asthmatics (70% female, 45% married, mean age: 47 years) completed the questionnaire. Using variable clustering, four PSAM scales were identified: Inhaler Properties, Comparison with Other Medications, Overall Perception of Medication, and Relief. Internal-consistency reliability provided evidence of reliability and lack of redundancy (Cronbach's Alpha: 0.82-0.88). Test-retest reliability was acceptable (ICC values at or near 0.70). As expected, interscale PSAM correlations were moderate to high; correlations between the PSAM and the AQLQ were low to moderate. To assess known groups validity, respondents were categorized by self-reported degree of asthma control: 'very well controlled', 'somewhat controlled', and 'not well controlled'. Significant between-groups differences were found on all PSAM scales except Inhaler Properties. Patients categorized as 'very well controlled' tended to report highest PSAM scale scores. The PSAM questionnaire demonstrated reliability and validity in moderate asthmatics. Responsiveness should be assessed in future, prospective studies.