Drug Attitude Inventory in Patients with Bipolar Disorder: Psychometric Properties

A negative attitude toward treatment is a major obstacle to treat bipolar disorder. The current study aimed at assessing the reliability and validity of Persian version of drug attitude inventory (DAI-10) in patients with bipolar I disorder and finding its relationship with patients’ compliance in order to predict the disorder. To assess test-retest reliability, 30 outpatients with bipolar I disorder were selected. They were asked to answer the questions at the onset of the study and four to ten days later. Then, the relationship between DAI-10 scores of 82 patients in bipolar disorder patients’ follow-up (BDPF) study, and medication possession ratio (MPR) were investigated. The patients were divided into poor and good compliance, and cut off point of the tool was assigned. Positive and negative predictive value of DAI score was also calculated. Test-retest reliability was 0.805 and Cronbach’s α 0.787. Concurrent validity between DAI-10 score and that of the MPR at the study time was 0.676, and positive predictive value of DAI-10 score for medication compliance at assessment time was about 88.9%. Predictive validity of DAI-10 score for next six months was about 0.663 and cut off point +1, with the specificity of 81.5% and sensitivity of 89.1%; the positive predictive value of questionnaire score for medication compliance was 90.7%. The Spearman correlation coefficient between the two tests was 0.822 (95% confidence interval (CI): 0.652 - 0.901). DAI-10 is a reliable and valid tool to identify attitude of patients with bipolar disorder type I towards treatment with medications.