Validity and reliability of the Chinese version of the Insulin Treatment Appraisal Scale among primary care patients in Hong Kong.

Abstract

Patients with diabetes mellitus often delay insulin initiation and titration due to psychological factors. This phenomenon is known as 'psychological insulin resistance'. Tools that identify psychological insulin resistance are valuable for detecting its causes and can lead to appropriate counselling. The Insulin Treatment Appraisal Scale was initially developed for western populations and has been translated and validated to measure psychological insulin resistance in Taiwan (Chinese version of the Insulin Treatment Appraisal Scale, C-ITAS). The current study examined the prevalence of psychological insulin resistance and the validity of the C-ITAS in a local population. This cross-sectional study involved 360 patients with diabetes mellitus from a government-funded general out-patient clinic who completed the C-ITAS questionnaire. The total C-ITAS score was compared for patients with psychological insulin resistance and those without, and the internal consistency and test-retest reliability of the C-ITAS were calculated. An exploratory factor analysis was used to identify factors within the C-ITAS. The prevalence of psychological insulin resistance was 44.9%. The internal consistency of the scale was high (Cronbach's alpha=0.78). The test-retest reliability was positive with all C-ITAS questions (0.294-0.725). The mean C-ITAS score was significantly higher among patients with psychological insulin resistance than those without (42.42 vs 35.78; P<0.001). The exploratory factor analysis, however, failed to identify the two clear factors identified in the original validation study. The C-ITAS appears to be a feasible and potentially useful tool for identifying psychological insulin resistance, but additional validation or translation is required before it can be widely used clinically.