Objective: To study the psychometric properties of the Diabetes Fear of Injecting and Self-Testing Questionnaire (D-FISQ).
Research design and methods: Two groups of patients were studied. Sample A consisted of 252 insulin-treated diabetes patients. Sample B incorporated 24 insulin-treated patients with high scores (> or = 95th percentile) on the D-FISQ. Test-retest correlations were assessed in both samples. Discriminant and convergent validity of the D-FISQ were assessed with questionnaires concerning fear of hypoglycemia, trait anxiety, and fear of bodily injury, illness, or death. To evaluate criterion-related validity, sample B participated in a behavioral avoidance test (BAT), in which the current level of avoidance of either self-injecting or self-testing was determined. Exploratory factor analysis (EFA) was performed to study whether 2 factors (fear of self-injecting [FSI] and fear of self-testing [FST]) could be detected.
Results: Test-retest correlations ranged from 0.50 to 0.68 (P < 0.001). Correlations between D-FISQ and fear of hypoglycemia, trait anxiety, and fear of bodily injury, illness, or death ranged from 0.28 to 0.45 (P < 0.001). Patients who refused to do a BAT for self-injecting or self-testing had higher scores on FSI (P = 0.095) and FST (P = 0.01). EFA yielded 2 separate factors, FSI and FST.
Conclusions: Results from this study support reliability and validity of the D-FISQ, a self-report instrument that can be used for both clinical and research purposes.