OBJECTIVES: Two patient self-report questionnaires were developed for use by physicians. They were intended to assess why diabetic patients were reluctant to switch their treatment from oral hypoglycaemic agents to insulin or to step up their insulin dosage when already treated with insulin. This study presents scores and psychometric validation for both questionnaires. METHODS: Patients treated with oral hypoglycaemic agents (n=1582) and patients already treated with insulin (n=1296) completed the questionnaire at baseline, Month 3 and Month 6. Psychometric properties were assessed: 1) structural analysis by Principal Component Analysis (PCA) with varimax rotation; 2) internal consistency reliability determination (Cronbach's alpha); and 3) concurrent validation (Spearman correlation coefficients with the Fear of Self-Injecting (FSI) score of the Diabetes Fear of Injecting and Self-testing Questionnaire (D-FISQ). The ability of scores to predict the switch to an insulin treatment and increased numbers of injections at the end of baseline visit was established by calculating the Area Under the ROC Curve (AUC). RESULTS: PCA analysis confirmed the final questionnaire structure of 14 items grouped into 3 dimensions (Acceptance/Motivation (AM), Insulin treatment: fear and constraints (FC), and Reluctance to be injected (RI)). Internal consistency reliability (Cronbach's alpha ranging from 0.74 to 0.82) and concurrent validity (FIS correlations of 0.41 for FC and 0.42 for RI) were good to excellent. The three scores were predictive of the unwillingness to be treated with insulin and to step up insulin treatment (AUC ranging from 0.65 to 0.87). The AM score was predictive of the switch to an insulin treatment and increased numbers of injections at the end of baseline visit (AUC of 0.80 and 0.66). CONCLUSION: The questionnaires are reliable, valid and a help for physicians in assessing the hurdles faced by diabetic patients starting or stepping up insulin treatments.