Associations between diabetes duration and self-stigma development in Japanese people with type 2 diabetes: a secondary analysis of cross-sectional data

Objectives To examine the associations between self-stigma and diabetes duration in a sample of Japanese people with type 2 diabetes. Design A secondary analysis of a cross-sectional study. Setting Two university hospitals, one general hospital and one clinic in Tokyo, Japan. Participants Outpatients with type 2 diabetes aged 20-74 years and receiving treatment from diabetes specialist physicians (n=209) completed a self-administered questionnaire. Primary and secondary outcome measures Self-stigma was measured as the primary outcome. Patient Activation Measure, body mass index and haemoglobin A1c were measured as secondary outcomes. Results One-way analysis of covariance showed significant differences in self-stigma levels between the five groups of diabetes duration (<= 5 years, 6-10 years, 11-15 years, 16-21 years and 22 years or more) after controlling for age, gender, education, marital status, diabetes treatment (insulin use) and diabetes-related complications, F(4,198)=2.83, p=0.026. Multiple comparisons using Bonferroni correction showed statistically significant differences in self-stigma levels between the groups with <= 5 years (95% CI 59.63 to 69.73) and 11-15 years with diabetes (95% CI 71.12 to 80.82; p=0.020). The highest mean level of self-stigma was observed in the group having diabetes for 11-15 years. Conclusions Self-stigma was associated with diabetes duration and was lowest after diagnosis and gradually increased, with its highest levels being observed in those having diabetes for 11-15 years. Self-stigma takes time to develop and gradually increases in individuals as it is learnt through direct experiences of diabetes-related stigma after self-administering treatment in everyday social situations.