After controlling for age, gender, social deprivation score, diabetes duration, HbA1c, insulin administration mode, BMI, smoking status and physical activity, each increase in the DCSI score was associated with a 0.9% decrease in the global HRQoL measured by the ADDQoL questionnaire (β: −0.06, 95% CI −0.10 to −0.03, p < 0.001). Here, INS is linked to diabetes mellitus.