Materials and Methods: In the first section of this cross-sectional study, the stages of change in self-management of patients with T2DM questionnaire were developed by the researcher. The questionnaire included eight questions in the field of using medication, a healthy diet, and physical activity. In the second section, the content validity and face validity of the questionnaire were assessed by the opinions of 11 expert panelists in the field of health education and nutritional sciences. Finally, construct validity was carried out by exploratory factor analysis (EFA) among 206 patients with T2DM in an outpatient clinic in Ardabil in the northwest of Iran.

Results: The total content validity index (CVI), content validity ratio (CVR), and face validity were 0.60-0.91, 0.81-1, and 4.32-4.82, respectively. The number of questions increased up to 10. In addition, EFA results showed that Kaiser-Mayer-Olkin and the total variance extracted were 0.69 and 23.6, respectively, and Bartlett tests were statistically significant (P=0.000). Finally, reliability analysis indicated a moderate level of internal consistency (ICC = 0.89) and Cronbach"s alpha of 0.63.

Conclusions: This questionnaire with 10 items and one factor was found to be valid and reliable as a simple and effective tool for self-care on the stages of change in patients with T2DM.