Psychometric analysis of the Spanish and Catalan versions of the Diabetes Self-Care Inventory-Revised version questionnaire

Abstract

Background: The purpose of this study was to validate the Spanish and Catalan versions of the Diabetes Self-Care Inventory-Revised Version (SCI-R) questionnaire to assess the degree of adherence to self-care among adults with diabetes.

Methods: We validated the Spanish and Catalan translation from, and back translation to, English and cultural adaptation of the SCI-R in type 1 diabetes patients on multiple insulin doses or continuous subcutaneous insulin infusion and in type 2 diabetes patients on oral agents and/or insulin. Internal reliability, structural validity, and external validity (correlation with glycated hemoglobin) were evaluated. Responsiveness to change was assessed in patients 1 year after onset of type 1 diabetes and following a structured education program.

Results: The SCI-R presented good internal reliability Cronbach's α: 0.75, test-retest reliability (r = 0.82) and structural validity (r > 0.40). The external validity was also good; the SCI-R correlated with HbA1c in patients with type 1 diabetes on multiple insulin doses (r = -0.50) or continuous subcutaneous insulin infusion (r = -0.66) and in patients with type 2 diabetes on multiple insulin doses (r = -0.62). However, it was not satisfactory in patients on oral agents (r = -0.20) and/or bedtime insulin (r= -0.35). Responsiveness to change was analyzed in 54 patients (age 27.3±7.4 years, 26% men, HbA1c 6.8% ±1.1%); the SCI-R score was 72.3% ±13.7% and correlated negatively with glycated hemoglobin (r= -0.42) and 3 scales of the Diabetes Quality of Life questionnaire (lower score indicating better perception): Impact (r = -0.37), Social Worry (r= -0.36) and Diabetes Worry (r = -0.38), all at P < 0.05.

Conclusion: The Spanish and Catalan versions of the SCI-R questionnaire show good psychometric properties and both could be considered as useful tools for evaluating self-care behavior in patients with type 1 or type 2 diabetes. However, there are still some subgroups of patients with type 2 diabetes in which the validity of this questionnaire needs further evaluation.