Development and Psychometric Assessment of Instrument “ Self-efficacy for Patients with Beta Thalassemia Major”

Abstract

Abstract Introduction: At present, chronic diseases such as thalassemia is one of the important challenges of the health care system. Self-care is the most important factor which could influence patients' quality of life and it could reduce anxiety, depression, and fatigue of patients with thalassemia. Self-efficacy is an important prerequisite for successful self-care and behavior change. Also, it is the most important determinant of self-care behaviors. Given the importance of the self-efficacy construct, the challenge in studying self-efficacy in patients with thalassemia major is the lack of specific tools for measuring it. Therefore, this study was conducted with the aim of designing and psychometric evaluation the self-efficacy tool for patients with thalassemia major. Method: It was a mixed method study with a sequential exploratory design. In the first stage, a qualitative study with conventional content analysis was conducted to explain the self-efficacy and its dimensions in patients with thalassemia major. Data were collected using unstructured interviews. The research sample included 16 patients with thalassemia major who were selected using a purposeful sampling method. In the next stage, items of the tool were developed using the findings of the qualitative stage and reviewing literature. Then, the face validity of the tool was checked and its content validity was examined through determining the content validity ratio and index. Also, the tool's construct validity was checked using the exploratory factor analysis with the participation of 199 patients with thalassemia major, and its convergent validity was considered using the Rosenberg self-esteem tool with the participation of 102 patients. The tool's reliability was assessed by the internal consistency reliability, and the stability was checked by the test-retest method with the cooperation of 23 patients with thalassemia major in an interval of 2 weeks. Results: Analysis of the qualitative data led to the identification of four categories; including ability belief of "self-acceptance", "change", "activites, management", and "disease acceptance". After explaining the concept of self-efficacy of patients with thalassemia major, the tool draft was prepared with 54 items on a six-point Likert scale. After determining its face validity and content validity, a tool with 37 items was prepared for the next step which was determining the tool's construct validity. In exploratory factor analysis, 2 items with a common variance of less than 0.2 with other items; were removed from the tool. Finally, a tool with 35 items and three factors including "self-acceptance," "adaptation belief," and "treatment adherence/disease control belief" was designed. The cumulative variance of the three factors was 49.89%. The convergent construct validity was also determined by comparing the designed tool with Rosenberg self-esteem tool and calculating the Pearson correlation coefficient (r = 0.38). The internal consistency reliability of the whole scale was confirmed with Cronbach's alpha coefficient (α) of 0.93 and the intra-class correlation coefficient (ICC) of 0.94. Conclusion: The results showed that patients with thalassemia major who are self-efficient have belief in accepting their limitations and abilities. The self-efficient patient who has self-acceptance; believes in using the strategies of coping, adapts with the society's view towards the disease and himself/herself, as well as the changes resulting from the disease in his/her appearance. In addition, the self-efficient patient with thalassemia major believes in the ability to adhere the treatment to prevent and control the complications of the disease, so that he/she could actively participate in his/her physical and mental health and could improve his/her quality of life. The "Self-Efficacy Scale for Patients with Thalassemia Major" has appropriate psychometric properties to measure the self-efficacy of these patients.