Development and validation of the self-regulation of blood donation scale for blood donors.

Background: Because knowledge of blood donor motivation is crucial in guiding recruitment and retention efforts, the present study aimed at developing and validating a new scale as a multidimensional measure of blood donation motivation from the perspective of the self- determination theory.

Methods: This study was conducted in three phases from September 2022 to May 2023. The first phase involved developing a draft scale based on a literature review. In the second phase, face and content validity were performed. The third phase used a cross-sectional design to assess the construct validity and internal consistency of the initial scale following administration to blood donors with a history of at least one previous whole blood donation who visited the largest blood transfusion center in Iran. Of the 420 subjects who were recruited using a mixed sampling method, 343 who fully completed the initial version of the scale were subjected to an construct validity assessment using exploratory factor analysis with Equamax rotation and internal consistency using McDonald's omega coefficient.

Main results: The initial version of the scale consisted of 30 survey items with both a content validity ratio and a content validity index of 0.99. Exploratory factor analysis identified 24 items; grouped in six regulation factors (non-regulation, external regulation, introjected regulation, identified regulation, integrated regulation, and intrinsic regulation). The factors demonstrated adequate internal consistency with ω values ranging from 0.60 to 0.79.

Conclusion: The present study provides psychometric support for the newly developed questionnaire to evaluate donation motivation among blood donors in Iran or in other countries with similar language, and religious and cultural values.