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Measuring Voluntariness of Consent to Research

The conceptual complexity of the term voluntariness has resulted in relatively few empirical studies of the voluntariness component of consent to research. As the call for a formal assessment of voluntariness to be incorporated into the consent process intensifies, more researchers are responding to the challenge of developing a valid and reliable measure of voluntariness. The purpose of this article was to summarize and describe the empirical literature on voluntariness of consent. As part of a broader study on the voluntariness of consent to research, existing empirical studies of voluntariness of consent to research were reviewed to establish how voluntariness of consent to research has been assessed to date. Fifteen studies using different voluntariness assessment instruments were identified and included in the review. The review found that little attempt has been made to systematically collect data on the reliability and validity of voluntariness assessment instruments. No two instruments reviewed were found to be based on a shared conceptualization of voluntary consent to research.