Background: The decision to participate in a research intervention or to undergo medical treatment should be both informed and voluntary.
Objective: The aim of the present study was to develop an instrument to measure the perceived voluntariness of parents making decisions for their seriously ill children.
Methods: A total of 219 parents completed questionnaires within 10 days of making such a decision at a large, urban tertiary care hospital for children. Parents were presented with an experimental form of the Decision Making Control Instrument (DMCI), a measure of the perception of voluntariness. Data obtained from the 28-item form were analyzed using a combination of both exploratory and confirmatory factor analytic techniques.
Results: The 28 items were reduced to 9 items representing 3 oblique dimensions: Self-Control, Absence of Control, and Others' Control. The hypothesis that the 3-factor covariance structure of our model was consistent with that of the data was supported. Internal consistency for the scale as a whole was high (0.83); internal consistency for the subscales ranged from 0.68 to 0.87. DMCI scores were associated with measures of affect, trust, and decision self-efficacy, supporting the construct validity of the new instrument.
Conclusion: The DMCI is an important new tool that can be used to inform our understanding of the voluntariness of treatment and research decisions in medical settings.