The objective of this article is to report the development of a tool to assess powerlessness in adult patients. Theoretical, empirical and analytical psychometric based procedures were applied to develop the tool. The tool was tested in 210 patients for item selection, reliability and validation estimate and it consisted of 12 items in three domains: "Capacity to perform behavior" (alpha=0.845); "Self-perception of decision making capacity" (alpha=0.834); and "Emotional responses to perceived control" (alpha =0.578). The total alpha was 0.799. Criteria validity was estimated by testing the association between the developed instrument and a general statement on control perception (p<0.000). The Powerlessness Assessment Tool will be useful to assess this nursing diagnosis as well as for the selection and evaluation of interventions.
Nursing diagnosis; Psychometrics; Perception; Validation studies
