A new brief instrument for assessing decisional capacity for clinical research

There is a critical need for practical measures for screening and documenting decisional capacity in people participating in different types of clinical research. However, there are few reliable and validated brief tools that could be used routinely to evaluate individuals' capacity to consent to a research protocol.

To describe the development, testing, and proposed use of a new practical instrument to assess decision-making capacity: the University of California, San Diego Brief Assessment of Capacity to Consent (UBACC). The UBACC is intended to help investigators identify research participants who warrant more thorough decisional capacity assessment and/or remediation efforts prior to enrollment.

We developed the UBACC as a 10-item scale that included questions focusing on understanding and appreciation of the information concerning a research protocol. It was developed and tested among middle-aged and older outpatients with schizophrenia and healthy comparison subjects participating in research on informed consent. In an investigation of reliability and validity, we studied 127 outpatients with schizophrenia or schizoaffective disorder and 30 healthy comparison subjects who received information about a simulated clinical drug trial. Internal consistency, interrater reliability, and concurrent (criterion) validity (including correlations with an established instrument as well as sensitivity and specificity relative to 2 potential "gold standard" criteria) were measured.

Reliability and validity of the UBACC.

The UBACC was found to have good internal consistency, interrater reliability, concurrent validity, high sensitivity, and acceptable specificity. It typically took less than 5 minutes to administer, was easy to use and reliably score, and could be used to identify subjects with questionable capacity to consent to the specific research project.

The UBACC is a potentially useful instrument for screening large numbers of subjects to identify those needing more comprehensive decisional capacity assessment and/or remediation efforts.