Promoting Disability Justice through better Capacity Assessment: A Tool to Evaluate Capacity to Designate a Surrogate in Patients who Otherwise Lack Decisional Capacity

Abstract: Often, when patients are judged to lack DMC for treatment decisions, they are also assumed to lack the capacity to designate a surrogate (CDS). In a previous publication, we provide normative analysis of the unique aspects of CDS. Here we report pilot data on a novel instrument for assessing CDS. We conducted 52 interviews with participants diagnosed with dementia using a mixed-methods approach to evaluate subject’s ability to (1) consistently name a surrogate, (2) understand aspects of surrogacy, and (3) provide a rationale for a choice. Analysis showed high interrater reliability with Kappa across all items ranging from a low of .709 (p <.001) to 1.00 (p <.001) (where -1.0 is perfect disagreement and 1.0 is perfect agreement). There were no statistically significant differences between patients with and without DMC in terms of making a choice. In terms of understanding the conditions for needing a surrogate, the process of designating a surrogate, and the functional role of a surrogate, those lacking DMC scored lower than those with DMC (F-statistic range 5.35 to 24.16; p<.05 to p<.001). But on each of these dimensions, the CDS instrument identified participants who otherwise lacked DMC, but nonetheless had full understanding of the need, process, and role of a surrogate. Ultimately, the CDS tool shows that there are patients who lack DMC but who can validly designate a surrogate. Combined with strong reliability and evidence of validity, the CDS tool may be a highly useful instrument to protect and promote healthcare participation of this vulnerable population.

Jason Wasserman – Oakland University William Beaumont School of Medicine