Development of an instrument to evaluate the capacity of elderly persons to make personal care and financial decisions

Evaluations of the competency of elderly individuals for guardianship proceedings have been criticized frequently in legal and mental health literature. This study describes the development and evaluation of a measure of the abilities of elderly individuals to make decisions in situations commonly confronting elderly persons for whom guardianship is sought. Before the study began, a legal analysis was conducted of statutory standards in all fifty states and the District of Columbia for determining competency in guardianship proceedings. This analysis provided the foundation for the study, which took place in two stages: (1) initial development of the instrument ensuring content validity; and (2) evaluation of reliability and validity. The test was developed in stage one through a situational analysis combining theory with interviews and surveys of legal and mental health professionals. The resulting instrument--the Decisionmaking Instrument for Guardianship (DIG)--consists of eight vignettes followed by a structured interview. The vignettes are problem situations commonly confronted by elderly individuals for whom guardianship is considered. The structured interview was based on contemporary problem-solving theories and earlier instruments. A detailed scoring system, including a manual, was developed. In stage two, a sample of 61 subjects from ages 61 to 90 were administered the DIG, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery of neuropsychological tests, the Block Design and Vocabulary subtests of the WAIS-R, and a modified version of the Thinking Rationally About Treatment (TRAT-2) instrument (a measure of competence to provide informed consent). Complete data were obtained for 56 subjects. Internal consistency for the DIG as measured by coefficient alpha was.9158. When the scores of two research assistants on ten DIG protocols were compared with the researcher's scores, the interscorer reliability coefficients were.9704 and.9613 The correlations between the DIG and the TRAT-2 Block Design subtest (.6406), CERAD (.5940), and Vocabulary subtest (.5425) were all significant {dollar}(p<.001){dollar} and provided support for the construct validity of the DIG. The DIG is a promising tool for further research and may prove useful to clinicians, although it cannot be viewed as a definitive measure of competency in guardianship proceedings.