Article Figures & Data
Figures
- Figure 1.
A ROC graph, based on data in Poythress et al.,36 that treats the MacCAT-CA Reasoning scale as a diagnostic test for incompetence to stand trial. Numbered markers represent (FPR, TPR) pairs associated with scores on the Reasoning scale. A smooth, binormal ROC is fitted to the data.
- Figure 2.
ROC curves for all three MacCAT-CA scales, based on data in Poythress et al.36 The dotted line (at FPR = 0.05) suggests that when detecting incompetence with high specificity, the Appreciation scale has the highest sensitivity. The circular markers represent points that maximize diagnostic information when the base rate of incompetence is 0.16 (the bottom left circle on each curve) and 0.30 (top right circle on each curve).
- Figure 3.
Hypothetical study results from a five-category rating of 200 defendants, half of whom are actually competent to stand trial. Gaussian distributions fit the rating data to the binormal assumption.
- Figure 4.
ROC graph based on hypothetical data in Figure 3. Segments of ROC curve areas labeled to indicate their sources in one of five rating categories. Four potential decision thresholds appear along the curve as circles that are fitted to a smooth curve according to the binormal assumption. The square labeled apparent accuracy based on yes-or-no opinions assumes that half the defendants rated 2, 3, and 4 are deemed competent and that these opinions are used to quantify accuracy.
Tables
- Table 1
Instructions to Experts Who Perform Court-Ordered Evaluations of Competence to Stand Trial (Utah Code 77-15-5(4))25
The experts shall consider … and address, in addition to any other factors determined to be relevant … : (a) the defendant's present capacity to: (i) comprehend and appreciate the charges or allegations against him; (ii) disclose to counsel pertinent facts, events, and states of mind; (iii) comprehend and appreciate the range and nature of possible penalties, if applicable, that may be imposed in the proceedings against him; (iv) engage in reasoned choice of legal strategies and options; (v) understand the adversary nature of the proceedings against him; (vi) manifest appropriate courtroom behavior; and (vii) testify relevantly, if applicable; (b) the impact of the mental disorder, or mental retardation, if any, on the nature and quality of the defendant's relationship with counsel; (c) if psychoactive medication is currently being administered: (i) whether the medication is necessary to maintain the defendant's competency; and (ii) the effect of the medication, if any, on the defendant's demeanor and affect and ability to participate in the proceedings. - Table 2
(FPR, TPR) Pairs that Maximize Each MacCAT-CA Scale's Information, Based on Data in Poythress et al.36
MacCAT-CA Scale BR FPR TPR Information Scale Score Interpretation (Impairment Level) Bits %max Understanding 0.16 0.181 0.517 0.053 8.3 9 Mild 0.30 0.204 0.548 0.081 9.2 10 Minimal Reasoning 0.16 0.118 0.479 0.071 11.2 9 Mild 0.30 0.140 0.514 0.106 12.0 9 Mild Appreciation 0.16 0.040 0.407 0.105 16.5 7 Clinically significant 0.30 0.054 0.441 0.148 16.8 8 Clinically significant Also shown are the amounts of information yielded by each scale (both in bits and as a percentage of the information that would be obtained from a perfect test), corresponding scale scores, and the MacCAT-CA interpretations of these scores. BR = assumed base rate.
