Clinical issues in the assessment of competency.

The evaluation of a patient's competency to consent to treatment, regardless of the test of competency used, can be substantially affected by a number of clinical factors. The authors point out that, in assessing competency, the clinician must consider 1) psychodynamic elements of the patient's personality, 2) the accuracy of the historical information conveyed by the patient, 3) the accuracy and completeness of the information disclosed to the patient, 4) the stability of the patient's mental status over time, and 5) the effect of the setting in which consent is obtained. Inattention to these factors can lead to errors in assessment of competency that can have important implications for patient care.