[Spanish validation of the MacArthur Competence Assessment Tool for Treatment interview to assess patients competence to consent treatment]

Abstract

Background and objective: To validate the MacArthur Competence Assessment Tool for Treatment (MacCAT-T) Spanish version, which assesses the mental capacity of patients to consent treatment, by examining 4 areas (Understanding, Appreciation, Reasoning and Expressing a choice).

Sample: 160 subjects (80 Internal Medicine inpatients, 40 Psychiatric inpatients and 40 healthy controls).

Instruments: MacCAT-T, Mini-Mental Status Examination (MMSE).

Procedure: Feasibility study, reliability and validity calculations (against to gold standard of clinical expert).

Results: Mean duration of the MacCAT-T interview was 18min. Inter-rater reliability: Intraclass correlation coefficient for Understanding=0.98, Appreciation=0.97, Reasoning=0.98, Expressing a choice=0.91. Internal consistency (Cronbach's alpha): Understanding=0.87, for Appreciation=0.76, for Reasoning=0.86. Patients considered to be incapable (gold standard) scored lower in all the MacCAT-T areas. Poor performance on the MacCAT-T was related to cognitive impairment assessed by MMSE.

Conclusions: Spanish version of the MacCAT-T is feasible, reliable, and valid for assessing the capacity of patients to consent treatment.

Keywords: Bioethics; Bioética; Capacidad de decisión; Consentimiento informado; Decisional capacity; Estudio de validación; Informed consent; MacArthur Competence Assessment Tool for Treatment; Validation study.