Valoración de la capacidad para consentir participar en investigación en pacientes con patología psiquiátrica y adictivapropuesta de una intervención

Zusammenfassung

ABSTRACT Informed consent is a key element of ethical clinical research. Addicted and psychiatric population may be at risk for impaired consent capacity. Problems with procedures may also contribute to patient's 'difficulties in understanding consent forms. The aims of this doctoral thesis are to evaluate the association between capacity to consent research and different psychiatric and substance use disorders; to characterize predictors of impairments in research decision-making capacity and, finally, to explore if a brief technologically based information presentation of the informed consent process may improve participant's understanding and satisfaction. For these purposes 242 subjects: 192 outpatients with different mental disorders following the DSM criteria, were interviewed (50 with a psychotic disorder, 46 with a mood disorder, 43 with an anxiety disorder, 53 people with an alcohol, cocaine, cannabis or mixed substance disorders and 50 non psychiatric comparison subjects) and a binary judgment of capacity/incapacity was made guided by the Spanish version of the MacArthur Competence Assessment Tool for Consent Research. This interview appears to be the single most widely used validated instrument and receives the most empirical international support for formal assessment of the four commonly recognized dimensions of decisional capacity. Demographics and clinical information were assessed by cases notes and several scales. We reassessed with a computer-based presentation designed by us all the psychiatric patients who were initially found to lack capacity (n=41) and a comparison group of 47 patients randomly drawn from the people who were initially regarded as being capable. We also readministered clinical and cognitive scales and asked about willingness to participate and which presentation of the consent form did they prefer. Among the results obtained, we highlight that 70% people with psychiatric or addictive disorders lacked research-related decisional capacity. More than 60% of psychiatric population improved their decisional capacity when we reassessed them with the interactive program. Patients with anxiety disorders performed the best on the capacity evaluations and patients with psychotic disorders had the worst performance, although when the other variables associated with incapacity on the multivariate analysis are considered, psychiatric diagnoses had no longer impact on the probability of being capable. There were no statistically significant differences between neither clinical and control groups nor substance use disorders subgroups in terms of capacity to consent to research. Low understanding and appreciation MacArthur Competence Assessment Tool for Consent Research subscales scores and cognitive impairment were the factors most closely associated with lack of capacity. Patient satisfaction and their hypothetical willingness to participate in the study improved with the computer-assisted consent. On the basis of these results, we can conclude that it is unwise to draw absolute conclusions about capacity to make research decisions on the basis of a SUD/ psychiatric diagnosis, because most of them remain capable of giving meaningful consent under most circumstances. If research-related decision-making capacity is impaired, can be improved with educational interventions designed to remedy common legalistic printed consent limitations. Rather than restrict research participation for categories of patients, emphasis should be placed on assuring that information is provided in a comprehensible form suited to the potential participant's power of understanding. The assumption that a person suffering from mental illness or a SUD will have always impaired decision making abilities is therefore, unfounded and stigmatising. We found some factors associated with lack of capacity that shed light about which individual subjects may require more intensive screening or education especially for greater-than-minimal-risk studies like our study was