GETTING MEANINGFUL INFORMED CONSENT FROM OLDER ADULTS - A STRUCTURED LITERATURE-REVIEW OF EMPIRICAL-RESEARCH

OBJECTIVES: To perform a structured literature review of the published empirical research on informed consent with older adults in order to make recommendations to improve the informed consent process and to hi ghlight areas needing further examination. DESIGN: Relevant literature was identified by searching electronic databases (AGELINE, BIOETHICSL INE, Cancer-Lit, Ethics Index, Health, LegalTrac, MEDLINE, PAIS Intern ational, PsycInfo, and Sociofile). Studies were included if they were reports of primary research data about informed consent and, if patien ts or other subjects were used, older subjects were included in the sa mple. Data related to the aspect of informed consent under study (recr uitment, decision-making capacity, voluntariness, disclosure of inform ation, understanding of information, consent forms, authorization, and policies and procedures) were abstracted and entered into a specially designed database. MEASUREMENTS: Characterization of the population, age of subjects, setting, whether informed consent was being studied i n the context of research or treatment, study design, the nature of ou tcome or dependent variables, independent variables (e.g., experimenta l conditions in a randomized controlled trial or patient/subject chara cteristics in a nonrandomized comparison), and results according to th e aspect of informed consent under study. RESULTS: A total of 99 artic les met all the inclusion criteria and posed 289 unique research quest ions covering a wide range of aspects of informed consent: recruitment (60); decision making capacity (21); voluntariness (6);disclosure (30 ); understanding (139); consent forms (7); authorization (11); policie s (13); and other (2). In the secondary analyses of numerous studies, diminished understanding of informed consent information was associate d with older age and fewer years of education. Older age was also some times associated with decreased participation in research. Studies of disclosure of informed consent information suggest strategies to impro ve understanding and include a variety of novel formats (e.g., simplif ied, storybook, video) and procedures (e.g., use of health educators, quizzing subjects, multiple disclosure sessions). CONCLUSIONS: A syste matic review of the published literature on informed consent reveals e vidence for impaired understanding of informed consent information in older subjects and those with less formal education. Effective strateg ies to improve the understanding of informed consent information shoul d be considered when designing materials, forms, policies, and procedu res for obtaining informed consent. Other than empirical research that has investigated disclosure and understanding of informed consent inf ormation, little systematic research has examined other aspects of the informed consent process. This deficit should be rectified to ensure that the rights and interests of patients and of human subjects who pa rticipate in research are adequately protected.