Informed consent: how much and what do patients understand?

OBJECTIVE: We sought to evaluate the degree of patients' understanding of several aspects of the informed consent process for surgery and clinical research. METHODS: We conducted a systematic search of PubMed (1961-2006) to identify relevant articles. RESULTS: We retrieved 23 and 30 eligible for inclusion articles regarding informed consent for surgery and clinical research, respectively. Regarding surgery, adequate overall understanding of the information provided and of the risks associated with surgery was shown in 6 of 21 (29%) and 5 of 14 (36%) studies providing relevant data, respectively. Regarding clinical research, adequate understanding of the aim of the study, the process of randomization, voluntarism, withdrawal, and the risks and the benefits of treatment was shown in 14 of 26 (54%), 4 of 8 (50%), 7 of 15 (47%), 7 of 16 (44%), 8 of 16 (50%), and 4 of 7 (57%) of studies providing relevant data, respectively. Satisfaction by the amount of the given information was shown in 7 of 12 (58%) studies involving surgery and 12 of 15 (80%) studies involving clinical research. CONCLUSIONS: Further attention should be drawn on enhancing patients' understanding regarding several components of the informed consent process for surgery and clinical research.