by ecancer reporter Clare Sansom

In developed countries, people are increasingly expected to make complex decisions about their medical treatment: for example, whether to change medication for a chronic condition, undertake elective surgery such as hip or knee replacement, or take up an opportunity for screening. In oncology the most significant of these decisions generally relate to screens for colon, breast, prostate or cervical cancer. If patients are to make rational decisions they need both to have the necessary knowledge and to feel confident that they do. Many studies have suggested that people tend to over-estimate their knowledge and judgement about complex issues, including medical ones.

Karen Sepuchra from Harvard Medical School and her co-workers have sought, in the DECISIONS study, to explore the relationship between patients’ feeling informed about their own conditions and the treatments offered, and their levels of factual knowledge. This study involved questioning 2575 Americans over the age of 40 who had taken a decision in the preceding two years regarding at least one of nine medical interventions: prescription medication for hypertension, hypercholesterolemia, or depression; screening for breast, prostate or colon cancer; and elective surgery for joint replacement, cataract, or lower back pain. Respondents were asked for basic demographic information, about access to medical care, and about their level of trust in their primary care provider. They were also asked how far they felt well-informed about the decisions they made, and they were asked open-ended and multiple choice questions to gauge their actual level of knowledge of the treatment offered. One example of an open-ended question on cancer screening was “Of every 100 men, about how many die of prostate cancer?” The relationship between demographics, perceived knowledge and actual knowledge was analysed using multivariate regression.

Overall, the researchers found that about 36% of patients felt extremely well-informed about the decisions that they had to make, with equal numbers of the rest feeling well-informed and somewhat or not at all well-informed. More felt extremely well-informed about surgery than about the other types of decision. There was, however, no significant correlation between whether patients felt well-informed and their level of factual knowledge. Most patients revealed significant gaps in their knowledge of the risks and benefits of the proposed treatments. Furthermore, patients with low income (< $50,000 p.a.); with African-American ethnicity; with high school education or less; and who had “complete” trust in their primary care provider were significantly more likely to rate themselves as extremely well-informed.

Previous studies have suggested that it is people who know more who understand the gaps in their own knowledge and who therefore perceive that they know less. This study implies that it is those patients with the least resources in terms of income and education who are most likely to feel that they have enough information to make decisions about their healthcare. Physicians, including oncologists, will need to provide patients with specific knowledge and check that they understand the benefits and risks of treatments – including population-based screening of individuals without known health problems – rather than relying on patients’ own reported levels of understanding.

Reference

Sepucha, K.R., Fagerlin, A., Couper, M.P., Levin, C.A., Singer, E. and Zikmund-Fisher, B.J. (2010). How Does Feeling Informed Relate to Being Informed? The DECISIONS Survey. Medical Decision Making 30: 77S. doi: 10.1177/0272989X10379647