Justification
In World Brain (1938), H. G. Wells predicted that for an educated citizenship in a modern democracy, statistical thinking would be as indispensable as reading and writing. At the beginning of the 21st century, we have succeeded in teaching almost everyone reading and writing, but not statistical thinking – how to understand risks and uncertainties in our technological world. This forum addresses the problem of literacy in health care, from how research evidence is generated to how it is modified by the media and understood by doctors and patients who try to make sense of health statistics. Scientific and public policy studies on health have paid relatively little attention to people's health literacy, while technological, bureaucratic, and economic questions continue to dominate health policies. The few existing studies indicate that many patients, physicians, and political decision makers do not have the skills to evaluate the pros and cons of new technologies and do not even seem to notice or care. This state of affairs leads to unnecessary physical and emotional suffering of patients, promotes inefficiency in health care, and wastes money through overtreatment and overmedication. The goal of the proposed forum is a systematic analysis of the scope of the problem, its causes, and the possible contribution of cognitive, medical, and economic sciences to improve health literacy. We illustrate the problem with three case studies from the UK, Germany, and the US.
Scared Patients. Since the introduction of the contraceptive pill in the 1960s, British women have gone through several "pill scares." In the mid-90s, the press reported a warning by the UK Committee on the Safety of Medicines that third-generation oral contraceptive pills containing desogestrel or gestodene increased the risk of venous thromboembolism twofold, that is, by 100%. Many women reacted with panic and stopped taking the pill, which led to unwanted pregnancies (Jain et al., 1998) and resulted in an estimated 13,000 abortions above normal. The study cited in the news had actually shown that out of every 7,000 women who took the second-generation pill, 1 had a thromboembolism, and among women who took the third-generation pill, this number increased from 1 to 2. The difference between a relative risk increase (100%) and an absolute risk increase (1 in 7,000) was not known to these poor women. Both citizens and the pharmaceutical industry suffered, while the journalists profited from a front-page story.
Innumerate Physicians. In the US and Europe, women between 50 and 70 are encouraged to participate in screening for breast cancer. Mammography is not a highly reliable test, so it is important that physicians inform participants that out of every 10 women who test positive, only 1 actually has cancer. A positive mammogram is like an activated car alarm – usually a false alarm. Yet most physicians do not seem to know the relevant medical studies. According to studies with hundreds of gynecologists, radiologists, and other specialists, the majority believes that out of every 10 women who test positive, 8 or 9 have cancer (Gigerenzer et al., 2008; Hoffrage et al., 2000). Consider what unnecessary fear these physicians cause in patients with a positive test. Even when physicians were given the relevant numbers, such as a prevalence of breast cancer (1%), a sensitivity (90%), and a false positive rate (9%), most were confused by percentages. To this day, effective training in statistical thinking in medical schools is barely existent. Yet it is indispensable, given that the division of labor, time pressure and the absence of statistical records make learning from experience difficult in medicine.
Trust contra Evidence. Lack of statistical thinking is not the only cause of health illiteracy: Trust and paternalism are another. Berg et al. (2008) studied the decisions for or against PSA screening in a group that promotes rational thinking and cost-benefit analyses: neoclassical economists. Medical institutions such as the National Cancer Institute and the U.S. Preventive Services Task Force explicitly recommend that instead of automatically undergoing PSA screening, men should weigh costs and benefits individually in order to decide whether or not to take the test. The reason is that the test's benefits are not proven, but its harms are (such as incontinence and impotence following surgery after a positive test). Yet 95% of economists said that they had not consulted any medical source, and two thirds answered that they had not weighted pros and cons but simply followed the recommendation of their doctor (or wife). The emotional heuristic "trust your doctor" seems to dominate the decisions of even those trained to think statistically.
These three cases illustrate the phenomenon of health illiteracy and some of its causes. In health care, lack of understanding numbers (innumeracy) is generally presented as a problem of uneducated or poor patients. That educated patients also rarely ask questions about benefits and harms of treatment is less known, while the lack of risk literacy among physicians has gone mostly unnoticed and has yet to be understood in its full implications. The proposed forum will discuss the psychological, legal, and institutional aspects of health literacy. Along with trust, the illusion of certainty (for instance, every second German citizen believes that a screening test result is certain) inhibits statistical thinking. The German law states that patients have a right to information about their state of health, whether full or limited, written or oral, and assumes that physicians understand the risks, thereby neglecting the discrepancy between normativity (what the law assumes) and normality (many physicians' innumeracy). Health institutions often see their mission as fostering compliance rather than comprehension, publishing information brochures that omit medical results if they conflict with that goal. Under these circumstances, the ideals of informed consent and shared decision making cannot be achieved.
This Forum will focus on health literacy in preventive medicine; that is, in situations where patients have no symptoms or pain that might conflict with deliberate thinking. We will approach the questions from different theoretical perspectives, including health economics, game theoretical analysis, the psychology of decision making and risk, an institutional analysis of the conditions under which physicians work and feel liable to malpractice suits, and an analysis of the emotional relationship between physician and patient as well as the degree to which it interferes with patients' active search for information.
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