Doctors who see a bowel cancer patient tend to refer more patients to tests for early detection. Is this a correct response?
How do cognitive biases affect financial decisions? It turns out that this question, from the field of behavioral economics, also has a place in the world of medicine. Dr. Itai Shurtz from the Department of Economics at Ben-Gurion University of the Negev, is an applied economist whose research is based on data from health insurance funds and hospitals. In his latest economic-behavioral research - which is still ongoing and was done in collaboration with Prof. Gabriel Hudik, director of Macbeitek (the observational research arm of the Maccabi Health Services Hospital Fund) and Yoav Goldstein, a doctoral student in economics from Tel Aviv University - and with the support of the National Science Foundation, it was examined how family doctors behave after meeting a patient who is at clinical risk, and in this case - colon cancer patients.
Colon cancer is one of the most common types of cancer in Israel, and about 3,000 new patients are diagnosed with it every year. This, despite the fact that it can be detected early with a fecal occult blood test and a colonoscopy. A fecal occult blood test is included in the health basket and is recommended to be done once a year from the age of 50 to 74. Colonoscopy is an invasive test in which the lower digestive tract is examined using an endoscope (a flexible plastic tube) with a camera at the end that is inserted through the anus. It is included in the health basket only for patients with a family background of bowel cancer, who have symptoms such as changes in bowel habits and rectal bleeding or those who have had occult blood in their stool (which results from the presence of a polyp in the bowel - a benign tumor that may turn malignant).
In their study, Dr. Shortz and his partners wanted to check if the family doctor's first meeting with a patient recently diagnosed with colon cancer is a warning bell that causes him to refer more patients to colonoscopy. That is, what are the behavioral-economic consequences of this encounter. To this end, we examined data from the Maccabi Health Services Hospital Fund on colonoscopy examinations performed over four years, and on the family doctors who referred them. They compared the doctors who met with the patient relatively early in the study period (the experimental group), for example January 2013, and the doctors who met with him later (the control group), for example April 2013. This is so that the two groups are as similar as possible. It was found that in the period preceding the meeting with the patient, the trial and control doctors referred patients for colonoscopy to the same extent. In contrast, in the three months after the meeting, the experimental doctors increased the number of referrals by about 20% compared to the control doctors. With the continuation of the follow-up, which was spread over a year, the gap between the experimental doctors and the control doctors closed.
It was also found that more surprising colon cancer cases - for example, in young people or women, (who are at a relatively low risk), increased referrals for colonoscopy more. Dr. Shortz says: "We found that the lower the cancer patient's risk of the disease, the stronger the effect on the doctors' behavior was. After encountering such a case, they sent more patients for colonoscopy."
In addition, the relationship between the profile of the cancer patient and the profile of the patients who were sent for colonoscopy after meeting him was examined. It was found that if they are similar in terms of gender and age, the chance of referral to colonoscopy increases. For example, if the doctor meets with a young patient, the chance that he will refer to a young patient for examination that will follow is greater than for an older patient. "It was discovered that the characteristics of the patients referred for examination were correlated with the event, which suggests the involvement of associative memory in the doctor's response," explains Dr. Shortz.
It turns out that the lower the cancer patient's risk of the disease, the stronger the effect on doctors' behavior
The researchers wanted to further examine whether these findings indicate an excess of tests (which may cause unnecessary anxiety among patients and a waste of health system resources), or alternatively the strengthening of preventive medicine (a reminder to doctors to refer at-risk patients for testing). It was found that the increase in the number of colonoscopy examinations after the meeting with the cancer patient was not accompanied by a decrease in their positive results (presence of a polyp). That is, the rate of positive test results before and after the meeting was similar. Dr. Shortz says that "it is possible that the meeting with the patient reminded the doctors to send people at risk for a colonoscopy. Apparently, there is no reason to think that an encounter with a cancer patient would cause any reaction on the part of the family doctor, due to his experience, but it was found that it nonetheless evoked an essential, life-saving reminder."
Dr. Itai Shurtz, married with three children, lives in Mebasheret Zion.
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