The Controversy of CT Scan as a Prevention Intervention

By: Nirmala Trisna Anak Agung Istri
(for PH7530 - Spring 2005, Dr. Paul G. Farnham, Institute of Public Health, Georgia State University)

Medical technology has been developing rapidly in order to achieve better health outcomes. One of the important breakthroughs is a computed axial tomography (CAT or CT) scan, which is used to help physicians examine and determine a certain illness in one’s body without doing any surgery. This paper describes the current controversy of CT scan as a prevention intervention, in relations to the effectiveness, the cost of intervention, and its effects on behavior of health care providers, patients, and health insurance. At the end, CT scan controversy is compared with the issue of meningitis vaccination as a preventive intervention program for college students in the U.S.

The CT scan controversy. CT scan emerged in 1970s as a superior version of traditional X-rays, which can show cross-sectional images of an entire body region, highlighting the precise location of certain abnormalities (1). Recently, there are two different opinions regarding the usage of CT scans. First, the conventional thought that CT scan is an effective diagnose tool for patient who has been injured or shows specific symptoms. It is a valuable aid to help physicians examine the patients’ health and prescribe any responding treatments. Second, the new thought that has brought controversy, said that CT scan is the most credible way to provide assurance on patients’ health condition. The CT scan on healthy people, or CT screening, gives more thorough results than regular physical examination on how exactly the person’s health condition is. The proponents of CT screening said that CT scan is a new technology for a better future of medical field as it can detects any incipient disease before significant symptoms occur. It would be an interesting experience to see the person’s organs on screen and to find any abnormalities. The image results of CT scan can also be a motivating tool for people to live a healthy life style.

The issues of CT scan efficacy and specificity are reasons why the major stakeholders in health industry oppose its usage on healthy people. No health insurance covers the cost of doing CT scan on healthy people. The U.S. Food and Drug Administration (FDA) stated that there is no data demonstrating that whole-body CT screening is effective in detecting any particular disease early enough for the disease to be managed, treated, or cured and advantageously spare a person at least some of the detriment associated with serious illness or premature death (2). The specificity of the screening itself is low as CT scan has high probability of false positive results when applied to the general population. Healthy individuals can turn into patients; they have to follow further unnecessary and potentially dangerous scans and treatment. If the screening found problems, which cannot be ignored, insurance companies would pay for further required exploratory procedures. Yet, the CT scan finding itself can be ambiguous. It really depends on the radiologist and physicians to determine such finding needs to be further examined or not.

It is unjustifiable that the benefits of CT screening for those few who took the advantage outweigh the total cost. According to Dr. Black at Dartmouth, there would be a large amount of over-treatment in the population, which could cause more harm than good (1). Estimation on how long this early detection can lengthen one’s life years is unknown. Even early detection indeed can extend individual’s life years, the next issue will be whether the extra life years give benefits to the individual. The benefit should be compared with potential risk of cancer due to radiation exposure and suffering due to extensive follow up procedures.

The CT screening opponents’ concern is also about the negative result. Knowing there are no abnormalities in the body, an individual might fail to maintain a healthy life style. Should a person decide to undergo CT screening, this issue should be understood as well as the risk from radiation exposures. According to the study from Columbia University in New York, radiation dose from a full-body CT scan can be almost as high as the dose received by the survivors of the 1945 atomic bombings of Hiroshima and Nagasaki. Despite the study limitations on sampling bias and the inexistence data on accurate estimate of CT scan radiation dose, the exposure from even a single full-body CT scan is not minor. Other suggestion was from Max Rosen of Harvard Medical School who said that potential harm on individuals can be reduced if CT screening is tailored to the individual’s medical history, not from the perspective of population (3).

The CT scan cost and its effect to the behavior of health care stakeholders. CT scan is not a cheap procedure that can be universally accessed. The machines cost about $1 million and the price of one CT scan procedure is $700 - $1,500 (3). Because of the high cost and no insurance reimbursement, CT scan providers conduct direct marketing to consumers also to physicians persuading them the benefit of early screening. It turned out that the U.S. Army spent $1 million in 2000 to provide preventive screening for 4,000 soldiers as part of routine physicals and the union representing Los Angeles Police officers had arranged for a discounted rate for its healthy members to get a scan (1).

In accordance with FDA regulation, health insurance does not cover CT scan on a preventive basis. They will not provide reimbursement for CT scan cost without physician’s referral. Yet, there has been thousands of people with no symptoms of disease took CT screening, even without the knowledge of their primary physicians (3). They are willing to dig their own pocket because they believe the benefit of early detection will outweigh the cost.

In the earlier days, many physicians consortium bought the machines and they had started to refer patients for the tests and earning profits from each. Because of that, some states passed laws prohibiting hospitals or medical centers from buying CT scan machines without first demonstrating need (1). The CT scan market has experienced rapid rise and fall (4). Because of the profit-driven health care providers, there has been growth in numbers of facilities performing full-body CT scan. Many people believes the advantage of having CT screening, result of massive direct marketing from health care providers which have stakes in CT scan, so they are willing to pay from their own pocket. Yet, the power of dissuasion by professional societies and the refusal of health insurance to reimburse the high cost could reduce the demand for CT screening, thus lessen the numbers of CT scan providers in the market.

The controversy comparison. The controversy of CT scan is different from meningitis vaccinations for college students in the U.S. Each prevention intervention has different target population and nature of disease being prevented. CT scan, which is primarily for individuals with certain symptoms, has started to be undergone and privately paid by healthy individuals. The efficacy and specificity of CT screening are unknown, thus has created debates on both proponents and opponents. On the other hand, the meningitis vaccination program issues are on how much government should spend on the expensive latest vaccines and how to have population at risk (in this case, the children) take the vaccines (5). CT screening is a private good that the individuals can measure the impact of doing an early prevention, whereas meningitis vaccinations for college students have positive externalities to the society. As meningococcal disease is contagious and can kill healthy teenagers within hours, early prevention intervention has wider impact to the society. The burden of meningococcal disease is high due to lost of generation and productivity compared to any asymptomatic disease detected by CT scan, which its malignancy is actually unknown. These facts lead to the importance of government role to regulate and finance the vaccination program of meningococcal.

Because of the prevention intervention efficacy, government provides different recommendations for CT scan and meningitis vaccinations. The Centers for Disease Control and Prevention recommended vaccinations for college students and the vaccine is safe and efficacious to reduce the risk for meningococcal disease (6). For CT scan, the FDA knows of no scientific evidence demonstrating that whole-body scanning of individuals without symptoms provides more benefit than harm to people being screened, also prohibits manufacturers of CT systems to promote their use for whole-body screening of asymptomatic people.

There is also issue beyond medical treatment from the providers due to the expensive investment. CT scan providers put efforts to persuade people to use CT scan even without physician’s referral or directly do marketing to physicians to provide referrals in order to obtain return on their investment. For the vaccines manufacturers, it is not easy to persuade people to take shots for meningitis disease without government regulation, so they have to rely on government and private insurance to finance the vaccines.

References:

1. Spurgeon, Devon and Burton, Thomas M. Using the CAT scan as a Checkup Device?. The Wall Street Journal; March 23, 2000.

2. Center for Devices and Radiological Health. Whole Body Scanning Using Computed Tomography (CT). U.S. Food and Drug Administration. Date retrieved: February 2, 2005. http://www.fda.gov/cdrh/ct/index.html

3. Windham, Christopher. Study Warns of CT Scans’ Risk. The Wall Street Journal; August 31, 2004.

4. Kolata, Gina. Rapid Rise and Fall for Body-Scanning Clinics. The New York Times; January 23, 2005.

5. Harris, Gardiner. Panel Reviews New Vaccine that Could Be Controversial. The New York Times; October 27, 2004.

6. Centers for Disease Control and Prevention. Meningococcal Disease and College Students, Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recommendations and Reports 2000; 49 (RR07): 11-20.