And why is this a topic for the math blog? We define under, over, middle and similar terms on the first day in Kindergarten; these are fundamental concepts in math education.
It turns out the researchers defined their terms like this:
- underuse is the lack of providing necessary care
- misuse is the provision of wrong care or medical error
- overuse is using medical services with no benefit or where harm outweighs benefit
Misuse includes unnecessary procedures, incorrect medication or gross error.
The researchers identified 172 articles from 1978 to 2009 that measured the rates of overuse of procedures (53 studies), diagnostic tests (38 studies) and medications (81 studies), then examined the use of 18 therapeutic procedures and 24 diagnostic services.
For preventive services, overuse rates ranged from 7% to 61%. Cancer screening overuse varied from 8% to 61% for screening colonoscopies. Prostate cancer screening using PSA was 16% to 36%. Cervical cancer screening reported that 58% of those screened should not have been. The overuse rate of mammography diagnosis was reported to be 30%.
For medications, antibiotics for upper respiratory tract infections (URI) were the most commonly studied. The overuse rates for antibiotics for URI ranged from 2% to 89%.
What's the harm in testing a bit too often? Won't we find problems sooner?
Not necessarily - there are significant risks:
- Risks directly related to the test, such as the radiation exposure caused by imaging tests
- Risk of a false positive, leading to mental anguish and unnecessary follow-up tests and procedures, each with its own set of health hazards
- Risk that a condition will be identified that is not harmful but now will be treated
Although there are enormous costs associated with overuse (estimated as high as $200 billion a year, or 10% of total healthcare expenditures), there are also personal costs. Remember, testing is a very specific and personal matter. Some patients want to be absolutely sure; others can live with less information (what I don't know won't hurt me). There are no hard-and-fast rules for which tests are needed in each situation.
The reasons and motives for under- and over-utilization are murky. Liability and malpractice suits drive doctors to do more tests, for example, as does peer pressure among patients (Have you have a body scan yet, darling?). We really don't understand our medical system well at all, as the following quote indicates:
What is most striking about this report is how hard the authors searched for data on overuse of health care and how little they found. They reviewed 21 years of the medical literature and evaluated 114,831 publications, yet found only 172 articles that addressed overuse of health care. If we are to improve health care in the United States, we must know as much about overuse of health care as we do about underuse of health care. This article gets us started.
Sadly, there is no international, national or regional correlation between outlays of money, procedures and testing, and longevity or quality of life. [click on the map to enlarge]