Does health screening lead to over diagnosis?

Some doctors and healthcare professionals have come to believe that there is too much preventative care going on.

Is preventive screening resulting in the overdiagnosis of diseases and the overtreatment of those diseases? They argue that we are spending too much money on preventative testing and screening methods. This is in direct opposition to the belief that early diagnosis of disease saves both money and lives. In fact, in some countries, health care reform is based on doing more screening instead of less screening.

Those who believe we are doing too much screening believe that some preventative care does reduce costs but in most cases, it does not. The costs are not reduced but are instead shifted. Take the example of early cholesterol screening. A person may be on expensive cholesterol medication for decades and may still have a heart attack. The cost of repetitive re-checking of the cholesterol needs to be considered in the cost of preventative care along with the cost of the medication. To be sure, a heart attack is costly but you can still get a heart attack when on cholesterol medication and it isn’t certain how many patients are completely protected from having a heart attack.

There are two parts to preventative care: the first is screening and the second is treatment. Billions of dollars are spent on screening of people at risk for a disease and only a few become at risk for the disease. This means billions of dollars are spent on healthy people. Those who have the disease or are at risk for the disease (like cholesterol elevations) are treated to the tune of many billions of more dollars spent. This means that screening needs to be done on people who are at the highest risk for diseases and not on everyone. Screening creates anxiety in patients who worry over the outcome of the testing, especially if the screening test is equivocal and a more invasive test needs to be done in order to define whether or not the patient has the disease.

Consider also the PSA test. If it is high, men need to have prostate biopsies, which are expensive and anxiety-provoking. Many of those individuals will have a negative biopsy or will have a slow growing cancer that does not need to be treated.

The tendency has been to screen for lesser and lesser abnormalities and to test for them further apart. Unfortunately, this has been compared to professionals decreasing the threshold for finding disease. In the case of cholesterol, the upper limits of testing for excessive cholesterol dropped from 240 to 200 so that even more patients are thrown into the loop of having “high cholesterol”.

The answer to all of this is unclear. It may mean we screen less or keep with the status quo and test patients for diseases regardless of cost.