This article was originally posted in the Montreal Gazette.
One of the great problems in medicine is the issue of over-testing. It is tempting to assume that doing more tests results in better outcomes: that by testing more broadly, one can pick up previously missed diseases and can treat people earlier. As well, human beings are naturally inclined to favour “doing something” over doing nothing.
But, in reality, there are very few circumstances where regular testing serves a purpose in the absence of symptoms. There are certain cancer-screening programs — most notably, cervical screening with PAP tests and colon cancer screening with either colonoscopies or other tests to detect blood in the stool — that have a demonstrated benefit. Also, checking people for high blood pressure or high cholesterol after a certain age has value, because these produce no obvious symptoms and treatment prevents heart attacks.
But many tests do not really have much value when we evaluate them objectively. Such groups as Choosing Wisely have devoted themselves to speaking out against testing that has little medical value and just drains resources from the system. For example, they recommend not sending patients with low back pain for X-rays unless there is some reason to suspect a severe problem. Most low back pain is muscular, while X-rays can only detect bony pathology. They oppose routinely prescribing antibiotics for probable viral infections because antibiotics only work against bacteria. They advise against regular chest X-rays and ECGs in low-risk patients because they are frankly low-yield tests that add little real value in most cases.
Understandably, when patients have some issue, they want to go for some sort of test. People obviously feel better when they get back negative results, but the downside of all this excessive testing is added health-care costs with no improvement in outcome.
One of the many culprits is vitamin D testing. Contrary to popular belief, vitamin D deficiency is not the cause of every disease under the sun, and taking vitamin D supplements does not reduce your risk of either heart disease or cancer. Similarly, the data to date show no benefit as a COVID-19 treatment.
But testing vitamin D levels in the blood remains a common and expensive test. Most people do not realize how expensive blood tests are and how much money could be saved if we reduced the unnecessary ones. A vitamin D test costs about $20 to $40. When multiplied across the whole population, that translates into a significant expenditure.
Unfortunately, change is hard. Public awareness campaigns and education have some modest effects on reducing unnecessary testing, but for many sorts of tests, it remains rampant. An initiative in Alberta suggests how to address the issue. Alberta Health Services established a criteria-based approach for vitamin D testing and would only run tests if the ordering physician indicated that the patient had a metabolic bone disease, abnormal calcium levels, a malabsorption syndrome, chronic kidney disease, or liver diseases. In these circumstances, someone could indeed develop a vitamin D deficiency, and testing in this patient population would be in keeping with current guidelines.
In the nine months before making the change, Alberta saw more than 250,000 vitamin D tests ordered. In the nine months after, that number fell to just over 20,000, a 92% decrease that translated into a savings of $4 million annually. If we could apply similar algorithms to the many other tests of dubious clinical value, we could drastically reduce healthcare expenditures without affecting patients’ health.
While we often think of healthcare as free in this country, the reality is that we do pay for it. We just pay for it out of the public purse, and money spent on unnecessary testing is not available to spend on something else.