Just a few weeks ago, I discussed the latest recommendations from Choosing Wisely. The goal of that initiative is to dissuade physicians from engaging in wasteful practices. Usually, and this is true of my post as well, discussions of their efforts focus on the cost savings we could achieve by ending the ordering of unnecessary tests and procedures. With health care spending so high, it only makes sense to try and reduce it in areas where we might not need it. But such discussions often ignore the very real truth that unnecessary care can often do harm. Moreover, it is often the case that patients do not know that harm is possible. This was the focus of a recent study published in JAMA Internal Medicine. In this manuscript, 286 patients who were going to have an outpatient CT scan in the Denver VAMC were asked questions about the harms of such scans. They were also asked to rate the danger from radiation from CT scans compared to MRIs or Chest radiographs. The researchers wanted to see if these patients knew that a CT scan involved a higher radiation exposure than a chest x-ray. They also wanted to see if physicians or others had discussed these risks with patients before they underwent the scans. Why is this important? About half of the ionizing radiation people in the United States are exposed to comes from imaging. The use of CT scans alone is thought to be responsible for up to 2% of cancers. The findings of this study are concerning. For the vast majority of patients (92%), this was not their first CT scan. Almost 40% had had more than 5 scans in the past. Yet only about a third of these patients reported ever having discussed the risks of a CT scan with their providers. Only 37% knew that a CT scan involved a larger radiation dose than a chest x-ray. None of them even considered the potential for inconsequential findings leading to further testing, procedures, and harm. More concerning, most of the patients felt that the decision whether to get a CT was mainly their physicians’. In other words, they relied on their physicians to tell them what was in their best interest, and those physicians decided they needed the CT scans. It’s important to recognize that this is one study of one population. But this isn’t the first time results like this have been seen. I could spend the rest of this post discussing shared decision making. That’s important, and it would likely result in patients making better – and more informed – choices about their care. I could also talk about the failure of informed consent too often in medical care. We think we’re telling patients what they need to know, but too often falling short of the mark. But instead, I’d like to take a chance to amend my prior post. Choosing Wisely did a good thing by attempting to convince doctors to order fewer unnecessary CT scans. That will result in great savings to the health care system, and that money can be put to far better uses than waste. But it’s important to remember that waste often also leads to physical and mental, as well as fiscal harm. This study , coming so soon after the release of the recommendations on CT scans, reminds us that not doing harm is out first duty. Saving money is just a bonus.