The story could have benefited from some strong, independent voices commenting on the findings and from a more careful explanation of the study itself. Readers deserved to know more about the study’s limitations, about the absolute differences seen in the groups studied and about the risks associated with statin use. The story went beyond the press release used to promote the study, but it needed to go much further in helping readers understand the strength of the findings and their potential impact on readers considering surgery.
One of the risks associated with surgery is kidney failure, an outcome no patient or surgeon wants. To be able to reduce that risk by taking a pill would be a major boon to medicine. This study hints that statins could provide that benefit, but, as the authors themselves acknowledge, there are significant limitations to a backward-looking, uncontrolled study. Those limitations and the reality of the necessary steps to create a foundation for solid clinical practice needed to be acknowledged in this story and other coverage of the same topic.
The story makes no mention of costs, even though the costs of statins are easy to find, and, in Canada, because of the universal health care system, the costs of statins to the government should be an easy number to quantify.
All benefits are presented in relative terms, which is misleading to readers. For example, the third sentence says, “Researchers found that people who took statin medications had about a 16% reduced risk of renal failure and a 21% lower risk of dying after their surgeries, compared to people who weren’t taking the drugs.” What are the absolute numbers? Well, out of 67,941 people, 1,208 people suffered an acute kidney injury while not taking statins, and 1,039 suffered one while taking statins. That means 169 fewer people suffered an acute kidney injury, and this is making the big assumption that statins had anything to do with it.
No risks or harms from statins are mentioned in this story. Statins are a well tolerated class of drugs with a relatively low risk profile, but all drugs carry risks and have side effects. When you start talking about extending statin use to a much larger percentage of the population, those risks become magnified. We felt that some mention of risks was warranted.
There is some good information in here about the basic outlines of the study design. The story says, for example, “For the study, researchers looked at the medical records of all seniors who had elective surgery in Ontario, Canada, from 1995 through 2008, a group of 213,347 men and women over age 65. Elective procedures included heart or lung operations, vascular surgery, or surgery in the abdomen, or procedures on the bladder, ureter, or kidneys — except transplants or removal of the kidneys. About half of patients in the study had heart surgeries. Nearly one-third of these patients were taking statin medications before going under the knife.”
What was missing was any sense of the limitation of these findings. The study itself goes on at some length about these limitations, including this crucial piece of information: “As with all observational studies, the protective association seen between statin use and AKI may not be causal.” We also thought it worth noting that to be considered a “statin user,” all one had to do was fill a statin prescription in the previous 90 days. Given that someone could have filled a statin prescription on Monday and had surgery on Friday, we don’t think this is a strong enough basis to prove that statins protected kidneys from failing.
We don’t think the story intended to engage in disease-mongering, but the story is framed in such a way that the risk of renal failure following surgery is overly hyped. The second sentence of the story says, “For reasons doctors don’t completely understand, this complication, which is called acute kidney injury (AKI) or acute renal failure, is on the rise, and it dramatically increases a patient’s risk of dying during recovery.” It isn’t until later in the story that we are told, “Overall, about 2% of patients experienced renal failure within two weeks of their procedures.” That should ease patients’ concerns a bit until later in the story it says, “Depending on how researchers define it, studies have shown that it may occur in up to 40% of patients.” This sort of whipsawing can turn readers off to a topic and leave them feeling scared and confused.
There are no independent sources quoted in this story.
There was nothing in the story about current treatment approaches for reducing the risk of renal failure. This leads readers to believe that there is nothing they can do to prevent a renal injury or death other than take statins.
Statins are such a widely prescribed class of drug that we feel most readers will understand their availability. The story does hint at this by noting that one-third of the patients who had surgery in this study were taking statins.
The story, like the study, points out that the connection between statin use and renal protection has only been seen in animals. We think the story makes it clear to readers that what’s new and important here is showing a relationship in humans as well.
The story does not rely solely on a news release, but we do think the story relied too heavily on the study’s abstract. It should have gone deeper into the story to provide readers context.