Posted in Disease Prevention, FDA, Government Regulations, outcomes, Patient Safety, Policy Issues, Uncategorized, Unsettled Science

Is the Sunscreen Scare Legitimate?

But just because something gets into your body doesn’t mean it’s bad for you. I know these compounds have chemical names, but the assumption that artificial compounds are worse for you than all of the other stuff we put in our bodies is known as the “naturalistic fallacy.” By way of comparison, the average blood level of caffeine after a cup of coffee is 50 times higher than the peak concentration of oxybenzone seen in this study. But that oxybenzone level is about seven times higher than the blood nicotine level seen after smoking a cigarette.

In other words, the fact that you can measure something in the blood doesn’t tell you anything about whether it is bad for you. We simply don’t know what the risk is. And we need to find out.

Personally, I wouldn’t call for a freeze on chemical sunscreens. These drugs have been used for decades and there have been no strong epidemiologic signals of harm. Quite the opposite, they have probably prevented uncounted cases of skin cancer.

The problem with studies like these is that the fear they engender may do more harm than the good science that results from them. Nothing has changed about the harm of UV rays since the publication of this study in JAMA; you still don’t want your skin exposed to them.

Posted in Disease Prevention, Education, Evidence-based Medicine, Nutrition, outcomes measurement, Patient Safety, Prevention, Uncategorized

The Probiotics Trend: Should We Be All In or Call Time Out?

Whoa!!! Let’s slow down the probiotic wagon train!

1) Researchers began by giving probiotics to germ-free mice, in which they were actually able to induce the desired microbial changes. When they gave the probiotics to mice that were already colonized with their own innate bacteria, however, there were evident resistance patterns. They were not able to induce the colonization that they thought they would when they gave the probiotic. The same effect was evident when they tested it in humans. There seems to be certain bacterial resistant patterns in hosts that either facilitate or block the colonization intended by this probiotic effect.

2) Researchers found that there was a rapid reconstitution of the normal biome when they gave the patients their pre-antibiotic stool back. Comparatively, the use of probiotics was associated with a marked delay in patients being able to return to what their normal microbiome was before antibiotics.

3) Nearly a third or more of all trials included reported no adverse event monitoring or harm, whereas 98% provided no adequate documentation, validation, or standardization in reporting adverse events or serious adverse events. Given the high variability in the quality of existing data, the authors concluded that it may be too premature to make any broad conclusions about the safety of these interventions.

Certainly, just like any other medication, potential harm needs to be assessed in probiotics.

Source: The Probiotics Trend: Should We Be All In or Call Time Out?

Posted in Education, Evidence-based Medicine, outcomes measurement, Patient Safety, Policy Issues, Quality, Uncategorized, Unsettled Science

Irreproducible ‘Scientific’ Results

The reliability of evidence-based medical care depends on validation of original research. Let’s start encouraging and incentivizing investigators to verify (or refute) heretofore non-reproduced studies; while simultaneously discouraging primacy signalling with impact factors such as prestige of the institution.

Posted in Capers, CDC, Evidence-based Medicine, FDA, Government Regulations, Influence peddling, NIH, Patient Safety, Policy Issues, Unsettled Science

Behind the Veil: Conflicts of Interest and Fraud in Medical Research

Chris Kresser

If there is a violation, the FDA classifies it in one of two ways: Voluntary action indicated (VAI) means the inspectors have found violations, but the problems aren’t serious enough to require sanction.  Official action indicated (OAI) means that the inspectors have found violations significant enough to warrant official action.

Siefe and his assistants used the Freedom of Information Act to request information from the FDA, and supplemented that data with Google searches of the FDA database. They found 57 clinical trials that were directly linked to an OAI inspection.

The misconduct identified by the FDA in these cases included:

  • Falsification or submission of false information
  • Underreporting of adverse events
  • Failure to follow the investigational plan or other violations of protocol
  • Inadequate record keeping
  • Failure to protect the rights, safety, and welfare of patients
  • Use of experimental compounds in patients not enrolled in trials
  • Failure to supervise clinical investigations properlyThe 57 trials Seife identified were in turn linked to 78 research articles published in the peer-reviewed scientific literature. 96 percent of these articles failed to mention the violations identified by the FDA inspection—despite the fact that in the majority of cases the inspection was completed at least 6 months before the article was published.

via Behind the Veil: Conflicts of Interest and Fraud in Medical Research.

Posted in Technology, Uncategorized, Unsettled Science

Why Is So Much of the Medical Literature Wrong?

In 2005, John Ioannidis published a review of 45 highlighted studies in major medical journals. He found that 24% were never replicated, 16% were contradicted by subsequent research, and another 16% were shown to have smaller effect sizes than originally reported. Less than half 44% were truly replicated.

Consider a situation in which 10% of all hypotheses are actually true. Now consider that most studies have a type 1 error rate (the probability of claiming an association when none exists [ie, a false positive]) of 5% and a type 2 error rate (the probability of claiming there is no association when one actually exists [ie, a false negative)] of 20%, which are the standard error rates presumed by most clinical trials. This allows us to create the following 2×2 table.

This would imply that of the 125 studies with a positive finding, only 80/125 or 64% are true. Therefore, one third of statistically significant findings are false positives purely by random chance. That assumes, of course, that there is no bias in the studies, which we will deal with presently.

Bias: Coffee, Cellphones, and Chocolate

Bias occurs when there is no real association between X and Y, but one is manufactured because of the way we conducted our study. Delgado-Rodriguez and Llorca[4] identified 74 types of bias in their glossary of the most common biases, which can be broadly categorized into 2 main types: selection bias and information bias.

One classic example of selection bias occurred in 1981 with a NEJM study showing an association between coffee consumption and pancreatic cancer.[15] The selection bias occurred when the controls were recruited for the study. The control group had a high incidence ofpeptic ulcer disease, and so as not to worsen their symptoms, they drank little coffee. Thus, the association between coffee and cancer was artificially created because the control group was fundamentally different from the general population in terms of their coffee consumption. When the study was repeated with proper controls, no effect was seen.[16]

via Why Is So Much of the Medical Literature Wrong?.