nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
See here for more discussion.

Tuesday, December 21, 2010

STUDY: Echinacea Effective For The Common Cold? Depends On Whether You're A Believer

 
As expected, this randomized study showed no benefit, but what's fascinating is the opinions of the investigators involved.

For the herbally uninformed, echinacea is a best-selling over-the-counter botanical that is marketed to boost immunity...to the tune of about $10 for 60 capsules.

The study is available here (Annals of Int Med, Dec 20).  A typical news story describing it can be found here (Assoc Press, Dec 20).

Using your taxpayer dollars, the investigators, led by Dr. Bruce Barrett at the University of Wisconsin, randomized over 700 adults and children to echinacea in a standard dose versus placebo over five days (there was also a no-treatment control group).  It's reportedly the largest randomized study done so far.  The data showed no statistically significant difference in severity symptoms or duration of illness.

However,
"Barrett and other experts said the findings would probably be viewed as positive by echinacea supporters but as the "nail in the coffin" by critics."
By contrast, the executive director of the American Botanical Council, Mark Blumenthal, while admitting the study was well designed, "used a good quality product at a reasonable dosage and tested echinacea in a real-world settings" said,
"It's not a compelling result in either direction,"
You be the judge:

For Onion Peelers,
Of the 719 patients enrolled, 713 completed the protocol. Mean age was 33.7 years, 64% were female, and 88% were white. A comparison of the 2 blinded groups showed a 28-point trend (95% CI, -69 to 13 points) toward [symptom] benefit for echinacea (P = 0.089). Mean illness duration in the blinded and unblinded echinacea groups was 6.34 and 6.76 days, respectively, compared with 6.87 days in the blinded placebo group and 7.03 days in the no-pill group. A comparison of the blinded groups showed a nonsignificant 0.53-day (CI, 1.25 to 0.19 days) benefit (P = 0.075). Median change in interleukin-8 levels and neutrophil counts were also not statistically significant (30 ng/L and 1 cell/high-power field [hpf] in the no-pill group, 39 ng/L and 1 cell/hpf in the blinded placebo group, 58ng/L and 2 cells/hpf in the blinded echinacea group, and 70 ng/L and 1 cell/hpf in the open-label echinacea group).
 
If you read all that stuff, you may be thinking, "Wait.  You said no difference, but the above says symptom "benefit." "  Fair enough.  But look further.  The sentence says a "trend," not a difference.  The clue to this language is in the Confidence Interval  (see the "CI").  It runs from -69 to +13.  This means the variation ranged both sides of zero:  69 "symptom" points better (a scale made by assigning points to all the symptoms of sneezing, congestion, sore throat, etc) to 13 symptoms points more (i.e., worse).
 
Not convincing.
 
And that's why the herbal supporters will maintain their belief that the product works.
 
I think it's a waste of money.  But you can pick whichever belief you feel most comfortable with.
 
Doc D
 
 

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