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UBC professors question effectiveness of Cold-fX

UBC professors question effectiveness of Cold-fX

November 1st, 2009  |  Published in Pilates

A pharmaceutical expert has raised questions about the scientific claims made by CV Technologies Inc. concerning its flagship product, Cold-fX, which has become Canada’s most popular cold and flu remedy.

By The Edmonton Journal February 26, 2006

VANCOUVER — A pharmaceutical expert has raised questions about the scientific claims made by CV Technologies Inc. concerning its flagship product, Cold-fX, which has become Canada’s most popular cold and flu remedy.

James McCormack, a professor at the University of B.C. faculty of pharmaceutical sciences who specializes in evaluating and interpreting clinical drug trials, said in an interview that before the public buys into the company’s motto, “trust the science,” they need to look at the science.

One key to the company’s financial success has been marketing. During the three months ending Dec. 31, it spent nearly $2.6 million, or 14 per cent of its gross revenue, on advertising and marketing. This pays for the TV, radio and newspaper ads that have made Cold-fX almost as common as colds. According to market research agency ACNielsen, Cold-fX now ranks as the country’s bestselling cold and flu remedy.

The company’s chief spokesman is Don Cherry, famous for his flashy suits and bombastic pronouncements. To leaven his patter, the company adds the tag line, “Trust the science.”

At the Vancouver Sun’s request, McCormack and a colleague, Peter Loewen, an associate professor at UBC’s faculty of pharmaceutical sciences, reviewed the company’s last three clinical trials. In all three trials, the researchers were not able to show that Cold-fX statistically reduced the percentage of subjects who ended up getting a cold.

The first two trials were conducted in 2000 and 2001, and involved 198 nursing home residents with an average age of about 82. Roughly half were given the ginseng extract used in Cold-fX and half a placebo.

The main purpose of these studies was to see whether the ginseng extract would reduce the incidence of acute respiratory illnesses (flu and respiratory syncytial virus, or RSV, a virus that causes flu-like symptoms), as defined by subjective symptoms such as cough, sore throat and runny nose. The researchers, reporting the results in the Journal of the American Geriatrics Society, found “no significant difference between the placebo and the ( Cold-fX) groups for the number of (acute respiratory illnesses) defined by symptoms.” They also found “no significant difference in the severity or duration of symptoms related to (acute respiratory illnesses) between the two groups in either study.”

The secondary purpose of the studies was to measure the difference in the incidence of laboratory-confirmed (typically by a viral culture) acute respiratory illnesses between the two groups. In the placebo groups, six and 12 per cent of the subjects in the two studies contracted flu or respiratory syncytial virus. In the ginseng groups, these percentages were lower — zero and two per cent — which suggests the ginseng had some therapeutic benefit. However, in each case, the “p value” — the probability that chance explained the difference — was high enough that these differences, by the researchers’ own admission, were not deemed statistically significant.

It was only by combining the two studies that the result (nine per cent for the placebo groups versus one per cent for the ginseng groups) became statistically significant.

McCormack says combining the two studies erodes the credibility of the results: “Taking two studies that don’t show a benefit and then adding them together to get a positive result is a form of data mining. It’s torturing the data until it confesses.”

He says these results are “hypothesis generating,” meaning they raise a theory that may be worth investigating, “but they are not definitive evidence that Cold-fX works.”

Company president, CEO and chief scientific officer Jacqueline Shan insists that combining the two studies is a well-recognized and often-used procedure. “If it wasn’t a legitimate procedure it would never have been accepted for publication by the Journal of the American Geriatrics Society.”

Loewen agrees that combining studies is a well-accepted process and does not constitute “data-mining” as long as it has been pre-planned: “Otherwise, it comes down to the trickier question as to whether the researchers did a second study because they didn’t like the initial results.”

Shan said the company decided to conduct a second trial, not because it didn’t like the initial results, but because it ran into a logistical problem: “The number of naturally occurring illnesses during the first season was deemed to be insufficient to be able to perform any meaningful analysis, therefore, a second trial was performed. It is the pooled analysis of these two studies that provides the meaningful results,” she said.

Taking the combined figures at face value, the absolute reduction in laboratory-confirmed illness was eight percentage points (from nine per cent to one per cent). But on a relative basis, the reduction was a much more impressive-sounding 89 per cent (the eight-per-cent reduction divided by the nine-per-cent starting figure). Using this relative figure, the company boasted that “Cold-fX reduces the risk of colds, flu and respiratory illness by 89 per cent,” a statement that both Loewen and McCormack dismiss as “technically accurate, but quite misleading.”

Loewen notes that, contrary to the company’s claim, the two studies showed that Cold-fX didn’t reduce the effects of acute respiratory illnesses, as measured by symptoms. He says this point is critical: “The patient has no interest in, or knowledge of, whether their illness is laboratory-confirmed or not. They don’t care and we don’t look for that in clinical practice. The study showed no difference in feeling sick, which was the primary endpoint.”

He also noted that some 36 per cent of nursing-home residents reported symptoms of cold or flu, of which only nine per cent, or one-quarter, were laboratory confirmed. It was this reduction in laboratory-confirmed illnesses that became the key outcome.

“What about those other three-quarters of people who, for all intents and purposes, got sick? Are we to say that because their illnesses were not laboratory-confirmed, it wasn’t relevant to them?” he asks. “Well, of course it was. That’s why they (the researchers) picked symptoms-based outcomes as their endpoint. They could have said, ‘Our interest is only laboratory-confirmed illnesses,’ but they knew the clinically relevant endpoint was clinically diagnosed illnesses.”

Shan argues that finding a reduction in laboratory-confirmed cases is “more powerful” than finding a reduction in cases defined by symptoms alone. She notes that people can easily mistake allergy symptoms, for example, for cold symptoms, but with laboratory confirmation “we cannot mistake the condition experienced by the patient for any condition other than a true acute respiratory illness.”

Shan says that relative risk reductions are commonly used to quantify the efficacy of anti-viral drugs. In any event, she says, both relative and absolute risk reductions figures were reported in the company’s news release.

McCormack also notes the incidence of laboratory-confirmed illnesses in both the placebo and ginseng groups is relatively small (nine per cent and one per cent), which means that Cold-fX, even if it does work, would be a questionable expenditure for most people.

“Based on these results, 13 nursing-home patients would have to take Cold-fX for two to three months to prevent one case of a laboratory-confirmed flu or RSV,” he calculates.

For an herbal-based cold remedy, Cold-fX is expensive. Bottles of 180 capsules are selling at Costco for $57, or about 36 cents per capsule. The recommended dosage is two capsules per day, so if 13 subjects took the recommended dosage for two and half months, the cost would be $702. In other words, 13 nursing-home residents would have to spend $702 to prevent just one case of laboratory-confirmed flu.

“The increasing sales of Cold-fX indicate many people find it works for them,” Shan says. “They make the economic judgment that the benefits of disease prevention outweigh the associated costs.”

She also stated in a news release that “the increased public demand for our products is proof of the power of prevention.”

But McCormack says high demand for Cold-fX proves only that the product is popular, not that it works: “Nobody who takes Cold-fX will be able to tell if it works for them. That’s because colds occur randomly and symptoms vary in their severity. Who can say for sure that they didn’t get a cold because of a particular product, or that their cold symptoms were moderated because of that product?”

Assume, for example, that one-third of the populace gets a cold every year. Assume also that the entire populace is given a placebo masquerading as a cold remedy. Obviously one-third of the population will still get a cold.

“Even though the placebo didn’t reduce the number of colds, the two-thirds who didn’t get a cold will swear by it,” McCormack notes. “That is one of the many problems with anecdotal observation.”

In October 2005, the company released the results of another clinical trial led by Dr. Tapan Basu, then a professor in the University of Alberta’s faculty of agricultural, food and nutritional sciences, and Dr. Gerald Predy, Edmonton’s chief medical health officer. This study consisted of 279 subjects, half of whom were given the ginseng extract used in Cold-fX and half a placebo. The main purpose was to see whether the ginseng group caught fewer colds.

Over a four-month period, subjects in the ginseng group experienced, on average, one-quarter of a cold less than the placebo group. That means each person has to spend a total of $86 to prevent one-quarter of a cold.

Recognizing that more studies are needed, the company is now funding a much larger study involving 720 subjects in three cities, Toronto, Edmonton and Vancouver. The subjects are all over 65 and were previously vaccinated against flu. The purpose is to see whether Cold-fX can prevent laboratory-confirmed flu and cold viruses, and alleviate the severity and length of symptoms.

Shan said the clinical trial, which could have an impact on Cold-fX’s future sales, is still in its early stages. No release date has been set.

© CanWest MediaWorks Publications Inc.

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