Cold Remedies Should Provide “Accurate Description” Of Benefits – Study

Consumers of common cold remedies believe the treatments should reduce the severity or duration of their ailments more effectively than they actually do, according to an Annals of Family Medicine study.

In order to justify the costs and risks associated with their use, cold treatments should reduce overall illness severity by 25 to 57 percent, according to respondents in the study by Dr. Bruce Barrett, a professor in the University of Wisconsin's Department of Family Medicine, et al.

However, four popular cold treatments - vitamin C, echinacea, zinc lozenges and the unlicensed antiviral pleconaril - do not provide that level of reduction, Barrett, et al. noted in the May/June AFM issue.

The study evaluated responses based on the concept of sufficiently important difference, or the smallest benefit a treatment would require for consumers to justify costs and risks associated with its use.

Then participants were presented four treatment descriptions, but not the name of each treatment.

The researchers found treatment based on vitamin C received the most favorable ratings, with a mean severity benefit SID of 24.6 percent. The method based on echinacea yielded a mean SID of 31.9 percent.

Treatment with zinc lozenges resulted in a mean SID of 46.9 percent, while the antiviral scenario had a mean SID for severity benefit value of 57.2 percent.

The results emphasize the importance of providing consumers with "an accurate description of expected benefits, costs and risk of harm" associated with cold treatments, the researchers said.

"There have been too few investigations into health values in general and into the nature of clinical significance in particular," they said, adding "medical decision making ... is inextricably linked to these conceptual entities."

Conducted between May 2003 and August 2005, the study assessed 253 participants' opinions on the benefit/harm trade-off of the four cold treatments.

The participants comprised 162 people contacted by telephone and 91 contacted in person, with each experiencing cold symptoms at the time.

Consumers were asked how much of a benefit they would expect from each treatment in the form of "reduced severity and/or decreased duration of illness." They were also provided the costs and risks of each treatment.

After each scenario was presented, participants were asked whether they would take the treatment, and to explain their choice. Then they were asked if they would take the treatment if it reduced severity of symptoms by various percentages.

Barrett et al. said while some people will take a treatment regardless of benefit and others will not even when hypothetical benefits are large, the majority of consumers "require a certain amount of benefit to justify costs and risks, which makes sense and fits with both clinical experience and psychological theory."

"People are (somewhat) rational, and make choices based on perceived likelihood and magnitude of both positively and negatively valued outcomes, but since different people value health-related domains differently, there is diversity in SID magnitudes across populations," the researchers added.

However, they said "when benefits and harms are made explicit and portrayed in simple language, population distributions of SID are characteristic, reproducible, and largely unaffected by age, sex, ethnicity, income, education and severity of illness at time of interview."

The study represents the second phase of the researchers' benefit-harm trade-off interviews aimed at assessing SID of the common cold. In the first study, completed in 2005, reduction in duration of illness was the primary benefit under investigation. The studies yielded similar results, with the vitamin requiring the least benefit to justify treatment and the prescription pill the most benefit.

The American College of Chest Physicians in January 2006 revised its guidelines to advise the only effective OTC treatments for acute cough due to the common cold are older antihistamine/decongestant products (¹ (Also see "Most OTC Cough Meds Dismissed By Chest Physicians Guidelines" - Pink Sheet, 16 Jan, 2006.), p. 4).

In July 2005, a New England Journal of Medicine study showed neither pre-emptive nor early treatment with echinacea prevents the common cold or reduces the severity of its symptoms (² (Also see "Echinacea Ineffective For Cold Prevention, Treatment – NEJM Study" - Pink Sheet, 1 Aug, 2005.), p. 13).

- Eileen Francis ([email protected])