A new study released by the Agency for Healthcare Research and Quality (AHRQ) concludes that evidence of benefit is lacking for many common ways of treating osteoarthritis of the knee, including popular dietary supplement ingredients, a common surgical procedure, and injected preparations.

The review found that glucosamine and chondroitin appear to be no more effective than placebos in relieving knee pain caused by osteoarthritis.

“Millions of Americans seek relief from the pain and reduced mobility caused by osteoarthritis of the knee,” said AHRQ director Carolyn Clancy, MD. “However, they should work with their clinicians to decide the best course of treatment for them based on what has and has not been proven to work.”

The authors, who were led by David Samson, MS, associate director of the AHRQ-supported Blue Cross and Blue Shield Association Evidence-based Practice Center in Chicago, reviewed findings from 53 randomized clinical trials of glucosamine, chrondroitin, and injections with hyaluronan preparations and 23 studies of arthroscopy. The review scrutinized individual studies concerned with these treatments’ effects, as well as meta-analyses that analyzed the combined evidence of groups of studies.

According to authors, better quality randomized clinical trials are needed to clarify whether these treatments are beneficial. However, given the aging of the population and increasing prevalence of obesity—both risk factors for osteoarthritis of the knee—”research on new approaches to prevention and treatment of osteoarthritis of the knee should be a high priority.”

A new survey released by the Council for Responsible Nutrition (CRN), Washington, D.C., shows that consumers’ use of dietary supplements has remained fairly consistent this year, with 68% of American adults saying they take dietary supplements compared to 66% last year. Interestingly, this year’s survey showed that more adults than last year consider themselves to be “regular” users of dietary supplement products, with 52% of Americans identifying themselves in that category, up from 46% in 2006.

The online survey, however, was inconsistent with the companion telephone survey conducted Ipsos-Public Affairs, which found that only 31% of Americans consider themselves “regular” users. Confidence levels for dietary supplements also differ between the phone and Internet respondents, with 80% of online participants saying that they are confident in the safety, quality and effectiveness of dietary supplements, compared to 67% of telephone respondents. Both numbers are consistent with discrepancies observed in last year’s results.

“This is the third year that we’ve conducted the survey online and it’s interesting to see the consistent trends building,” said Judy Blatman, vice president, Communications, CRN. “It’s intriguing that some of the results between Internet respondents and telephone respondents are so far apart. The psychographics of the online respondents may reflect that Internet users in general take a more active role in seeking out information about their healthcare, and consequently are more confident in the products they use. Because they tend to make more fully informed decisions about their health, it would make sense that the confidence numbers would be higher and would explain why they’re more conscientious about using supplements regularly.”

Despite the increased media coverage of various product safety issues over the past year, consumers’ trust in dietary supplement products does not appear to have been significantly impacted. Last year in the online survey 85% of consumers said that they believed that vitamin and mineral supplements are safe, compared to 84% this year; similarly, last year 70% agreed that herbal supplements are safe, compared to 70% this year.

However, Steve Mister, president and CEO, CRN, urged the industry not to get complacent when it comes to consumer trust. “We can’t take safety for granted. We need to make sure that there are quality control practices in place from start to finish, at each phase of the production process, to ensure the highest quality supplement products for our consumers. The publication of new good manufacturing practices for dietary supplements and the industry-wide Standardized Information on Dietary Ingredients (SIDI) voluntary program will help ensure quality, and the adverse event reporting law will also allow us to discover potential problematic patterns.”

Ms. Blatman also pointed out that healthcare professionals play an important role in instilling consumer trust, noting the online survey finding that demonstrated 68% of supplement users trust their doctor as a reliable source of information about supplements, with 40% also naming pharmacists.

As part of the “Life…supplemented” consumer wellness campaign, CRN recently announced that Ipsos is conducting a significant research study with 900 doctors and 300 nurses to learn more about their personal supplement use and whether or not that impacts the way they counsel their patients about dietary supplements. Results are expected to be released this month.