{'fraction_non_alphanumeric': 0.033687294031490296, 'fraction_numerical': 0.012449652142072502, 'mean_word_length': 5.139325842696629, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The efficacy of glucosamine sulfate in osteoarthritis: financial and nonfinancial conflict of interest.

Glucosamine has attracted a lot of interest as a specific drug for osteoarthritis (OA). Pharmacologic treatment of the disease is in fact dominated by the use of nonspecific analgesics or antiinflammatory agents, including nonsteroidal antiinflammatory drugs (NSAIDs) that have shown modest, although sound, symptomatic efficacy over short-term treatment courses, but no relevant effect during long-term use (1) and a poor risk/benefit ratio (2). Conversely, glucosamine appears to be safe (3). In addition, well-conducted clinical research with a particular form of glucosamine sulfate has shown clinically relevant symptom modification over medium-term treatment of knee OA (4). This symptom modification is sustained for years, and there is an intriguing suggestion of possible disease (structure) modification (5,6). These long-term effects are particularly relevant (7), given the chronic and progressive nature of this degenerative joint disease. Several reviews and meta-analyses have scrutinized the efficacy of glucosamine. At least 3 of these have emerged as being worthy of attention: a most important Cochrane Review first released in 2001 and updated in 2005 (8), a meta-analysis from our group that had the merit of being the first to include the long-term trials of glucosamine sulfate (9), and finally, 2 meta-analyses from a group in Boston. The Boston group’s first meta-analysis was published in 2000 (10), but its usefulness is limited because it was performed before all of the most relevant trials with glucosamine. Vlad and coworkers have now updated their meta-analysis, and it is published in this issue of Arthritis & Rheumatism (11). All these meta-analyses suggest the efficacy of at least 1 particular formulation of glucosamine sulfate, which is a prescription drug in Europe. Actually, the recent European League Against Rheumatism practice guidelines for knee OA assign to glucosamine sulfate the highest level of evidence, 1A, and strength of the recommendation, A, acknowledging the high quality of the studies performed (12). In contrast, Vlad and coworkers dismiss the quality of the most important glucosamine sulfate trials, as well as the major differences in glucosamine forms, products, dosages, and trial designs, and support only a view of bias due to industry involvement (11), a conclusion I find to be inaccurate and misleading. There are therefore 2 aspects of this issue that deserve attention. The first is of course the actual role of industry bias in clinical research, and the second is an understanding of why the findings of the meta-analysis by Vlad et al are of concern.