How do people with knee osteoarthritis use osteoarthritis pain medications and does this change over time? Data from the Osteoarthritis Initiative

• Published in: Arthritis research & therapy 2013-09, Vol.15 (5), p.R106-R106, Article R106
• Main Authors: Kingsbury, Sarah R, Hensor, Elizabeth M A, Walsh, Ceara A E, Hochberg, Marc C, Conaghan, Philip G
• Format: Article
• Language: English
• Subjects: Acetaminophen - administration & dosage; Acetaminophen - therapeutic use; Aged; Analgesics; Analgesics - administration & dosage; Analgesics - therapeutic use; Anti-Inflammatory Agents, Non-Steroidal - administration & dosage; Anti-Inflammatory Agents, Non-Steroidal - therapeutic use; Antiarthritic agents; Arthralgia - drug therapy; Body Mass Index; Care and treatment; Cross-Sectional Studies; Databases, Factual - statistics & numerical data; Dietary Supplements; Drug therapy; Drug Therapy, Combination; Female; Follow-Up Studies; Health aspects; Humans; Knee Joint - drug effects; Knee Joint - physiopathology; Logistic Models; Male; Methods; Middle Aged; National Institutes of Health (U.S.); Opioids; Osteoarthritis; Osteoarthritis, Knee - drug therapy; Osteoarthritis, Knee - epidemiology; Osteoarthritis, Knee - physiopathology; Pain; Pharmaceutical industry; Retrospective Studies; Surveys and Questionnaires; Time Factors; United States - epidemiology
• ISSN: 1478-6354; 1478-6362; 1478-6354
• DOI: 10.1186/ar4286

The aim of this analysis was to describe comprehensively the cross-sectional and longitudinal patterns of analgesic and nutraceutical medication use for knee osteoarthritis (OA) in a contemporary US cohort and to investigate associated demographic and clinical factors. Baseline, 12, 24 and 36 month data were obtained retrospectively from the National Institutes of Health Osteoarthritis Initiative. Participants had symptomatic radiographic knee OA. Multiple binary logistic regression models identified characteristics independently associated with the use of analgesics or nutraceuticals. We included 987 subjects (55.9% female, mean age 61.5 years, 71.0% white). At baseline, 68.2% reported frequent use of a conventional analgesic or nutraceutical for joint pain (for more than half of the previous month). Non-prescription non-steroidal anti-inflammatory drugs (NSAIDs) were the most frequently reported medications (26.8%), even in those more than 75-years old. Multiple conventional analgesics were used by 11.9%. Frequent analgesic use was more likely in women (odds ratio (OR) 1.8 (95% confidence interval (CI) 1.3 to 2.3)) and people with more pain (moderate 1.7 (1.2 to 2.4); severe 3.1 (2.1 to 4.7)); nutraceutical use was less likely in non-whites (0.4 (0.3 to 0.6)), those more than 74-years old (0.6 (0.3 to 0.9)) and those with comorbidities (0.6 (0.5 to 0.9)) and more likely in people with Kellgren-Lawrence (KL) grade 4 (2.2 (1.5 to 3.3)). Overall there was no change in the proportion of participants frequently using prescription or over the counter (OTC) analgesics at 36 months, although most people had changed medication type; of those using a traditional analgesic at baseline approximately one third were still using the same type at 36 months (ranging from 26.2% of baseline prescription NSAID users to 40.6% of baseline acetaminophen users). All participants reporting baseline analgesic use also reported 36 month analgesic use. Female participants (OR 95% CI 1.2 to 3.2, P = 0.009), those with high body mass index (1.2 to 4.8, P = 0.010) and those with moderate (1.6 to 2.6, P = 0.090) or severe (1.8 to 12.0, P = 0.002) baseline pain were more likely to use pain medication during the 36 month follow-up period; participants more than 75-years old were less likely (0.2 to 1.0, P = 0.053). Most people with knee OA used pharmacological therapies frequently, and use appeared to be according to American College of Rheumatology recommendations. Change in medication