Prescribing patterns of glucosamine in an older population: a national cohort study

BACKGROUND: Glucosamine is commonly prescribed as a disease modulating agent in osteoarthritis. However, the evidence to date suggests that it has a limited impact on the clinical symptoms of the disease including joint pain, radiological progression, function and quality of life. The aim of this study was to examine the prescribing patterns of glucosamine from 2002–2011 in an elderly Irish national population cohort using data from the Health Service Executive Primary Care Reimbursement (HSE-PCRS) General medical services (GMS) Scheme. METHODS: Patients aged ≥ 70 years on the HSE-PCRS pharmacy claims database between January 2002 and December 2011 were included. ATC code M01AX05 (glucosamine) was extracted. Prevalence rates per 1000 eligible population with 95% confidence intervals were calculated for all years and age groups (70–74 years, ≥75 years). A negative binomial regression analysis was used to determine longitudinal usage trends and compare prevalence rates across years, sex and age groups. RESULTS: The annual patient rate of glucosamine prescribing increased significantly from 13.0/1000 eligible population (95% CI 12.6-13.4) in 2002 to 68.7/1000 population (95% CI 67.8-69.5) in 2009 before decreasing to 62.4/1000 population (95% CI 61.6-63.2) in 2011. The rate of prescribing of glucosamine varied with sex, with women receiving significantly more prescriptions than men. The cost of glucosamine also increased from 2002–2008. In 2008 total expenditure reached a high of €4.6 million before decreasing to €2.6 million in 2011. CONCLUSION: The national trend in prescribing of glucosamine increased significantly from 2002 to 2009 before decreasing in 2010 and 2011, in keeping with current international guidelines. There is a need for awareness among healthcare professionals and patients alike of the best available evidence to inform decision making relating to the prescription and consumption of such supplements.