Cause for concern in the use of non-steroidal anti-inflammatory medications in the community -a population-based study

Background: Non-steroidal anti-inflammatory (NSAID) medications are a common cause of reported adverse drug side-effects. This study describes the prevalence of non-steroidal anti-inflammatory (NSAID) use (other than low-dose aspirin) and the presence of co-existing relative contraindications to NSAID use and chronic conditions in a representative population sample. Methods: Data were analysed from 3,206 adults attending first follow-up of the North West Adelaide Health Study (NWAHS) in 2004 - 2006, a longitudinal representative population study. Medications were brought into study clinic visits by participants. Clinical assessment included measured blood pressure, kidney function, serum cholesterol, blood glucose. Questionnaires assessed demographics, lifestyle risk factors, physician-diagnosed chronic conditions. Data were weighted to census measures by region, age group, gender, and probability of selection in the household, to provide population representative estimates. Pearson's Chi-square tests determined significant differences in proportions. Multiple logistic regression was used to examine associations of socio-demographic characteristics with use of NSAIDs. Results: Of 3,175 participants, 357 (11.2%), and 16% of those aged > 55 years, reported using either non-specific NSAIDs or COX-2 inhibitors, other than low-dose aspirin. Among people using NSAIDs, 60.8% had hypertension, 30.8% had Stage 3 or higher chronic kidney disease, 17.2% had a history of cardiovascular disease (CVD) and 20.7% had a > 15% 10-year CVD risk. The prevalence of NSAID use among people with hypertension was 16%, with kidney disease 15.9%, and a history of CVD 20.0%. Among people taking diuretics, 24.1% were also taking NSAIDs, and of those taking medications for gastro-esophageal reflux, 24.7% were on NSAIDs. Prescription-only COX-2 inhibitors, but not other NSAIDs, were used more by people > 75 years than by 35-54 year olds (OR 3.7, 95% CI 2.0, 6.7), and also were more commonly used by people with hypertension, cardiac and kidney disease. Conclusions: There is a high prevalence of current NSAID use among groups at-risk for significant drug-related adverse events or who have major chronic conditions that are relative contraindications to NSAID use. Assessment of absolute risks regarding cardiovascular and kidney disease need to take into account use of medications such as NSAIDs. The potential to make a substantial impact on chronic disease burden via improved use of NSAIDs is considerable.