THU0199 A pilot study to assess the relationship between smoking and drug inefficacy in rheumatoid arthritis – part of a quality improvement project aimed at smoking cessation

Abstract

Background: It has long been known that patients with rheumatoid arthritis who smoke have more severe disease. This results in greater joint destruction and disability, and further increase in cardiovascular risk1. Patients' disease may be more difficult to control with disease modifying anti‐rheumatic drugs (DMARDs) and biologic drugs. Smoking may also interfere with the pharmacokinetics of biologic drugs2. Clinicians could then cycle through more of these expensive drugs because of inefficacy. As a modifiable risk factor smoking should be targeted to improve outcomes for patients. Objectives: To complete a pilot study examining for an association between smoking and drug inefficacy in rheumatoid arthritis. This baseline data was used in a quality improvement project aimed at reducing the prevalence of smoking in our rheumatology patients. Methods: We identified patients using a dataset and a database including all patients currently receiving biologics in Musgrave park hospital. Each patient had a diagnosis of rheumatoid arthritis and was being treated with a biologic. We randomly selected 100 patients with rheumatoid arthritis, 50 of whom were current smokers and 50 non‐smokers. We then performed a search on Northern Ireland's electronic care record for each patient and identified how many DMARDs and biologics were discontinued due to inefficacy. Inefficacy was defined as ongoing synovitis despite receiving the drug at adequate dosage for 3‐6 months resulting in the drug being discontinued. We also identified patients who received rituximab and the number of patients for which it was stopped due to inefficacy. Results: DMARDs and inefficacy: non‐smokers had on average 0.98 stopped and smokers had on average 2.2 stopped. Biologics and inefficacy: non‐smokers had on average 0.5 stopped and smokers had on average 0.82 stopped. Twenty smokers and twenty non‐smokers were treated with rituximab. Non‐smokers: 4 out of 20 had rituximab discontinued due to inefficacy. Smokers: 8 out of 20 had rituximab discontinued due to inefficacy. Conclusions: In this small sample of patients, we found that smokers had greater DMARD and biologic inefficacy, particularly with rituximab where smokers had double the rate of inefficacy compared to non‐smokers. Our quality improvement project aims to reduce the prevalence of smoking in our rheumatology patients which could result in better disease control, reduction in cardiovascular risk, and less drugs being cycled through. Aiming to achieve this, steps have been taken to set up a rheumatology smoking cessation clinic in our health trust.