OBJECTIVES:  In patients with rheumatoid arthritis (RA) receiving the anti-TNF therapy adalimumab, circulating drug levels are associated with treatment response. Commercial tests (using a method called ELISA) can monitor anti-TNF drug levels in routine practice but the accuracy of this approach is uncertain. This study aimed to synthesise all published evidence on the accuracy of adalimumab drug level measurement by ELISA to detect treatment response in RA. METHODS:  A systematic review identified all published receiver operating characteristic (ROC) curve analyses that measured adalimumab drug levels by ELISA tests to detect treatment response in RA. Medline and Embase were searched electronically (from inception to August 2016). Two researchers identified studies using pre-defined inclusion criteria. Test outcomes were classified as positive if drug levels exceeded the study-specific cut-point. Data on study design characteristics, sample characteristics, and test outcomes from 2x2 tables (true-positive; false-positive; true-negative; false-negative) were extracted. QUADAS-2 was used to assess study quality. A hierarchical bivariate meta-analysis synthesised findings to account for between-study heterogeneity and correlation between sensitivity and specificity. RESULTS: