OBJECTIVES To evaluate the clinical effectiveness of biologic therapies in the treatment of rheumatoid arthritis (RA) as measured by change in disease severity. METHODS Patient self-reported data were collected from the 2008 Rheumatoid Arthritis Patient Study. Patients with RA were asked to rate their current disease severity (mild, moderate or severe), as well as severity at the time of diagnosis and before treatment. Comparisons were made between respondents who received biologic therapies (abatacept, adalimumab, etanercept, infliximab, or rituximab) versus those treated with non-biologic treatments. An improvement in severity is defined as less severe (changes from severe/moderate to moderate/mild) after the current treatment. RESULTS Of 2048 respondents to the survey, the mean age was 51.9, and 74.3% were female. The average duration from RA diagnosis was 11.9 years. For patients treated with biologic therapies, the average duration of the treatment was 3.7 years. There were no statistical significant differences in age, gender and duration from RA diagnosis between patients who were treated with a biologic therapy versus those who were not. At baseline more patients reported their disease status as severe (47.2%) in the biologic group, compared to patients in the non-biologic group (21.3%). Only 9.7% of patients in the biologic group versus 29.5% of patients in the non-biologic group reported their disease status as mild. However, 44.6% of patients in the biologic group versus 25.9% of the non-biologic group reported an improvement in severity after the current treatment, while 11.6% of patients in the biologic group versus 15.3% of the non-biologic group reported increased severity in disease state (chi square P<0.001) after the current treatment. CONCLUSIONS In the real world setting, RA patients treated with biologic therapies self-reported more severe disease than patients treated with non-biologic therapies. Biologic therapies significantly reduced patient-reported RA disease severity, compared to non-biologic therapies.