A Study to Determine the Risk of Cancer in Rheumatoid Arthritis (RA) Patients Who Use Abatacept and Other Biologic Agents

Inclusion Criteria: * RA patients will be identified using algorithms that require ≥ 1 rheumatologist (physician specialty code: 66) diagnosis codes for RA (at least one of the following ICD9 diagnosis codes: 714.0, 714.2, 714.81) at any time before the first claim for a specific drug (Index date) during the study period and ≥1 physician (affiliated with physician evaluation \& management codes, listed in the appendix 2) diagnosis codes within 12 months before the first claim for a specific drug use. The index date is defined as the date of the first claim for a specific drug use, and the baseline period is defined as 12 months prior to specific drug use * Naive users of biologics, including abatacept, anti-TNFs (i.e. etanercept, adalimumab, certolizumab, golimumab, infliximab), rituximab, and tocilizumab, will be defined specific to each drug as no claim for that therapy in any time prior to the index date * Eligible subjects, including cancer patients in SEER and non-cancer beneficiaries from 5% sample, must have been continuously enrolled in Medicare Parts A, B and D and not C at their index date and during baseline Exclusion Criteria: * Patients diagnosed with any cancer (ignoring non-melanoma skin cancer, which is not captured within SEER) before the use of biologics under study. Cancer cases will be identified based on the records in SEER * Patients who were younger than 18 years on the index date * Patients with claims for other types of auto-immune diseases (e.g. psoriatic arthritis, systemic lupus erythematosus) during baseline * Month or year of diagnosis of malignancy in SEER was unknown * Cancer cases who were identified by death certificate or autopsy only in SEER Other protocol defined inclusion/exclusion criteria could apply