Schiff 2008.

Methods	ATTEST was a randomized, double‐blind, double‐dummy, placebo‐ and active (infliximab)‐controlled, 12‐month global trial
Participants	Abatacept, n = 156, infliximab, n = 165, placebo, n = 110. Eligible patients met the American College of Rheumatology (ACR) criteria for RA, were at least 18 years of age, had RA for at least 1 year and had an inadequate response to MTX. Abatacept group: Mean age (SD) = 49 yrs (12.5); gender = 83.3% female; disease duration (yrs) (SD) = 7.9 (8.5) Placebo group: Mean age (SD) = 49.4 yrs (11.5); gender = 87.3% female; disease duration (yrs) (SD) = 8.4 (8.6)
Interventions	Adult patients with active RA and an inadequate response to MTX were randomised by centre in a 3:3:2 ratio to 6 months of abatacept (approximating 10 mg/kg, n = 156), infliximab (3 mg/kg, n = 165), or placebo (n = 110) treatment by intravenous (IV) infusion, on a background of MTX
Outcomes	Primary outcome: DAS28 (ESR) Secondary: EULAR criteria were used to assess good responses ACR 20, 50 and 70 Physical function (HAQ‐DI) HRQoL(SF‐36) Adverse events
Notes	ATTEST: "Abatacept or infliximab vs placebo, a Trial for Tolerability, Efficacy and Safety in Treating rheumatoid arthritis’’ On day 198, placebo treated patients were reallocated to abatacept (with blinding maintained). Patients initially randomized to abatacept or infliximab continued their treatment.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Not stated in published article
Allocation concealment?	Unclear risk	Not stated in published article
Blinding? Patient assessed	Low risk	Additional info from BMS: "Subjects and clinical assessor(s) were blinded to treatment assignment". "In order to maintain the blind, study drug was administered intravenously (IV) on Days 1, 15, 29, 43, 57, 85, 113, 141, 169, 197, 225, 253, 281, 309, and 337 as described below. Because the dosing regimens for abatacept and infliximab were different, subjects received normal saline (NS) at some dosing visits to maintain the integrity of the blind."
Blinding? Physician assessed	Low risk	Additional info from BMS: "Subjects and clinical assessor(s) were blinded to treatment assignment".
Incomplete outcome data addressed? Efficacy outcomes	Low risk	94.2% in abatacept group and 97.3% in placebo group completed treatment at 6 months. Missing data were imputed using LOCF or non‐responders for ACR response. All withdrawals accounted for. "All patients who received at least one dose of study medication were assessed for efficacy and safety". Judged a low risk of bias given the > 80% completion rate in the treatment group.
Incomplete outcome data addressed? Safety outcomes	Low risk	94.2% in abatacept group and 97.3% in placebo group completed treatment at 6 months. All withdrawals accounted for. "All patients who received at least one dose of study medication were assessed for efficacy and safety". Judged a low risk of bias given the > 80% completion rate in the treatment group.
Free of selective reporting?	Low risk	"The primary endpoint was to evaluate a reduction in disease activity, measured by Disease Activity Score 28 (based on erythrocyte sedimentation rate levels; DAS28 (ESR)) with abatacept vs placebo at 6 months."
Free of other bias?	High risk	Funded by drug company. There is evidence that industry‐sponsored trials may overestimate the treatment effect (Bhandari 2004)