• Costs, outcomes and estimation of the cost-effectiveness of abciximab in the prevention of ischemic events over six months of follow-up

      Reed, Shelby Ogilvie; Mullins, C. Daniel (1998)
      Abciximab is an antiplatelet inhibitor used in conjunction with percutaneous revascularization procedures to decrease the risk of ischemic complications such as death, nonfatal MI or subsequent revascularization procedures like angioplasty or CABG. Although the efficacy of abciximab is rarely disputed based on evidence from three large clinical trials, the cost-effectiveness of the drug when used during routine practice has been questioned since it costs approximately $1,350 per patient treated. This study was undertaken to estimate the effectiveness of abciximab in patients treated at University of Maryland Medical System (UMMS) and to estimate the incremental cost-effectiveness ratio (ICER) defined as the cost per event avoided. The composite endpoint consisted of death, MI or subsequent revascularization procedure over 6-months of follow-up. Proportional hazards regression revealed that abciximab was associated with a lower risk of ischemic events among patients with more severe angiographic morphology. Patients who received a shortened infusion of the drug (<10 hours) were at a greater risk of experiencing an event than those who received an infusion for 10-14 hours. Also, patients who underwent coronary stenting were less likely to have an event while patients with multivessel disease or a history of a percutaneous revascularization procedure were at a higher risk of experiencing an event. The cost-effectiveness analysis was performed for a subgroup of patients with more severe coronary morphology using a matched cohort design. The point estimate of the ICER revealed that it cost about $20,680 to prevent an ischemic event over six months in high-risk patients treated with abciximab. Confidence intervals for the ICER were computed using Taylor series approximation, Fieller's theorem and bootstrapping, and were graphically represented with ellipses of equal probability. Overall, the data were consistent with a wide range of plausible estimates due to a relatively small denominator in the ICER.