SUBOPTIMAL ADHERENCE TO EVIDENCE BASED CORONARY ARTERY DISEASE (CAD) THERAPY: IMPACT OF GENDER, ETHNICITY, PRESCRIBING PHYSICIAN AND DRUG INTOLERANCE

BACKGROUND: Previous studies have examined the effect of a patient’s geographic place of residence on their access to cardiac care services, in particular as it applies to rates of procedure utilization and wait times. Less is known, however, about the effect of one’s geographic place of residence on clinical outcomes following these procedures. The purpose of this study was to examine 30-day rates of adverse events following cardiac surgery and to determine the effect of a patient’s geographic place of residence on these outcomes. METHODS: All patients undergoing non-emergent cardiac surgery at the sole, tertiary cardiac care center for the province of New Brunswick between April 2004 and March 2011 were identified. A patient’s geographic place of residence was defined as the driving distance from the patient’s home to the cardiac surgery center. Distance was divided into the following categories: 0-50km, 50-100km, 100-150km, 150-200km, 200-250km and >250km. Comparisons between distance categories were made on the basis of baseline clinical characteristics, intra-operative variables and rates of post-operative in-hospital and 30-day adverse events. Multivariable logistic regression was used to determine the risk-adjusted impact of increased distance on in-hospital and 30-day outcomes. The in-hospital adverse outcome of interest was a composite of reoperation, prolonged ventilation >24 hours, wound infection, stroke, renal failure, atrial fibrillation, and/or mortality, while the 30-day adverse outcome of interest was a composite of any complication (infectious, neurological, pulmonary, renal, valvular, vascular or other) and/or readmission from the time of discharge up until 30 days following surgery. RESULTS: 4493 patients were identified of whom 3897 (86.7%) had 30-day follow-up (0-50km: n1⁄4813; 50-100km: n1⁄4278; 100-150km: n1⁄41028; 150-200km: n1⁄4863; 200250km: n1⁄4405; and >250km: n1⁄41106). No differences were noted across distance categories in baseline clinical characteristics, intra-operative variables and rates of in-hospital adverse events. However, significant differences in 30-day rates of adverse events were noted (Table 1). Following risk adjustment, increased distance from the cardiac surgery center was independently associated with a greater likelihood of experiencing an adverse event at 30 days [0-50km: 1.00 (referent); 50-100km: OR 1.16 (95% CI 0.83-1.62); 100150km: 1.32 (1.05-1.65), 150-200km, 1.68 (1.33-2.11), 200-250km, 1.41 (1.06-1.88), and >250 km, 1.30 (1.041.63)]. CONCLUSION: Increased distance from the patient’s home to the cardiac surgery center was associated with worse 30-day outcomes following cardiac surgery. Further study is required to better understand why patients living farther are more likely to experience surgical complications and/or readmission to hospital during this study period.