Variations in indicated care of patients with acute coronary syndromes in Queensland hospitals

Objective: To identify variation in the rates of use of key evidence-based therapies and in clinical outcomes among patients hospitalised with acute coronary syndromes (ACS). Design: Retrospective analysis of data on care processes and clinical outcomes of representative patient samples recorded by the Queensland Health Cardiac Collaborative registry. Setting: 18 public hospitals (3 tertiary, 15 non-tertiary) in Queensland, August 2001 to December 2003. Study population: 2156 patients who died or were discharged after troponin-positive ACS. Main outcome measures: Comparison of proportions of highly eligible patients receiving indicated care and in-hospital mortality between subgroups categorised by age, sex, comorbidities (diabetes, renal failure, chronic obstructive pulmonary disease and mental disorder), type of admitting hospital (tertiary or non-tertiary), and cardiologist involvement (transfer or non-transfer to cardiology unit). Results: Patients aged >= 65 years were less likely than younger patients to receive heparin (79% v 87%), beta-blockers (79% v 87%), lipid-lowering agents (78% v 87%), coronary angiography (51% v 66%), and referral to cardiac rehabilitation (17% v 33%). Patients with diabetes were less likely than others to receive coronary angiography (50% v 63%), while those with moderate to severe renal failure were less likely to receive thrombolysis (52% v 84%), heparin (71% v 83%), beta-blockers (69% v 84%), lipid-lowering agents (61% v 84%), in-hospital cardiac counselling (46% v 64%) and referral to cardiac rehabilitation (9% v 25%). Patients admitted to tertiary hospitals were more likely than those admitted to non-tertiary hospitals to receive coronary angiography (85% v 55%) and referral to cardiac rehabilitation (36% v 21%). Risk-adjusted mortality was highest in patients with moderate to severe renal failure (15% v 3%) and older patients (6% v 2%). Conclusions: Variations exist in the provision of indicated care to patients with ACS according to age, diabetic status, renal function and type of admitting hospital. Excess mortality in elderly patients and in those with advanced renal disease may be partially attributable to failure to use key therapies.