The first broad long-term objective of the research is to demonstrate that an Emergency Diagnostic and Treatment Unit (EDTU) provides equal or improved quality of care and is a cost-effective alternative to hospital admission for two major conditions: the diagnosis of low-risk cardiac chest pain and the treatment of acute asthma The second long term objective is to promote the establishment and utilization of such units by disseminating the clinical, operational and cost-effectiveness findings to physicians and reimbursement agencies. Regarding the diagnosis of acute chest pain, the first specific aim is to evaluate low risk patients in the EDTU and classify them as positive or negative for acute myocardial infarction (AMI) and determine the proportion of negative AMI patients who can avoid hospitalization and be discharged home. The second specific aim is to validate these classifications via a two stage diagnostic cohort study. We will demonstrate that for such patients the quality of care is equal or improved compared to in-patient care. Regarding the treatment of acute asthma, the third specific aim utilizes a randomized controlled clinical trial for patients traditionally admitted. They are assigned to either an additional 8 hour period of intensive therapy in the EDTU or standard in-patient treatment. We classify each patient's treatment as success or failure; we recommend either discharge or admission. The fourth specific aim will demonstrate the efficacy and safety of this regimen by assessment of clinical outcomes and relapse rates. The fifth specific aim for both the diagnostic and treatment strategies is to conduct a rigorous cost-effectiveness analysis by comparing the cost per clinical outcome of randomized control and experimental arms during the initial hospital encounter and the 8 week follow-up period. The economic burden of in-patient care for chest pain and asthma exceeds $6 billion per annum; the demonstration of these clinical and economic aims will promote the development an alternative health care delivery method which would lead to substantial cost reductions.