Our search strategy yielded 268 suitable studies that met our selection criteria. These studies were published between 1979 and July 2004 -Week 2. (The references for these studies can be found at the LACDR Division of Pharmacology website [42] ). The total number of study subjects included in this review was 142,407. Of this group, 18% fell in Exacerbation Severity Level I, 78% in Level II, and 4% in Level III. When we re-analysed the data according to out-or in-patient settings, 18% were out-patients and 82% in-patients.