Our findings regarding overall LOS and cost are similar to a representative sample of US patients with COPD. This fact confirms the external validity of the BAP-65 in its application for outcome studies. The data concerning overall costs, furthermore, document the substantial economic burden of AECOPDs generally and provide more current information than prior analyses of the economics related to AECOPD hospitalization.

Our analysis has several significant limitations. We used administrative data to identify patients with AECOPD. Administrative data may not be accurate buy Cialis Online for this purpose, particularly as no objective criteria truly define an AECOPD. Coding bias, therefore, may have affected our findings. However, our approach to identifying those with AECOPD has been used in other analyses of AECOPD outcomes. We strived to improve our diagnostic precision by restricting the population to patients > 40 years of age. This should minimize classification bias by excluding patients potentially with asthma rather than COPD. Alternatively, using a database approach afforded the opportunity to validate BAP-65 in a very large population. Similarly, the retrospective nature of our study provides a limited substantiation of BAP-65.

Formal use in a prospective cohort for validation would be optimal. However, many currently used risk tools in pulmonary medicine, such as the Pulmonary Embolism Severity Index score, have only recently been prospectively evaluated despite their increasing clinical acceptance. We additionally lacked information on certain measures used to gauge the severity of chronic COPD, such as lung function. We expressly attempted to develop and validate a risk system that only required information that was routinely available to frontline clinicians. Spirometric data, for example, are not often available to the physician in the ED, and patients with AECOPDs may be too ill to perform spirometry.