Subjects and BAP-65 Classes

We have previously proposed the BAP-65 (elevated BUN, altered mental status, pulse > 109 beats/min, age > 65 years) system for application in AECOPD. This system is designed to only use information that is generally available to physicians at the time of patient presentation. BAP-65 assigns points based on BUN level, mental status, pulse, and age. In an earlier analysis of nearly 90,000 patients with AECOPD, we demonstrated that BAP-65 correlated with both the need for MV and in-hospital mortality.

In the present study we sought to validate the BAP-65 system in a separate and more recent cohort of patients with AECOPD. We also aimed to explore the usefulness of BAP-65 in a broader population to include AECOPD in patients suffering from acute respiratory failure at the time of presentation. Finally, we attempted to determine how the BAP-65 score correlated with measures of resource use, such as length of stay (LOS) and hospital costs.

Subjects and BAP-65 Classes

We included all people > 40 years of age (to minimize potential patients with asthma) in the analysis with either (1) a principal International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge code of COPD with acute exacerbation (491.21, 491.22, or 496.XX) or (2) a principal ICD-9-CM discharge code of acute respiratory failure (518.81) along with a secondary discharge code of COPD. We further restricted the eligible population to diagnosis-related groups (DRGs) (version 27) 190, 191, 192 (COPD), or DRG 189 (pulmonary edema or respiratory failure), or any of the four DRGs indicating that MV was performed in the index hospitalization (DRG 207, 208, 3, or 4). The analytic units were admissions.

The BAP-65 system is based on information available on initial hospital presentation. For patients who have none of the three main risk factors (BUN level > 25 mg/dL, altered mental status, or pulse > 109 beats/min), those < 65 years of age are designated as class I, whereas patients with no risk factors who are >65 years of age are classified as class II.