Risk adjusting community-acquired pneumonia hospital outcomes using automated databases

To describe the development and assessment of the Abbreviated Fine Severity Score (AFSS), a simplified version of the Pneumonia Severity Index (PSI) suitable for providing risk-adjusted reports to clinicians caring for patients hospitalized with community-acquired pneumonia.

Retrospective cohort study.

We defined the AFSS based on data available in administrative and laboratory databases. We downloaded and linked these hospitalization and laboratory data from 2 cohorts (11,030 patients and 6147 patients) hospitalized with community-acquired pneumonia in all Kaiser Permanente Medical Care Program hospitals in northern California. We then assessed the relationship between the AFSS and mortality, length of stay, intensive care unit admission, and the use of assisted ventilation. Using logistic regression analysis, we assessed the performance of the AFSS and determined the area under the receiver operating characteristic curve (c statistic). Using a combination of manual and electronic medical record review, we compared the AFSS with the full PSI in 2 subsets of patients in northern California and Denver, Colorado, whose medical records were manually reviewed.

The AFSS compares favorably with the PSI with respect to predicting mortality. It has good discrimination with respect to inhospital (c = 0.74) and 30-day (c = 0.75) mortality. It also correlates strongly with the PSI (r = 0.87 and r = 0.93 in the 2 medical record review subsets).

The AFSS can be used to provide clinically relevant risk-adjusted outcomes reports to clinicians in an integrated healthcare delivery system. It is possible to apply risk-adjustment methods from research settings to operational ones.