Changes in coding of pneumonia and impact on the Hospital Readmission Reduction Program

Abstract

Objective: To evaluate whether changes in diagnosis assignment explain reductions in 30-day readmission for patients with pneumonia following the Hospital Readmission Reduction Program (HRRP). Data Sources: 100 percent MedPAR, 2008-2015. Study Design: Retrospective cohort study of Medicare discharges in HRRP-eligible hospitals. Outcomes were 30-day readmission rates for pneumonia under a “narrow” definition (used for the HRRP until October 2015; n = 2 288 644) and a “broad” definition that included certain diagnoses of sepsis and aspiration pneumonia (used since October 2015; n = 3 618 215). We estimated changes in 30-day readmissions in the pre-HRRP period (January 2008-March 2010), the HRRP implementation period (April 2010-September 2012), and the HRRP penalty period (October 2012-June 2015). Principal Findings: Under the narrow definition, adjusted annual readmission rates changed by +0.07 percentage points (pp) during the pre-HRRP period (95% CI: −0.03 pp, +0.18 pp), −1.07 pp during HRRP implementation (95% CI: −1.15 pp, −0.99 pp), and −0.09 pp during the penalty period (95% CI: −0.18 pp, −0.00 pp). Under the broad definition, 30-day readmissions changed by +0.21 pp during the pre-HRRP period (95% CI: +0.12 pp, +0.30 pp), −1.28 pp during HRRP implementation (95% CI: −1.35 pp, −1.21 pp), and −0.09 pp during the penalty period (95% CI: −0.16 pp, −0.02 pp). Conclusions: Changes in the coding of inpatient pneumonia admissions do not explain readmission reduction following the HRRP.