“…The study cohort was defined using both demographics and clinical-related criteria from prior work involving readmission analysis in a pneumonia setting [6,25,26]. The study cohort included all adult patients (aged ≥ 18 years) who had an index (first) hospitalization from January 1, 2016, through November 31, 2016, with a principal inpatient diagnosis of pneumonia using the International Classification of Diseases, Tenth Revision, codes (J10.0, J10.1, J10.8, J11.0, J11.1, J11.8, J12.0, J12.1, J12.2, J12.3, J12.8, J12.9, J13, J14, J15.x, J16.0, J16.8, J17.0, J17.1, J17.2, J17.3, J17.8, J18.0, J18.1, J18.2, J18.8, J18.9, J69.0, B01.2, B20.6, B25.0, B59) [27,28] between January 1, 2016, and November 30, 2016.…”