Multiyear Rehospitalization Rates and Hospital Outcomes in an Integrated Health Care System

This cohort study examines rehospitalization factors, hospitalization and mortality, discharge disposition, and the changes in these variables over time among all adult patients in the Kaiser Permanente Northern California health system.

g Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.

F OOTNOTES
a Rates employ hospitalization episodes (which can include linked stays for patients who were transported) as the denominator. Numbers in parentheses always refer to the range across the 21 study hospitals. The period preceding the penalty phase of the Hospital Readmissions Reductions Program (HRRP), which took effect on 10/1/12, is divided into two epochs, with the first of these constituting the reference period for multivariate analyses and other comparisons. The period after the penalty phase also is divided into two epochs, with the first of these (through the end of 2014) matching that of the study of Gupta et al. and the second the remaining years.
b Hospital episodes where patients transitioned from OBS to INP status are classified as INP.
c Refers to patients whose linked hospitalization episode began at a hospital not owned by Kaiser Foundation Hospitals, Inc. These hospitalizations, involving 1,800 patients, had elevated inpatient (3.5%) and 30-day (11.1%) mortality, compared to 3.2% and 9.9% in the rest of the KPNC CHF cohort. Since we lacked information on their initial illness severity (the most important component of our mortality risk adjustment model) they are not included in inpatient and 30-day mortality analyses but are included in rehospitalization analyses, where admission illness severity plays a smaller role. See Escobar et al., 2008Escobar et al., , 2013Escobar et al., and 2015  g Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.

FOOTNOTES
a Rates employ hospitalization episodes (which can include linked stays for patients who were transported) as the denominator. Numbers in parentheses always refer to the range across the 21 study hospitals. The period preceding the penalty phase of the Hospital Readmissions Reductions Program (HRRP), which took effect on 10/1/12, is divided into two epochs, with the first of these constituting the reference period for multivariate analyses and other comparisons. The period after the penalty phase also is divided into two epochs, with the first of these (through the end of 2014) matching that of the study of Gupta et al. and the second the remaining years.
b Hospital episodes where patients transitioned from OBS to INP status are classified as INP.
g Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.

FOOTNOTES
a Rates employ hospitalization episodes (which can include linked stays for patients who were transported) as the denominator. Numbers in parentheses always refer to the range across the 21 study hospitals. The period preceding the penalty phase of the Hospital Readmissions Reductions Program (HRRP), which took effect on 10/1/12, is divided into two epochs, with the first of these constituting the reference period for multivariate analyses and other comparisons. The period after the penalty phase also is divided into two epochs, with the first of these (through the end of 2014) matching that of the study of Gupta et al. and the second the remaining years. g Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.

FOOTNOTES
a Rates employ hospitalization episodes (which can include linked stays for patients who were transported) as the denominator. Numbers in parentheses always refer to the range across the 21 study hospitals. The period preceding the penalty phase of the Hospital Readmissions Reductions Program (HRRP), which took effect on 10/1/12, is divided into two epochs, with the first of these constituting the reference period for multivariate analyses and other comparisons. The period after the penalty phase also is divided into two epochs, with the first of these (through the end of 2014) matching that of the study of Gupta et al. and the second the remaining years.
b Refers to patients whose linked hospitalization episode began at a hospital not owned by Kaiser Foundation Hospitals, Inc. These hospitalizations, involving 46,072 patients, had elevated inpatient (5.6%) and 30-day (10.3%) mortality, compared to 3.1% and 6.5% in the rest of the KPNC INP cohort. Since we lacked information on their initial illness severity (the most important component of our mortality risk adjustment model) they are not included in inpatient and 30-day mortality analyses but are included in rehospitalization analyses, where admission illness severity plays a smaller role. Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.

FOOTNOTES
a Rates employ hospitalization episodes (which can include linked stays for patients who were transported) as the denominator. Numbers in parentheses always refer to the range across the 21 study hospitals. The period preceding the penalty phase of the Hospital Readmissions Reductions Program (HRRP), which took effect on 10/1/12, is divided into two epochs, with the first of these constituting the reference period for multivariate analyses and other comparisons. The period after the penalty phase also is divided into two epochs, with the first of these (through the end of 2014) matching that of the study of Gupta et al. and the second the remaining years.
b Refers to patients whose linked hospitalization episode began at a hospital not owned by Kaiser Foundation Hospitals, Inc. These hospitalizations, involving 8,448 patients, had elevated inpatient (1.2%) and 30-day (4.2%) mortality, compared to 1.0% and 3.8% in the rest of the KPNC OBS cohort. Since we lacked information on their initial illness severity (the most important component of our mortality risk adjustment model) they are not included in inpatient and 30-day mortality analyses but are included in rehospitalization analyses, where admission illness severity plays a smaller role. See Escobar et al., 2008Escobar et al., , 2013Escobar et al., and 2015 c The HEDIS membership definition restricts the denominator to patients with continuous health plan membership in the 12 months preceding and the 30 days following hospital discharge, with a maximum gap in coverage of 45 days in the preceding 12 months. The public reporting definition only includes patients meeting HEDIS membership criteria and excludes OBS hospitalizations and INP hospitalizations with length of stay < 24 hours.
d Charlson score was calculated using the methodology of Deyo et al. (1992).
g Transports-in (footnote b) are excluded from inpatient and 30-day mortality. Only patients who survived to discharge are included in the post-discharge outcomes. Non-elective rehospitalizations are those that began in the ED, were for an ambulatory care sensitive condition, and/or had a LAPS2 ≥ 60, as described in Escobar et al. (2015). Composite outcome = non-elective rehospitalization or death within 30 days after discharge. Regular SNF (%) 3.5 (1.9 -6.7) 3.9 (2.1 -7.1) 3.6 (2.1 -7.1) 3.2 (1.6 -6.3) 3.5 (1.9 -6. c Refers to patients whose linked hospitalization episode began at a hospital not owned by Kaiser Foundation Hospitals, Inc. These hospitalizations, involving 23,051 patients, had elevated inpatient (2.5%) and 30-day (3.5%) mortality, compared to 1.4% and 2.5% in the rest of the KPNC under 65 cohort. Since we lacked information on their initial illness severity (the most important component of our mortality risk adjustment model) they are not included in inpatient and 30-day mortality analyses but are included in rehospitalization analyses, where admission illness severity plays a smaller role. See Escobar et al., 2008Escobar et al., , 2013Escobar et al., and 2015 The HEDIS membership definition restricts the denominator to patients with continuous health plan membership in the 12 months preceding and the 30 days following hospital discharge, with a maximum gap in coverage of 45 days in the preceding 12 months. The public reporting definition only includes patients meeting HEDIS membership criteria and excludes OBS hospitalizations and INP hospitalizations with length of stay < 24 hours. e Charlson score was calculated using the methodology of Deyo et al. (1992). f The COmorbidity Point Score, version 2 (COPS2) is assigned based on all diagnoses incurred by a patient in the 12 months preceding the index hospitalization. The univariate relationship of COPS2 with 30-day mortality is as follows: 0-39, 1.7%; 40-64, 5.2%; 65+, 9.0%. The Laboratory-based Acute Physiology Score, version 2 (LAPS2) is assigned based on a patient's worst vital signs, pulse oximetry, neurological status, and 16 laboratory test results in the preceding 24 (discharge LAPS2) or 72 hours (admission LAPS2). The univariate relationship of an admission LAPS2 with 30-day mortality is as follows: 0-59, 1.0%; 60-109, 5.0%; 110+, 13.7%; for LAPS2dc, the relationship is 0-59, 2.2%; 60-109, 8.1%; 110+, 20.5%.
g Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.
h Transports-in (footnote c) are excluded from inpatient and 30-day mortality. Only patients who survived to discharge are included in the post-discharge outcomes. Non-elective rehospitalizations are those that began in the ED, were for an ambulatory care sensitive condition, and/or had a LAPS2 ≥ 60, as described in Escobar et al. (2015). Composite outcome = non-elective rehospitalization or death within 30 days after discharge. g Refers to disposition among patients discharged alive from the hospital. SNF = skilled nursing facility. Note that hospice referral is independent of discharge disposition.
h Transports-in (footnote c) are excluded from inpatient and 30-day mortality. Only patients who survived to discharge are included in the post-discharge outcomes. Non-elective rehospitalizations are those that began in the ED, were for an ambulatory care sensitive condition, and/or had a LAPS2 ≥ 60, as described in Escobar et al. (2015). Composite outcome = non-elective rehospitalization or death within 30 days after discharge.