Reports on Massachusetts Acute Hospital Case Mix Database

Massachusetts Acute Care Hospital Inpatient Discharge Data (FFY 2016-2019)
Publication Materials

CHIA has launched a new report series providing analyses and trends sourced from the Massachusetts Acute Hospital Case Mix Database. The first report, published in December 2020, offers new insights into hospital inpatient utilization patterns in the period leading up to the outbreak of COVID-19. Massachusetts Acute Care Hospital Inpatient Discharge Data (FFY 2016-2019) presents key measures of inpatient utilization overall and by hospital, patient, and discharge characteristics.

This report establishes an important baseline of inpatient utilization that can be used for public health initiatives, analyses of preventable hospitalizations and readmissions, and comparative cost and outcomes research. To better understand the vital role of inpatient services in the continuum of health care services in the Commonwealth, CHIA has analyzed inpatient stays in Massachusetts acute care hospitals over a four-year period, from Federal Fiscal Year (FFY) 2016 to FFY 2019.

Under state law, CHIA maintains a database of stay-level encounters with acute care hospitals going back more than 20 years. Collectively known as Case Mix, the databases capture each inpatient admission, emergency department visit, and outpatient observation stay at an acute care hospitals in Massachusetts. Case Mix captures the medical reason for the visit, procedures and services provided, charges incurred, and duration of the visit, as well as patient demographics.

For further information about the Massachusetts Acute Hospital Case Mix Database (Case Mix), including information about data governance, data submissions, data enhancements, and use cases, please see the Overview of the Massachusetts Acute Hospital Case Mix Database (December 2019).

In addition to this report, CHIA is developing parallel reports for emergency department encounters and the outpatient observation stays to be published in 2021.

 Key Findings:

  • From FFY 2016 to 2019, overall acute care discharge volume remained relatively stable, while total patient days of care increased each year, reflecting a longer average length of stay for inpatient hospitalizations.

  • Nearly half of all hospitalizations had Medicare as the expected primary payer; slightly less than one-third had commercial as their expected primary payer, and around one in five inpatient discharges had Medicaid as the expected primary payer.

  • One in six inpatient discharges (17.5% in FFY 2019) required intensive care.

  • The most common primary diagnoses for hospital admissions other than childbirth and other maternal-related care were septicemia, heart failure, hip and knee replacements, and pneumonia.

  • There was increase in the severity of illness classification between 2016 and 2019.



FY19 Case Mix Standard Reporting Inpatient Overview 

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