Request Case Mix Data
Get step-by-step instructions and support informative to apply for a Case Mix data extract.
Submit Case Mix Data
Get resources, requirements and instructions to submit data on inpatient discharges, emergency department visits, and outpatient observation stays.
Annual Release Process
CHIA’s Case Mix annual releases include one year’s worth of hospital data submissions.
Data Intake and Internal Processing
CHIA works with approximately 70 Massachusetts hospitals throughout the year to ensure valid, high quality quarterly data submissions. Hospitals are required to deliver their submission files within 75 days after the end of each quarter. CHIA runs each file through a series of file- and field-level edits to confirm formatting and to check for data quality issues. CHIA has a strict limit on errors, expecting the files to be 99% error-free. CHIA notifies providers if their file(s) do not pass these intake edits and requires resubmissions.
Release Creation
To prepare each annual release, CHIA compiles the 4 quarters of data submissions and completes a 4-week quality assurance validation process with the providers to test the completeness and quality of select fields. If data submission fixes are required, hospitals spend time fixing, validating, and resubmitting data files. Following receipt of all files, CHIA loads the data into the Case Mix Data Warehouse and performs a series of steps including data cleaning and creation of derived fields. Release creation can take 8 to 12 weeks depending on whether we identify issues during testing.
Data Quality and Release Assurance Testing
CHIA’s quality assurance team performs an 8- to 10-week quality assurance validation process to test the completeness and quality of select fields as well as any new product features and enhancements. If updates are required as a result of testing, CHIA performs comprehensive regression testing. After completing quality assurance testing, CHIA’s release assurance team validates the data creation process and ensures data completeness and accuracy. We then extract the most recent data to create the annual Case Mix Release Data Mart, which becomes the source for all data extracts.
Delivery of Data Extracts
CHIA extracts data from the Case Mix Release Data Mart to create extract files for its customers. It can take 5 to 7 days to create an extract file. CHIA prioritizes delivery of extracts to Commonwealth agencies doing research in support of healthcare policy. Second priority is given to organizations that submit data. Third priority goes to independent researchers.
Case Mix Documentation Archive
Recommended Links
CHIA Regulations (CMR)
Access CHIA's regulations governing health care data collection and reporting in Massachusetts, including current rules, administrative bulletins, and hearings.
Resultant Research Using CHIA Data
Browse published research studies that used the Massachusetts All Payer Claims Database or CHIA's case mix data, organized by topic and publication date.
Health Care Settings & Providers
Analysis and reports on health care clinicians and the places care services are delivered, including hospital profiles, nursing facilities, primary care, behavioral health services, and Case Mix reporting.