A national assessment of legacy versus new generation Medicaid data

Health Serv Res. 2022 Aug;57(4):944-956. doi: 10.1111/1475-6773.13937. Epub 2022 Feb 21.


Objective: To compare the performance of Medicaid legacy, Medicaid new generation, and Medicare claims on data analytic tasks.

Data sources: Medicaid Analytic eXtract (MAX) claims (legacy) of 100% beneficiaries in 2011 (all states except Idaho), 2012 (all states), 2013 (28 states), and 2014 (17 states); 2016 Transformed Medicaid Statistical Information System Analytic Files (TAF) claims (new generation) of 100% beneficiaries from all states; Medicare claims of 20% beneficiaries in 2011-2014, 2016.

Study design: We focused on the chain of events that starts with an out-of-hospital medical emergency and ends with hospital death or survival to discharge. We developed six data quality indicators to assess ambulance variables; linkage between claims; external cause of injury code reporting; and death reporting on hospital discharge status codes. For the latter, we estimated injury severity and modeled its association with death in the Medicare population. We used the model to compare reported versus expected deaths by injury severity in the Medicaid population. Datasets were compared by state and fee-for-service versus managed care.

Data extraction methods: Medicare and Medicaid beneficiaries with emergency ambulance transports.

Principal findings: Medicare claims had high performance across indicators and states; MAX claims substantially underperformed on multiple indicators in most states. For example, most states reported external cause codes for over 90% of Medicare but less than 15% of Medicaid injury cases. Medicaid fee-for-service did not consistently perform better than Medicaid managed care. Compared with MAX, TAF claims performed significantly better on some indicators but continued to have poor external cause code reporting. Finally, MAX and TAF managed care records reported deaths at discharge in the range of expected deaths; however, fee-for-service claims might have underreported high-severity injury deaths.

Conclusions: New generation Medicaid claims performed better than legacy claims on some indicators, but much more improvement is needed to allow high-quality policy analysis.

Keywords: Medicaid; Medicare; data quality; death reporting; injuries; medical emergencies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Fee-for-Service Plans
  • Humans
  • Managed Care Programs
  • Medicaid*
  • Medicare*
  • Patient Discharge
  • United States