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Patient Migration

The Patient Migration report is part of the Analytic Team's 2020-2021 Research Plan to help support the Green Mountain Care Board. This report is based on the resident perspective, i.e. where the patient is going for care. The Analytic Team is also producing another, separate report covering the provider perspective, which describes where patients travel from for care. This second, separate report is the Patient Origin report.

An example of patient migration is: for residents of the Barre hospital service area, what can conclude about where they go for care? Does that change over time? To report on patient migration at the population level, we use the hospital service area of residence and primary insurance type as these have the greatest impact on migration. Other variables available for analysis are: patient age range, patient gender, claim count, and the average out of pocket costs. The summary file is created by aggregating total spend for every patient, month of eligibility, payer, HSA of residence, and HSA of care. Note, within this data structure, patients can live in more than one area in the year and month, and we also count visits to more than one HSA in the year and month. We allow these multiples over time because this most accurately represents the complete migration of populations. Also note, this report includes all provider types and all services within the HSA, not just those occurring at the hospitals.

The data are based on administrative claims for most of Vermont’s insured population (see VHCURES Overview for more information and limitations). Additional limitations specific to this report are listed here:


- Not all medical and pharmacy expenditures are captured on insurance claims. For example, capitated arrangements between insurers and providers, some case management payments, and pharmacy rebate payments are all examples of important areas of health care spending that are not included in claims.

- Fee-for-service (FFS) equivalent expenditures for Medicare beneficiaries attributed to an Accountable Care Organization (ACO) are included because they are the source used for determining the ultimate cost of care by Medicare.  Medicaid FFS equivalencies are excluded because the prospective payments are not reconciled to claims-level expenditures.  As a result, this analysis underestimates the total spending associated with Medicaid beneficiaries aligned to an ACO.

Claims Run Out

- This report uses VHCURES extract 250, with paid claims through 3/31/2020 for Commercial and Medicaid, and incurred claims through 12/31/2019 for Medicare. Although claims run out will affect the total spend for all insurance types, we expect Medicare expenditures to be more impacted due to the way the extract is received.


Patient Migration      (Interactive Report)

All Payer