Comparative effect of inflation versus practice changes on the payments for care: an example from stroke

Abstract Background: Adjusting for inflation for longitudinal economics analyses is essential to account for changes in monetary valuation. Inflation calculators are common as they provide fast results with minimal resource expenditure. However, their sensitivity to new, high-cost interventions is unknown.Methods: We analyzed hospital payments for acute ischemic stroke survivors from the 2018 5% Medicare Limited Data Sets from the Centers for Medicare and Medicaid Services (CMS). Patients were stratified by severity using the Stroke Administrative Severity Index (SASI) score, which is a validated measure used to describe stroke severity at hospital discharge. Next, we inflated previously published 2014 payments using the US Consumer Price Index: Medical Care (CPI) rates from 2014 to 2018. Results: The inflated 2014 hospital care payments for Mild stroke survivors increased from $6,850 to $7,593, Moderate from $8,456 to $9,373 and Severe from $9,688 to $10,739. After comparing CPI inflated estimates from 2014 to 2018 we found that Mild and Moderate SASI levels were slightly less costly in the true 2018 payments than the inflated 2014 payments, while Severe SASI patients were $2,117 more costly than the 2014 adjusted costs. Our results indicate noteworthy differences in actual versus inflation-adjusted payments particularly for Severe stroke survivors. This is likely due to the emergence and integration of high-cost endovascular thrombectomies (eVT) into standard practice. Conclusions: Though inflation calculators are less resource intensive than cost analyses, they do not necessarily capture true cost changes for stroke survivors. This is one of many reasons that health economists should collaborate with clinicians to discuss clinical factors that may significantly influence longitudinal cost comparisons.