OBJECTIVES:

Adjusting cost of resources used for inflation in economics analyses is essential to account for changes in monetary value. Use of inflation factors are common as they provide fast results with minimal resource expenditure. However, their sensitivity to new, high-cost interventions is rarely examined. Our objective was to compare inflation-adjusted cost weights to empirically derived costs over a four-year time span using acute ischemic stroke (AIS) as an example.

METHODS:

First, we estimated initial hospital payments for AIS patients using the 2018 5% Medicare Limited Data Sets (LDS) 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 from administrative data. Next, we inflated previously published 2014 payments using the Medical Care Consumer Price Index change from 2014 to 2018.

RESULTS:

The initial hospital payments for Mild stroke increased from $6,850 to $7,593, Moderate from $8,456 to $9,373 and Severe from $9,688 to $10,739. Mild and Moderate SASI levels were slightly less costly in the observed 2018 payments than the inflated 2014 payments, while severe stroke patients were $2,117 more costly than the 2014 inflation-adjusted costs. Our results indicate substantial differences in observed versus inflation-adjusted payments particularly for Severe stroke survivors. This is likely due to the increased use of tissue plasminogen activator (tPA) combined with endovascular thrombectomy and the integration of these high-cost procedures into standard practice.

CONCLUSIONS:

Though inflation calculators are less resource intensive than cost analyses, they do not necessarily capture cost changes in clinical practice patterns. This is one of many reasons that health economists should team with clinicians to discuss clinical factors that may significantly influence longitudinal cost comparisons.