Comparing jurisdiction-specific pharmaco-economic evaluations using medical purchasing power parities

To demonstrate how medical purchasing power parities (mPPP) may harmonize economic evaluations from different jurisdictions and enable comparisons across jurisdictions.

We describe the use of mPPPs and illustrate this with an example of economic evaluations of nab-paclitaxel with gemcitabine (Nab-P + Gem) versus gemcitabine monotherapy in the setting of metastatic pancreatic cancer. Following a literature search, we extracted data from cost-effectiveness studies on these treatments performed in various countries. mPPPs from the Organization for Economic Co-operation and Development were used to convert reported costs in the jurisdiction of origins to US dollars for the most current year using two possible pathways: (1) reported costs first adjusted by mPPP then adjusted by exchange index; and (2) reported costs first adjusted by exchange index then adjusted by mPPP.

Despite many of the pharmaco-economic evaluations sharing similar assumptions and inputs, even after mPPP conversion, residual heterogeneity was attributable to perspectives, discount rate, outcomes, and costs, among others; including in studies conducted in the same jurisdiction.

Despite the methodological challenges and heterogeneity within and across jurisdictions, we demonstrated that mPPP offers a way to compare economic evaluations across jurisdictions.