Implementation of clinical pharmacogenetic testing in medically underserved patients: a narrative review.

As an emerging health technology, pharmacogenetic (PGx) testing has the capacity to improve medication therapy. However, implementation in medically underserved populations (MUPs) remains limited, which has the potential to increase healthcare disparities. While there is no single accepted definition for MUPs, demographic, socioeconomic, cultural, and geographic factors can lead to reduced access to healthcare, which contributes to disparate health outcomes in these populations. In the case of PGx testing, as MUPs have an increased risk of adverse drug events, have lower numbers of healthcare encounters, and are prescribed more medications which can be guided by PGx testing, additional benefits from PGx testing may occur in MUPs. Study of the acceptability and perceptions of PGx testing in MUPs, as reported in literature, provides support for the development of successful PGx testing implementations. Additionally, a few limited pilot PGx testing implementations in MUPs have assessed feasibility. However, further studies establishing the feasibility and effectiveness of PGx testing implementations in MUPs will enable more widespread PGx testing in those who are medically underserved. Thus, this narrative review explores the impact of medical underservice on health, PGx testing's potential impact on MUPs, and the research and early clinical implementations of PGx in MUPs.