Facilitators to GBTT Prescribing
Several providers listed availability of the costly medication in the VHA as a facilitator to prescribing. Veterans can obtain GBTTs with little to no insurance cost or copayment, which is not always the case outside the VHA.
One recommendation for further facilitating prescribing of GBTTs involved eliminating the preauthorization requirement, particularly in first-line use for patients testing positive for ALK or EGFR mutations. Although the preauthorization was not seen as a significant barrier, removal of this formality could make prescribing easier.
Discussion
Although in some cases, testing weaknesses (lack of tissue, wait time to receive results) can interrupt a treatment trajectory, many of the barriers identified in this study are modifiable. Overwhelmingly, oncologists recommended making mutation testing reflexive for metastatic nonsquamous NSCLC. Implementing reflexive testing of patients, as recommended by guidelines, would understandably address issues related to variable utilization of genomic testing in VHA.12 Additionally, in response to system and facility barriers to mutation testing, other providers recommended standardizing the ordering procedure and location of results. Utilization of GBTT can be facilitated by eliminating the preauthorization requirement, particularly in first-line use for patients with positive mutations. Although the preauthorization was not seen as a significant barrier, removal of this formality could make prescribing easier.
This study extends previous research that identified underuse of genomic testing in community-based practices. The authors sought to interview a broad sample of providers from various facilities (small, large, CoC accredited, nonaccredited) to understand the range of conditions faced by VA providers. Some providers face more barriers than do others, whereas some face few or no barriers. This wide range of experiences can help to better understand the factors that facilitate guideline-adherent care.
Limitations
The authors recognize that availability of resources and testing and prescribing practices are constantly evolving and perhaps have improved since the data were collected. Thus, the age of the study data might be a limitation to the study. Like most qualitative studies, these findings are limited in their generalizability beyond the study population. Additionally, the authors were limited to recruiting oncologists with reliable contact information listed in the VHA directory. Although this could have introduced some degree of sampling bias, the authors are confident that the sample sufficiently represents the population of VHA-based medical oncologists who treat lung cancer. Despite these limitations, these findings provide novel perspectives on barriers and facilitators to genomic testing GBTT prescribing in the VHA. The authors identify modifiable barriers to testing and prescribing that can be addressed to improve and standardize care of advanced lung cancer in the VHA.
Conclusion
Efforts should be made to address modifiable barriers to mutation testing and guideline-consistent prescribing of GBTT in the VA setting. Implementation of specific practices like reflexive testing for all metastatic nonsquamous NSCLC, standardization of the mutation test ordering procedure, standardization of results reporting, and elimination of the preauthorization to prescribe GBTT could impact the utilization of GBTT in VHA.