Service Outcomes for Germline Test Delivery for Patients With Metastatic Prostate Cancer.

Importance: Germline testing can improve cancer management through use of targeted treatment and risk-specific cancer screening and prevention. Objective: To compare service outcomes (care that is safe, timely, effective, efficient, equitable, and patient-centered) for germline testing under delivery models with varying involvement of oncologists and genetics clinicians. Design, Setting, and Participants: This quality improvement study was performed within the Veterans Health Administration (VHA) from May 3, 2021, to May 2, 2023, with follow-up through November 2, 2023 using mixed methods analysis. Participants included patients with metastatic prostate cancer (mPRCA), germline test orders, and cancer care visits. Key informants included patients, clinicians, and VHA laboratory personnel. Exposures: Germline testing delivery models within the VHA: traditional (ie, genetic consultation), full mainstream (oncologists perform all activities), partial mainstream (oncologist perform some pretest activities and then refer to genetics clinicians), and embedded (genetics clinicians working within oncology clinics). Main Outcomes and Measures: Key informant interviews identified barriers and facilitators of germline testing delivery that were mapped to implementation strategies and service outcomes. Multivariable logistic regression estimated associations among patient characteristics, delivery models, effectiveness (only 1 cancer care visit before the test order), efficiency (no incomplete orders), and timeliness (<7 days from cancer care visit to order). Results: The study population included 1964 patients with mPRCA with a mean (SD) age of 72.5 (8.1) years. Implementation strategies of quality monitoring, networking, adaptability, and involving patients addressed most barriers and facilitators. Compared with the traditional model, the embedded model was associated with greater effectiveness (odds ratio [OR], 2.11; 95% CI, 1.34-3.33), efficiency (OR, 7.37; 95% CI, 3.06-22.00), and timeliness (OR, 6.65; 95% CI, 4.40-10.16), although impractical due to limited genetics clinician availability. The full mainstream model was associated with greater efficiency (OR, 2.12; 95% CI, 1.35-3.30) and timeliness (OR, 12.33; 95% CI, 8.90-17.29), although complex and difficult to establish. The partial mainstream model was associated with less efficiency (OR, 0.51; 95% CI, 0.34-0.75) with fragmented care and the highest frequency of incomplete orders, particularly among non-Hispanic Black patients. Conclusions and Relevance: In this quality improvement study of patients with mPRCA, the embedded and full mainstream germline testing delivery models offered advantages over the traditional approach. Currently, the full mainstream model may be most practical to ensure timely germline testing. If the VHA's genetic workforce expands, then the embedded model should be considered. These findings may be helpful to health care organizations planning germline testing implementation.