Cost-effectiveness of primary care-based risk assessment and hereditary cancer genetic testing.

BACKGROUND: Guidelines recommend identifying individuals with a family or personal history of cancer, offering genetic testing, with the goal of managing disease risk. Yet, risk assessment ("screening") and genetic testing remain underutilized in the primary care setting and the value of an optimal strategy for engaging individuals is unknown. Our goal is to estimate the incremental cost, incremental effectiveness, and incremental cost-effectiveness ratio (ICER) between two population-based engagement strategies in proportions of individuals risk assessed and tested, by providing these services in a primary care setting. METHODS: Data were obtained from the EDGE (Early Detection of GEnetic risk)-clinic- randomized controlled trial that evaluated two engagement strategies - an in-clinic point of care (POC) strategy and a direct participant engagement (DPE) strategy that involved (e)mailing invitations after a visit. At risk participants were offered complementary genetic testing and counseling. Using these data, we constructed a decision-analytic cohort model and compared the POC to DPE strategy. We modeled testing all clinic participants over a two-year timeframe and present results from both health-system and limited societal perspectives. Outcomes were the proportion of participants risk-assessed and tested, the costs for each strategy, and the ICERs. RESULTS: From the health-system perspective, costs for approaching 100,000 participants were $641,278 (POC) and $702,653 (DPE). The POC strategy led to 14,490 (46%) of participants completing risk assessment and the DPE strategy to 6,385 (7%) participants, thus POC dominated DPE for risk assessment completion (68% of simulations). The POC strategy led to fewer individuals completing testing than the DPE strategy [780 (73%) vs. 1,184 (77%)], revealing an ICER of $152 (health-system) and $136 (limited societal) perspectives in favor of DPE (52% and 58% of simulations). With substantial uncertainty, results suggest that the DPE strategy may provide good value for money spent on testing at a willingness-to-pay test-kit cost of $250. CONCLUSIONS AND RELEVANCE: That the incremental cost-effectiveness of risk assessment versus testing contrasts, suggests that engagement approaches play an important role in shaping outcomes of population-based risk assessments. A hybrid approach (DPE, followed by POC for those who do not respond) may be optimally cost-effective. TRIAL REGISTRATION: NCT04746794; Date: February 4, 2021.