This study utilized aggregated laboratory data from Exact Sciences Laboratories LLC (ESL), the exclusive national laboratory for mt-sDNA testing, on a patient navigation program conducted at the SMC.

This retrospective analysis included Spanish-speaking individuals aged 45 to 75 years old from the SMC who received an mt-sDNA test kit from ESL between October 1, 2021, and August 1, 2022. The individuals were categorized into two groups—Spanish-language outreach (SLO) or English-language outreach (ELO)—based on the language of patient navigation outreach they received after kit shipment. The program was split into 2 phases—the initial outreach phase and the extended outreach phase. During the initial 45 days, the SLO group received outreach in Spanish, and the ELO group received outreach in English. Subsequently, both groups received extended English-language outreach from day 46 until day 365. During the initial 45 days, robust navigation support was provided to individuals in both groups, involving frequent interactions via emails, texts, and/or calls. During the extended English-language outreach period (day 46 onwards), the frequency of these interactions gradually decreased. It is important to note that while the outreach differed by language (Spanish vs. English) during the initial 45-day period, the content, frequency, and format of all messages were standardized between groups. The only tailored component was the use of language-concordant outreach, without additional cultural or content modifications.

The analysis included variables such as patient demographics (age, sex), provider specialty (e.g., primary care provider [PCP] and nurse practitioner/physician assistant [NP/PA]), social vulnerability index (SVI), median household income based on residential ZIP code, and outreach type (SLO or ELO).

The analysis excluded individuals aged below 45 years, those with less than 365 days since the mt-sDNA test kit shipment date, and those who participated in ESL’s clinical studies (to minimize selection bias toward potentially more adherent patients). These data were de-identified and compliant with the Health Insurance Portability and Accountability Act (HIPAA); the current study was exempt from Institutional Review Board (IRB) review.

Descriptive statistics were used to summarize patient characteristics and 365-day adherence rates. The primary outcome was mt-sDNA test adherence, defined as the percentage of kits returned with completed tests and successful results within 365 days of the initial shipment date. Cumulative adherence over time was assessed and visualized using line plots with 95% confidence intervals at regular time intervals. Between-group differences in adherence were evaluated using χ2 or Fisher’s exact tests, as appropriate. Multivariable logistic regression was performed to identify factors independently associated with adherence, including patient navigation outreach language, age, sex, provider specialty, social vulnerability index quartile, and ZIP code–level median household income. All tests were 2-sided, with P < 0.05 considered statistically significant.