Equitable Implementation of Mailed Stool Test-Based Colorectal Cancer Screening and Patient Navigation in a Safety Net Health System.

BACKGROUND: Mailed stool testing programs increase colorectal cancer (CRC) screening in diverse settings, but whether uptake differs by key demographic characteristics is not well-studied and has health equity implications. OBJECTIVE: To examine the uptake and equity of the first cycle of a mailed stool test program implemented over a 3-year period in a Central Texas Federally Qualified Health Center (FQHC) system. DESIGN: Retrospective cohort study within a single-arm intervention. PARTICIPANTS: Patients in an FQHC aged 50-75 at average CRC risk identified through electronic health records (EHR) as not being up to date with screening. INTERVENTIONS: Mailed outreach in English/Spanish included an introductory letter, free-of-charge fecal immunochemical test (FIT), and lab requisition with postage-paid mailer, simple instructions, and a medical records update postcard. Patients were asked to complete the FIT or postcard reporting recent screening. One text and one letter reminded non-responders. A bilingual patient navigator guided those with positive FIT toward colonoscopy. MAIN MEASURES: Proportions of patients completing mailed FIT in response to initial cycle of outreach and proportion of those with positive FIT completing colonoscopy; comparison of whether proportions varied by demographics and insurance status obtained from the EHR. KEY RESULTS: Over 3 years, 33,606 patients received an initial cycle of outreach. Overall, 19.9% (n = 6672) completed at least one mailed FIT, 5.6% (n = 374) tested positive during that initial cycle, and 72.5% (n = 271 of 374) of those with positive FIT completed a colonoscopy. Hispanic/Latinx, Spanish-speaking, and uninsured patients were more likely to complete mailed FIT compared with white, English-speaking, and commercially insured patients. Spanish-speaking patients were more likely to complete colonoscopy after positive FIT compared with English-speaking patients. CONCLUSIONS: Mailed FIT outreach with patient navigation implemented in an FQHC system was effective in equitably reaching patients not up to date for CRC screening.

Spatial Insights for Understanding Colorectal Cancer Screening in Disproportionately Affected Populations, Central Texas, 2019.

INTRODUCTION: Colorectal cancer (CRC) screening can reduce morbidity and mortality; however, important disparities exist in CRC uptake. Our study examines the associations of distance to care and frequency of using primary care and screening. METHODS: To examine the distribution of screening geographically and according to several demographic features, we used individual patient-level data, dated September 30, 2018, from a large urban safety-net health system in Central Texas. We used spatial cluster analysis and logistic regression adjusted for age, race, sex, socioeconomic status, and health insurance status. RESULTS: We obtained screening status data for 13,079 age-eligible patients from the health system's electronic medical records. Of those eligible, 55.1% were female, and 55.9% identified as Hispanic. Mean age was 58.1 years. Patients residing more than 20 miles from one of the system's primary care clinics was associated with lower screening rates (odds ratio [OR], 0.63; 95% CI, 0.43-0.93). Patients with higher screening rates included those who had a greater number of primary care-related (nonspecialty) visits within 1 year (OR, 6.90; 95% CI, 6.04-7.88) and those who were part of the county-level medical assistance program (OR, 1.61; 95% CI, 1.40-1.84). Spatial analysis identified an area where the level of CRC screening was particularly low. CONCLUSION: Distance to primary care and use of primary care were associated with screening. Priorities in targeted interventions should include identifying and inviting patients with limited care engagements.

Complex roles of hybrid lipids in the composition, order, and size of lipid membrane domains.

Hybrid lipids (HL) are phospholipids with one saturated chain and one unsaturated chain. HL are hypothesized to act as linactants (i.e., 2D surfactants) in cell membranes, reducing line tension and creating nanoscopic lipid domains. Here we compare three hybrid lipids of different chain unsaturation (16:0-18:1PC (POPC), 16:0-18:2PC (PLPC), and 16:0-20:4PC (PAPC)) in their abilities to alter the composition, line tension, order, and compactness of lipid domains. We found that the liquid-ordered (Lo) and liquid-disordered (Ld) lipid domains in PAPC/di18:0PC(DSPC)/cholesterol and PLPC/DSPC/cholesterol mixtures are micrometer-sized, and only the POPC/DSPC/cholesterol system has nanoscopic domains. The results indicate that some HLs with polyunsaturated chains are not linactants, and the monounsaturated POPC displays both properties of weak linactants and "Ld-phase" lipids such as di18:1PC (DOPC). The obtained phase boundaries from giant unilamellar vesicles (GUV) show that both POPC and PLPC partition well in the Lo phases. Our MD simulations reveal that these hybrid lipids decrease the order and compactness of Lo domains. Thus, hybrid lipids distinguish themselves from other lipid groups in this combined "partitioning and loosening" ability, which could explain why the Lo domains of GUVs, which often do not contain HL, are more compact than the raft domains in cell membranes. Our line tension measurement and Monte Carlo simulation both show that even the monounsaturated POPC is a weak linactant with only modest ability to occupy domain boundaries and reduce line tension. A more important property of HLs is that they can reduce physical property differences of Lo and Ld bulk domains, which also reduces line tension at domain boundaries.

Preparation of giant unilamellar vesicles from damp lipid film for better lipid compositional uniformity.

Giant unilamellar vesicles (GUVs) containing cholesterol often have a wide distribution in lipid composition. In this study, GUVs of 1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC)/1,2-distearoyl-sn-glycero-3-phosphocholine(DSPC)/cholesterol and 1,2-diphytanoyl-sn-glycero-3-phosphocholine(diPhyPC)/1,2-dipalmitoyl-sn-glycero-3-phosphocholine(DPPC)/cholesterol were prepared from dry lipid films using the standard electroformation method as well as a modified method from damp lipid films, which are made from compositional uniform liposomes prepared using the Rapid Solvent Exchange (RSE) method. We quantified the lipid compositional distributions of GUV by measuring the miscibility transition temperature of GUVs using fluorescence microscopy, since a narrower distribution in the transition temperature should correspond to a more uniform distribution in GUV lipid composition. Cholesterol molecules can demix from other lipids in dry state and form cholesterol crystals. Using optical microscopy, micron-sized crystals were observed in some dry lipid films. Thus, a major cause of GUV lipid compositional heterogeneity is the demixing of lipids in the dry film state. By avoiding the dry film state, GUVs prepared from damp lipid films have a better uniformity in lipid composition, and the standard deviations of miscibility transition temperature are about 2.5 times smaller than that of GUVs prepared from dry lipid films. Comparing the two ternary systems, diPhyPC/DPPC/cholesterol GUVs has a larger cholesterol compositional heterogeneity, which directly correlates with the low maximum solubility of cholesterol in diPhyPC lipid bilayers (40.2±0.5mol%) measured by light scattering. Our data indicate that cholesterol interacts far less favorably with diPhyPC than it does with other PCs. The damp lipid film method also has a potential of preparing GUVs from cell membranes containing native proteins without going through a dry state.