Explaining persistent under-use of colonoscopic cancer screening in African Americans: A systematic review

IntroductionAlthough African Americans have the highest incidence and mortality from colorectal cancer (CRC), they are less likely than other racial groups to undergo CRC screening. Previous research has identified barriers to CRC screening among African Americans. However we lack a systematic review that synthesizes contributing factors and informs interventions to address persistent disparities.MethodsWe conducted a systematic review to evaluate barriers to colonoscopic CRC screening in African Americans. We developed a conceptual model to summarize the patient-, provider-, and system-level barriers and suggest strategies to address these barriers.ResultsNineteen studies met inclusion criteria. Patient barriers to colonoscopy included fear, poor knowledge of CRC risk, and low perceived benefit of colonoscopy. Provider-level factors included failure to recommend screening and knowledge deficits about guidelines and barriers to screening. System barriers included financial obstacles, lack of insurance and access to care, and intermittent primary care visits.ConclusionsThere are modifiable barriers to colonoscopic CRC screening among African Americans. Future interventions should confront patient fear, patient and physician knowledge about barriers, and access to healthcare services. As the Affordable Care Act aims to improve uptake of preventive services, focused interventions to increase CRC screening in African Americans are essential and timely

Density of bounded maps in Sobolev spaces into complete manifolds

International audienceGiven a complete noncompact Riemannian manifold $N^n$, we investigate whether the set of bounded Sobolev maps $(W^{1, p} \cap L^\infty) (Q^m; N^n)$ on the cube $Q^m$ is strongly dense in the Sobolev space $W^{1, p} (Q^m; N^n)$ for $1 \le p \le m$. The density always holds when $p$ is not an integer. When $p$ is an integer, the density can fail, and we prove that a quantitative trimming property is equivalent with the density. This new condition is ensured for example by a uniform Lipschitz geometry of $N^n$. As a byproduct, we give necessary and sufficient conditions for the strong density of the set of smooth maps $C^\infty (\overline{Q^m}; N^n)$ in $W^{1, p} (Q^m; N^n)$