Using quantile regression to investigate racial disparities in medication non-adherence

<p>Abstract</p> <p>Background</p> <p>Many studies have investigated racial/ethnic disparities in medication non-adherence in patients with type 2 diabetes using common measures such as medication possession ratio (MPR) or gaps between refills. All these measures including MPR are quasi-continuous and bounded and their distribution is usually skewed. Analysis of such measures using traditional regression methods that model mean changes in the dependent variable may fail to provide a full picture about differential patterns in non-adherence between groups.</p> <p>Methods</p> <p>A retrospective cohort of 11,272 veterans with type 2 diabetes was assembled from Veterans Administration datasets from April 1996 to May 2006. The main outcome measure was MPR with quantile cutoffs Q1-Q4 taking values of 0.4, 0.6, 0.8 and 0.9. Quantile-regression (QReg) was used to model the association between MPR and race/ethnicity after adjusting for covariates. Comparison was made with commonly used ordinary-least-squares (OLS) and generalized linear mixed models (GLMM).</p> <p>Results</p> <p>Quantile-regression showed that Non-Hispanic-Black (NHB) had statistically significantly lower MPR compared to Non-Hispanic-White (NHW) holding all other variables constant across all quantiles with estimates and p-values given as -3.4% (p = 0.11), -5.4% (p = 0.01), -3.1% (p = 0.001), and -2.00% (p = 0.001) for Q1 to Q4, respectively. Other racial/ethnic groups had lower adherence than NHW only in the lowest quantile (Q1) of about -6.3% (p = 0.003). In contrast, OLS and GLMM only showed differences in mean MPR between NHB and NHW while the mean MPR difference between other racial groups and NHW was not significant.</p> <p>Conclusion</p> <p>Quantile regression is recommended for analysis of data that are heterogeneous such that the tails and the central location of the conditional distributions vary differently with the covariates. QReg provides a comprehensive view of the relationships between independent and dependent variables (i.e. not just centrally but also in the tails of the conditional distribution of the dependent variable). Indeed, without performing QReg at different quantiles, an investigator would have no way of assessing whether a difference in these relationships might exist.</p

The Effects of Financial Pressures on Adherence and Glucose Control Among Racial/Ethnically Diverse Patients with Diabetes

Abstract available at publisher's website

Nazism, Religion, and Human Experimentation

Multiple factors have been identified as contributing to the willingness of physicians and scientists to participate in the development and conduct of experiments carried out on Nazi concentration camp prisoners, including the economic challenges then facing physicians, the potential for increased status and power in the Nazi government, and their own hostility toward Jews and others deemed “not worth living.” They conducted these experiments against a backdrop of their societies’ longstanding anti-Semitic sentiments, the promulgation of anti-Jewish rhetoric by Christian authorities, and the incorporation into law of increasingly severe and restrictive anti-Jewish measures and, ultimately, embraced efforts to eradicate all Jews and evidence of Jewishness. This chapter argues that religion was relevant not only to the question of who was targeted by Nazi medical policy—Jews, conceived of by the Nazis as a race rather than a religion—but also to the question of who was doing the targeting—physicians who appear to have identified religiously primarily as Christians and who interpreted Nazi dogma as congruent with their religious beliefs and teachings.https://doi.org/10.1007/978-3-030-44150-0_