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

2011

Racial Disparities in Medication Non-Adherence Among Veterans with Diabetes

Sample size: 11272 publication Evidence: high

Author Information

Author(s): Gebregziabher Mulugeta, Lynch Cheryl P, Mueller Martina, Gilbert Gregory E, Echols Carrae, Zhao Yumin, Egede Leonard E

Primary Institution: Center for Disease Prevention and Health Interventions for Diverse Populations, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, USA

Hypothesis

Quantile regression provides estimates of the effect of covariates on the conditional quantiles of medication possession ratio (MPR), leading to a more complete picture of differences between race/ethnicity groups.

Conclusion

Quantile regression is recommended for analyzing data that are heterogeneous, as it reveals differences in medication adherence that traditional methods may miss.

Supporting Evidence

Quantile regression showed that Non-Hispanic-Black (NHB) had statistically significantly lower MPR compared to Non-Hispanic-White (NHW) across all quantiles.
Other racial/ethnic groups had lower adherence than NHW only in the lowest quantile.
OLS and GLMM only showed differences in mean MPR between NHB and NHW, missing significant differences in the tails of the distribution.

Takeaway

This study looked at how different races stick to their diabetes medications. It found that Black veterans often take their medications less than White veterans.