Racial disparities in diabetes care among incident breast, prostate, and colorectal cancer survivors: a SEER Medicare study.

Background: Many cancer survivors with co-morbid diabetes receive less diabetes management than their non-cancer counterparts. We sought to determine if racial/ethnic disparities exist in recommended diabetes care within 12 months of an incident breast, prostate, or colorectal cancer diagnosis. Because co-morbid diabetes decreases long-term survival, identifying predictors of guideline-concordant diabetes care is important.

Methods: Using the Surveillance, Epidemiology, and End Results cancer registry linked to Medicare claims, we included beneficiaries aged 67+ years with diabetes and incident, non-metastatic breast, prostate, or colorectal cancer between 2008 and 2013. Primary outcomes were diabetes care services 12 months after diagnosis: (1) HbA1c test, (2) eye exam, and (3) low-density lipoprotein (LDL) test. Using modified Poisson models with robust standard errors, we examined each outcome separately.

Results: We included 34,643 Medicare beneficiaries with both diabetes and cancer. Mean age at diagnosis was 76.1 (SD 6.2), 47.2% were women; 35% had breast, 24% colorectal, and 41% prostate cancer. In the 12 months after incident cancer diagnosis, 82.4% received an HbA1c test, 55.3% received an eye exam, 77.8% had an LDL test, and 42.0% received all three tests. Compared to non-Hispanic Whites, Blacks were 3% (95% CI 0.95-0.98) less likely to receive a HbA1c test, 10% (95% CI 0.89-0.92) less likely to receive a LDL test, and 8% (95% 0.89-0.95) less likely to receive an exam eye. Blacks and Hispanics were 16% (95% CI 0.81-0.88) and 7% (0.88-0.98) less likely to receive all three tests, after accounting for confounders. Racial/ethnic differences persisted across cancer types.

Conclusion: Blacks and Hispanics with breast, prostate, and colorectal cancer and diabetes received less diabetes care after cancer diagnosis compared to non-Hispanic Whites. Differences were not explained by socio-economic factors or clinical need.

Implications For Cancer Survivors: Our findings are concerning given the high prevalence of diabetes and poor cancer outcomes among racial/ethnic minorities. The next step in this line of inquiry is to determine why minorities are less likely to receive comprehensive diabetes care in order to develop targeted strategies to increase receipt of appropriate diabetes management for these vulnerable populations.