Quantifying the Race Stratified Impact of Socioeconomics on Graft Outcomes in Kidney Transplant Recipients.

BACKGROUND: Socioeconomic status (SES) is a significant determinant of health outcomes and may be an important component of the causal chain surrounding racial disparities in kidney transplantation. The social adaptability index (SAI) is a validated and quantifiable measure of SES, with a lack of studies analyzing this measure longitudinally or between races. METHODS: Longitudinal cohort study in adult kidney transplantation transplanted at a single-center between 2005 and 2012. The SAI score includes 5 domains (employment, education, marital status, substance abuse and income), each with a minimum of 0 and maximum of 3 for an aggregate of 0 to 15 (higher score → better SES). RESULTS: One thousand one hundred seventy-one patients were included; 624 (53%) were African American (AA) and 547 were non-AA. African Americans had significantly lower mean baseline SAI scores (AAs 6.5 vs non-AAs 7.8; P < 0.001). Cox regression analysis demonstrated that there was no association between baseline SAI and acute rejection in non-AAs (hazard ratio [HR], 0.92; 95% confidence interval [95% CI], 0.81-1.05), whereas it was a significant predictor of acute rejection in AAs (HR, 0.89; 95% CI, 0.80-0.99). Similarly, a 2-stage approach to joint modelling of time to graft loss and longitudinal SAI did not predict graft loss in non-AAs (HR, 1.01; 95% CI, 0.28-3.62), whereas it was a significant predictor of graft loss in AAs (HR, 0.23; 95% CI, 0.06-0.93). CONCLUSIONS: After controlling for confounders, SAI scores were associated with a lower risk of acute rejection and graft loss in AA kidney transplant recipients, whereas neither baseline nor follow-up SAI predicted outcomes in non-AA kidney transplant recipients.

African-American race modifies the influence of tacrolimus concentrations on acute rejection and toxicity in kidney transplant recipients.

STUDY OBJECTIVE: To determine the effect of tacrolimus trough concentrations on clinical outcomes in kidney transplantation, while assessing if African-American (AA) race modifies these associations. DESIGN: Retrospective longitudinal cohort study of solitary adult kidney transplants. SETTING: Large tertiary care transplant center. PATIENTS: Adult solitary kidney transplant recipients (n=1078) who were AA (n=567) or non-AA (n=511). EXPOSURE: Mean and regressed slope of tacrolimus trough concentrations. Subtherapeutic concentrations were lower than 8 ng/ml. MEASUREMENTS AND MAIN RESULTS: AA patients were 1.7 times less likely than non-AA patients to achieve therapeutic tacrolimus concentrations (8 ng/ml or higher) during the first year after kidney transplant (35% vs 21%, respectively, p<0.001). AAs not achieving therapeutic concentrations were 2.4 times more likely to have acute cellular rejection (ACR) as compared with AAs achieving therapeutic concentrations (20.8% vs 8.5%, respectively, p<0.01) and 2.5 times more likely to have antibody-mediated rejection (AMR; 8.9% vs 3.6%, respectively, p<0.01). Rates of ACR (8.3% vs 6.7%) and AMR (2.0% vs 0.9% p=0.131) were similar in non-AAs compared across tacrolimus concentration groups. Multivariate modeling confirmed these findings and demonstrated that AAs with low tacrolimus exposure experienced a mild protective effect for the development of interstitial fibrosis/tubular atrophy (IF/TA; hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.47-1.32) with the opposite demonstrated in non-AAs (HR 2.2, 95% CI 0.90-5.1). CONCLUSION: In contradistinction to non-AAs, AAs who achieve therapeutic tacrolimus concentrations have substantially lower acute rejection rates but are at risk of developing IF/TA. These findings may reflect modifiable time-dependent racial differences in the concentration-effect relationship of tacrolimus. Achievement of therapeutic tacrolimus trough concentrations, potentially through genotyping and more aggressive dosing and monitoring, is essential to minimize the risk of acute rejection in AA kidney transplant recipients.

Simulated estimates of pre-pregnancy and gestational diabetes mellitus in the US: 1980 to 2008.

PURPOSE: To simulate national estimates of prepregnancy and gestational diabetes mellitus (GDM) in non-Hispanic white (NHW) and non-Hispanic black (NHB) women. METHODS: Prepregnancy diabetes and GDM were estimated as a function of age, race/ethnicity, and body mass index (BMI) using South Carolina live singleton births from 2004-2008. Diabetes risk was applied to a simulated population. Age, natality and BMI were assigned to women according to race- and age-specific US Census, Natality and National Health and Nutrition Examination Surveys (NHANES) data, respectively. RESULTS: From 1980-2008, estimated GDM prevalence increased from 4.11% to 6.80% [2.68% (95% CI 2.58%-2.78%)] and from 3.96% to 6.43% [2.47% (95% CI 2.39%-2.55%)] in NHW and NHB women, respectively. In NHW women prepregnancy diabetes prevalence increased 0.90% (95% CI 0.85%-0.95%) from 0.95% in 1980 to 1.85% in 2008. In NHB women from 1980 through 2008 estimated prepregnancy diabetes prevalence increased 1.51% (95% CI 1.44%-1.57%), from 1.66% to 3.16%. CONCLUSIONS: Racial disparities in diabetes prevalence during pregnancy appear to stem from a higher prevalence of prepregnancy diabetes, but not GDM, in NHB than NHW.

Effectiveness of an intensive, school-based intervention for teen mothers.

PURPOSE: This study evaluated the effectiveness of a secondary teen pregnancy prevention intervention that includes school-based social work services coordinated with comprehensive health care for teen mothers and their children. METHODS: A prospective cohort study compared subsequent births to teen mothers followed for at least 24 months or until age 20 years (whichever was longer) compared with matched subjects from state data. Analyses were based on intent to treat and included chi(2), survival, and cost-benefit analysis. RESULTS: Subjects included 63 girls (97% eligible, 99% African-American, mean age 16 years). A propensity-matched comparison group (n = 252) did not differ from subjects. Participation in program components was good: (1) group meetings: 76%; (2) case management: 95%; (3) coordinated medical care: 63%. The majority of subjects used contraception (93%), with greater use of medroxyprogesterone associated with participation in coordinated medical care (80% vs. 50%, p = .0145). Subsequent births were more common in the comparison group (33%) than among subjects (17%) (p = .001), and survival curves were significantly different (p = .007) (hazard ratio = 2.5). There was a trend toward fewer births with increased participation in medical care (p = .08) and case management (p = .08) but not with group meetings. Cost savings were calculated as $19,097 per birth avoided or $5,055 per month. CONCLUSIONS: The intervention was effective in reducing subsequent births to teens; however selection bias of school enrollment cannot be excluded by this study. The cost savings of delayed births outweigh the expenses of this intensive model.