Effect of education on racial disparities in access to kidney transplantation.

Higher education level might result in reduced disparities in access to renal transplantation. We analyzed two outcomes: (i) being placed on the waiting list or transplanted without listing and (ii) transplantation in patients who were placed on the waiting list. We identified 3224 adult patients with end-stage renal disease (ESRD) in United States Renal Data System with education information available (mean age of ESRD onset of 57.1 ± 16.2 yr old, 54.3% men, 64.2% white, and 50.4% diabetics). Compared to whites, fewer African Americans graduated from college (10% vs. 16.7%) and a higher percentage never graduated from the high school (38.6% vs. 30.8%). African American race was associated with reduced access to transplantation (hazard ratio [HR] 0.70, p < 0.001 for wait-listing/transplantation without listing; HR 0.58, p < 0.001 for transplantation after listing). African American patients were less likely to be wait-listed/transplanted in the three less-educated groups: HR 0.67 (p = 0.005) for those never completed high school, HR 0.76 (p = 0.02) for high school graduates, and HR 0.65 (p = 0.003) for those with partial college education. However, the difference lost statistical significance in those who completed college education (HR 0.75, p = 0.1). In conclusion, in comparing white and African American candidates, racial disparities in access to kidney transplantation do exist. However, they might be alleviated in highly educated individuals.

Education is associated with reduction in racial disparities in kidney transplant outcome.

In this study, we hypothesized that higher level of education might be associated with reduced racial disparities in renal transplantation outcomes. We used data from the United States Renal Data System (September 1, 1990-September 1, 2007) (n=79,223) and analyzed two outcomes, graft loss and recipient mortality, using Cox models. Compared with whites, African Americans had increased risk of graft failure (HR, 1.48; p<0.001) and recipient mortality (HR, 1.06; p=0.004). Compared with recipients who graduated from college, all other education groups had inferior graft survival. Specifically, compared with college-graduated individuals, African Americans who never finished high school had the highest risk of graft failure (HR, 1.45; p<0.001), followed by high school graduates (HR, 1.27; p<0.001) and those with some college education (HR, 1.18; p<0.001). A similar trend was observed in whites. In African Americans (compared with whites), the highest risk of graft failure was associated with individuals who did not complete high school (HR, 1.96; p<0.001) followed by high school graduates (HR, 1.47; p<0.001), individuals with some college education (HR, 1.45; p<0.001), and college graduates (HR, 1.39; p<0.001). A similar trend was observed with recipient mortality. In sum, higher education was associated with reduced racial disparities in graft and recipient survival.

Social Adaptability Index predicts access to kidney transplantation.

Identifying the group of subjects prone to disparities in access to kidney transplantation is important for developing potential interventions. Data from the United States Renal Data System (January 1, 1990-September 1, 2007; n = 3407) were used to study association between the Social Adaptability Index (SAI; based upon employment, marital status, education, income, and substance abuse) and outcomes (time to being placed on the waiting list and time to being transplanted once listed). Patients were 56.9 ± 16.1 yr old, 54.2% men, 64.2% white, and 50.4% had diabetes. SAI was higher in whites (7.4 ± 2.4) than African Americans (6.5 ± 2.6) [ANOVA, p < 0.001] and greater in men (7.4 ± 2.4) than in women (6.7 ± 2.5) [T-test, p < 0.001]. In multivariate model, greater SAI (range 0-12) was associated with increased likelihood of being placed on the waiting list (hazard ratio [HR] 1.19 [95% CI 1.15-1.23] per each point of increase in SAI, p < 0.001) and greater likelihood of receiving a transplant once listed (HR of 1.06 [95% CI 1.03-1.09] per point of increase in SAI, p < 0.001). Similar trends were observed in most of the subgroups (based upon race, sex, diabetic status, age, comorbidities, and donor type). SAI is associated with access to renal transplantation in patients with end-stage renal disease; it may be used to indentify individuals at risk of healthcare disparities.

Association between social adaptability index and survival of patients with chronic kidney disease.

BACKGROUND: While individual socioeconomic factors have been associated with clinical outcome, a composite index has not been developed. In this project, we tested the hypothesis that Social Adaptability Index (SAI) based on employment, education, income, marital status and substance abuse is associated with survival in chronic kidney disease (CKD) patients. METHODS: This is a retrospective cohort study of patients with CKD stage 2 or greater. We used the Third National Health and Nutrition Examination Survey (NHANES III) cohort data between 1988 and 1994 including those 18 years or older. Our primary variable of interest is SAI. Each component of SAI (employment status, education, marital status, and substance abuse) has been graded on the scale of 0-3, income has been graded on the scale 0-1. Age, sex, race, diabetes, co-morbidity index, body mass index (BMI), geographic location, haemoglobin, serum creatinine, serum albumin, serum cholesterol and Hba1c were used as covariates in multivariate analysis. The outcome of the study is patient's mortality. The time to death was calculated as time between the first interview by NHANES and death. RESULTS: We analysed 13 400 subjects with mean age of 50.6 ± 20-53.6% males, 44.4% white, 29.7% African American and 22.1% Mexican American-with 8.5% having diabetes, with an average number of co-morbid conditions of 2.7 ± 1.1. Lower SAI is associated with greater stage of CKD. Higher SAI was associated with decreased mortality [hazard ratio (HR) 0.88, P < 0.001, 95% confidence interval (CI) 0.86-0.89]. When SAI quintiles were analysed, we demonstrated a 'dose-dependent' association between SAI and survival. Subgroup analysis showed that this association of SAI and survival was present in all studied subgroups. The limitations of the study include retrospective design, potential misreporting and misclassification, and reverse causality. CONCLUSION: We demonstrated that SAI has a strong and clinically significant association with mortality in CKD patients.

The role of the economic environment in kidney transplant outcomes.

The relationship between global economic indicators and kidney allograft and patient survival is unknown. To investigate possible relationships between the two, we analyzed kidney transplant recipients receiving transplants between January of 1995 and December of 2002 (n = 105,181) in the USA using Cox regression models. We found that: The Dow Jones Industrial Average had a negative association with outcome at one year post-transplant (HR 1.03 and 1.06, p < 0.001 for graft and recipient survival, respectively) but changed to a protective effect in the late period (HR 0.77, p < 0.001, and HR 0.83, p < 0.001 for graft and recipient survival, respectively, five yr after transplantation). Unemployment rate had a protective effect at the time of transplantation (HR 0.97, p < 0.005) and at one year after transplantation (HR 0.95, p < 0.005) but changed to the opposite in the late period at the fifth post-transplant year (HR 1.35, p < 0.001, and HR 1.20, p < 0.001, for graft and recipient survival respectively). The Consumer Price Index measured at different post-transplant time points seems to have had a protective effect on the graft (HR 0.77, p < 0.001 at five yr) and recipient (HR 0.83, p < 0.001 at five yr) survival. Beyond three yr after transplantation, when some of the recipients lose Medicare benefits, economic downturns might have a negative association with the kidney graft and recipient survival.

Social adaptability index predicts overall mortality in patients with diabetes.

BACKGROUND: A quantifiable assessment of socioeconomic status and its bearing on clinical outcome in patients with diabetes is lacking. The social adaptability index (SAI) has previously been validated in the general population and in patients with chronic kidney disease, including those on dialysis and with kidney transplant. We hypothesize that SAI could be used in diabetes practice to identify a disadvantaged population at risk for inferior outcomes. METHODS: The NHANES-3 database of patients who have diabetes was analyzed. The association of the SAI (calculated as the linear combination of indicators of education status, employment, income, marital status, and substance abuse) with patient survival was evaluated using Cox model. RESULTS: The study population consisted of 1634 subjects with diabetes mellitus with mean age of 61.9±15.3 years; 40.9% males; 38.5% white, 27.7% African American, and 31.3% Mexican American. The highest SAI was in whites (6.9±2.5), followed by Mexican Americans (6.5±2.3), and then African Americans (6.1±2.6) (ANOVA, P<.001). SAI was higher in subjects living in metropolitan areas (6.8±2.6) compared to the rural population (6.3±2.4) (T test, P<.001). Also, SAI was greater in males (7.1±2.4) than in females (6.1±2.4) (T test, P<.001). SAI had significant association with survival (hazard ratio 0.9, P<.001) in the entire study population and in most of the subgroups (divided by race, sex, and urban/rural location). Furthermore, SAI divided into tertiles (≤5, 6 to 8, >8) demonstrated a significant and "dose-dependent" association with survival. CONCLUSION: Social adaptability index is associated with mortality in the diabetic population and is useful in identifying individuals who are at risk for inferior outcomes.

New social adaptability index predicts overall mortality.

INTRODUCTION: Definitions of underprivileged status based on race, gender and geographic location are neither sensitive nor specific; instead we proposed and validated a composite index of social adaptability (SAI). MATERIAL AND METHODS: Index of social adaptability was calculated based on employment, education, income, marital status, and substance abuse, each factor contributing from 0 to 3 points. Index of social adaptability was validated in NHANES-3 by association with all-cause and cause-specific mortality. RESULTS: Weighted analysis of 19,593 subjects demonstrated mean SAI of 8.29 (95% CI 8.17-8.40). Index of social adaptability was higher in Whites, followed by Mexican-Americans and then the African-American population (ANOVA, p < 0.001). The SAI was higher in subjects living in metropolitan compared to rural areas (T-test, p < 0.001), and was greater in men than in women (T-test, p < 0.001). In Cox models adjusted for age, comorbidity index, BMI, race, sex, geographic location, hemoglobin, serum creatinine, albumin, cholesterol, and glycated hemoglobin levels, SAI was inversely associated with mortality (HR 0.87 per point, 95% CI 0.84-0.90, p < 0.001). This association was confirmed in subgroups. CONCLUSIONS: We proposed and validated an indicator of social adaptability with a strong association with mortality, which can be used to identify underprivileged populations at risk of death.

The association between recipient alcohol dependency and long-term graft and recipient survival.

BACKGROUND: The causative role of alcohol consumption in renal disease is controversial, and its effect on renal graft and recipient survival has not been previously studied. METHODS: We analysed the association between pre-transplant [at the time of end-stage renal disease (ESRD) onset] alcohol dependency and renal graft and recipient survival. The United States Renal Data System (USRDS) records of kidney transplant recipients 18 years or older transplanted between 1 January 1995 and 31 December 2002 were examined. We used Kaplan-Meier analysis and Cox regression models adjusted for covariates to analyse the association between pre-transplant alcohol dependency and graft and recipient survival. RESULTS: In an entire study cohort of 60 523, we identified 425 patients with a history of alcohol dependency. Using Cox models, alcohol dependency was found to be associated with increased risk of death-censored graft failure [hazard ratio (HR) 1.38, P < 0.05] and increased risk of transplant recipient death (HR 1.56, P < 0.001). Subgroup analysis demonstrated an association of alcohol-dependency with recipient survival and death-censored graft survival in males (but not in females), and in both white and non-white racial subgroups. CONCLUSIONS: We concluded that alcohol dependency at the time of ESRD onset is a risk factor for renal graft failure and recipient death.