Social Adaptability Index predicts access to kidney transplantation

The association of socioeconomic status on kidney transplant access and outcomes: a nationwide cohort study in Taiwan

BACKGROUND

Conflicting evidence exists regarding the relationship between socioeconomic status and access to or outcomes after kidney transplantation. This study analyzed the effects of individual and neighborhood socioeconomic status on kidney transplant access and outcomes in Taiwan.

METHODS

We used a retrospective cohort study design and performed comparisons using the Cox proportional hazards model after adjusting for risk factors. Data were collected from the National Health Insurance Bureau of Taiwan data (2003-2012).

RESULTS

Patients with high individual and neighborhood socioeconomic status had higher chances of receiving kidney transplants than those with low individual and neighborhood socioeconomic status [adjusted hazard ratio (aHR) = 2.04; 95% CI: (1.81-2.31), p < 0.001]. However, there were no significant differences in post-transplant graft failure or patient mortality in Taiwan between individuals of varying socioeconomic status after five years. When we stratified kidney transplants by domestic and overseas transplantation, there were no significant differences in post-transplant mortality and graft failure, but individuals who received a kidney graft in Taiwan with high individual and neighborhood socioeconomic status experienced lower risks of graft failure (aHR = 0.55; [95% CI 0.33-0.89], p = 0.017).

CONCLUSION

A relevant disparity exists in accessing kidney transplantation in Taiwan, depending on individual and neighborhood socioeconomic status. However, results post transplantation were not different after five years. Improved access to waitlisting, education, and welfare support may reduce disparities.

A scoping review of inequities in access to organ transplant in the United States

Background

Organ transplant is the preferred treatment for end-stage organ disease, yet the majority of patients with end-stage organ disease are never placed on the transplant waiting list. Limited access to the transplant waiting list combined with the scarcity of the organ pool result in over 100,000 deaths annually in the United States. Patients face unique barriers to referral and acceptance for organ transplant based on social determinants of health, and patients from disenfranchised groups suffer from disproportionately lower rates of transplantation. Our objective was to review the literature describing disparities in access to organ transplantation based on social determinants of health to integrate the existing knowledge and guide future research.

Methods

We conducted a scoping review of the literature reporting disparities in access to heart, lung, liver, pancreas and kidney transplantation based on social determinants of health (race, income, education, geography, insurance status, health literacy and engagement). Included studies were categorized based on steps along the transplant care continuum: referral for transplant, transplant evaluation and selection, living donor identification/evaluation, and waitlist outcomes.

Results

Our search generated 16,643 studies, of which 227 were included in our final review. Of these, 34 focused on disparities in referral for transplantation among patients with chronic organ disease, 82 on transplant selection processes, 50 on living donors, and 61 on waitlist management. In total, 15 studies involved the thoracic organs (heart, lung), 209 involved the abdominal organs (kidney, liver, pancreas), and three involved multiple organs. Racial and ethnic minorities, women, and patients in lower socioeconomic status groups were less likely to be referred, evaluated, and added to the waiting list for organ transplant. The quality of the data describing these disparities across the transplant literature was variable and overwhelmingly focused on kidney transplant.

Conclusions

This review contextualizes the quality of the data, identifies seminal work by organ, and reports gaps in the literature where future research on disparities in organ transplantation should focus. Future work should investigate the association of social determinants of health with access to the organ transplant waiting list, with a focus on prospective analyses that assess interventions to improve health equity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01616-x.

Prevalence and Correlates of Cost-Related Medication Nonadherence to Immunosuppressive Drugs After Heart Transplantation: The International Multicenter Cross-sectional Bright Study

BACKGROUND

Cost-related medication nonadherence (CRMNA) refers to not taking medications as prescribed because of difficulties paying for them.

OBJECTIVES

The aims of this study were (1) to assess the prevalence of CRMNA to immunosuppressants in heart transplant recipients internationally and (2) to determine multilevel correlates (patient, center, and healthcare system levels) of CRMNA.

METHODS

Using data from the cross-sectional international BRIGHT study, applying multistaged sampling, CRMNA was assessed via 3 self-report items in 1365 patients from 36 heart transplant centers in 11 countries. Cost-related medication nonadherence was defined as any positive answer on any of the 3 items. Healthcare system-level (ie, insurance coverage, out-of-pocket expenditures) and patient-level (ie, intention, perceived financial burden, cost as a barrier, a health belief regarding medication benefits, cost-related self-efficacy, and demographic factors) CRMNA correlates were assessed. Correlates were examined using mixed logistic regression analysis.

RESULTS

Across all study countries, CRMNA had an average prevalence of 2.6% (range, 0% [Switzerland/Brazil] to 9.8% [Australia]) and was positively related to being single (odds ratio, 2.29; 95% confidence interval, 1.17-4.47), perceived financial burden (odds ratio, 2.15; 95% confidence interval, 1.55-2.99), and cost as a barrier (odds ratio, 2.60; 95% confidence interval, 1.66-4.07). Four protective factors were identified: white ethnicity (odds ratio, 0.37; 95% confidence interval, 0.19-0.74), intention to adhere (odds ratio, 0.44; 95% confidence interval, 0.31-0.63), self-efficacy (odds ratio, 0.54; 95% confidence interval, 0.43-0.67), and belief about medication benefit (odds ratio, 0.70; 95% confidence interval, 0.57-0.87). Regarding variability, 81.3% was explained at the patient level; 13.8%, at the center level; and 4.8%, at the country level.

CONCLUSION

In heart transplant recipients, the CRMNA prevalence varies across countries but is lower than in other chronically ill populations. Identified patient-level correlates are novel (ie, intention to adhere, cost-related barriers, and cost-related self-efficacy) and indicate patient-perceived medication cost burden.

Social Adaptability Index and Pregnancy Outcomes in Women With Diabetes During Pregnancy

OBJECTIVE

The social adaptability index (SAI) is a composite indicator capturing an individual's social adaptability within society and socioeconomic status to predict overall health outcomes. The objective of this analysis was to examine whether the SAI is an independent risk factor for adverse pregnancy outcomes in women with and without diabetes during pregnancy.

METHODS

Data from the 2011-2017 National Survey of Family Growth were analyzed using a cross-sectional methodology. Women aged 18-44 years with a singleton gestation were included in the analysis. Maternal diabetes was defined as either presence of pregestational diabetes or diagnosis of gestational diabetes. The SAI was developed from the following maternal variables: educational level, employment status, income, marital status, and substance abuse. A higher score indicated lower risk. A series of multivariable logistic regression models were run stratified by maternal diabetes status to assess the association between SAI and pregnancy outcomes, including cesarean delivery, macrosomia (birth weight ≥4,000 g) and preterm birth (<37 weeks). All analyses were weighted and P <0.05 was considered significant.

RESULTS

A total of 17,772 women were included in the analysis, with 1,965 (10.7%) having maternal diabetes during pregnancy. The SAI was lower in women with diabetes during pregnancy compared with control subjects (6.7 ± 0.2 vs. 7.2 ± 0.1, P <0.001). After adjusting for maternal race and ethnicity, insurance status, BMI, age, and partner support of the index pregnancy, SAI was associated with preterm birth among women with diabetes during pregnancy (adjusted odds ratio 0.83, 95% CI 0.72-0.94). The SAI was not significantly associated with cesarean delivery or macrosomia in women with diabetes during pregnancy and was not associated with these outcomes in women without diabetes during pregnancy.

CONCLUSION

Among women with diabetes during pregnancy, a higher SAI is independently associated with a lower risk of preterm birth. The SAI could be a useful index to identify women at high risk of preterm birth in addition to traditionally defined demographic risk groups among women with diabetes during pregnancy.

Pre-transplant Social Adaptability Index and clinical outcomes in renal transplantation: The Swiss Transplant Cohort study

BACKGROUND

The impact of pre-transplant social determinants of health on post-transplant outcomes remains understudied. In the United States, poor clinical outcomes are associated with underprivileged status, as assessed by the Social Adaptability Index (SAI), a composite score of education, employment status, marital status, household income, and substance abuse. Using data from the Swiss Transplant Cohort Study (STCS), we determined the SAI's predictive value regarding two post-transplant outcomes: all-cause mortality and return to dialysis.

METHODS

Between 2012 and 2018, we included adult renal transplant patients (aged ≥ 18 years) with pre-transplant assessment SAI scores, calculated from a STCS Psychosocial Questionnaire. Time to all-cause mortality and return to dialysis were predicted using Cox regression.

RESULTS

Of 1238 included patients (mean age: 53.8 ± 13.2 years; 37.9% female; median follow-up time: 4.4 years [IQR: 2.7]), 93 (7.5%) died and 57 (4.6%) returned to dialysis. The SAI's hazard ratio was 0.94 (95%CI: 0.88-1.01; p = .09) for mortality and 0.93 (95%CI: 0.85-1.02; p = .15) for return to dialysis.

CONCLUSIONS

In contrast to most published studies on social deprivation, analysis of this Swiss sample detected no significant association between SAI score and mortality or return to dialysis.

Health Literacy Burden Is Associated With Access to Liver Transplantation

BACKGROUND

Getting listed for liver transplantation is a complex process. Institutional health literacy may influence the ability of patients with limited educational attainment (EA) to list. As an easily accessible indicator of institutional health literacy, we measured the understandability of liver transplant center education websites and assessed whether there was any association with the percentage of low EA patients on their waitlists.

METHODS

Patients on the waitlist for liver transplantation 2007-2016 were identified in Scientific Registry of Transplant Recipients. Understandability of patient education websites was assessed using the Clear Communication Index (CCI). The Centers for Disease Control and Prevention has set itself a goal CCI of 90 as being easy to understand. Low EA was defined as less than a high school education. We adjusted for center case-mix, Donor Service Area characteristics, and EA of the general population.

RESULTS

Patients (84 774) were listed across 112 liver transplant centers. The median percent of waitlisted patients at each center with low EA was 11.0% (IQR, 6.6-16.8). CCI ranged from 53 to 88 and correlated with the proportion of low EA patients on the waitlist. However, CCI was not associated with the percentage of low EA in the general population. For every 1-point improvement in CCI, low EA patients increase by 0.2% (P < 0.05), translating to a 3.6% increase, or additional 3000 patients, if all centers improved their websites to CCI of 90.

CONCLUSIONS

Educational websites that are easier to understand are associated with increased access to liver transplantation for patients with low EA. Lowering the health literacy burden by transplant centers may improve access to the liver transplant waitlist.

Use of social adaptability index to explain self-care and diabetes outcomes

BACKGROUND

To examine whether the social adaptability index (SAI) alone or components of the index provide a better explanatory model for self-care and diabetes outcomes.

METHODS

Six hundred fifteen patients were recruited from two primary care settings. A series of multiple linear regression models were run to assess (1) associations between the SAI and diabetes self-care/outcomes, and (2) associations between individual SAI indicator variables and diabetes self-care/outcomes. Separate models were run for each self-care behavior and outcome. Two models were run for each dependent variable to compare associations with the SAI and components of the index.

RESULTS

The SAI has a significant association with the mental component of quality of life (0.23, p < 0.01). In adjusted analyses, the SAI score did not have a significant association with any of the self-care behaviors. Individual components from the index had significant associations between self-care and multiple SAI indicator variables. Significant associations also exist between outcomes and the individual SAI indicators for education and employment.

CONCLUSIONS

In this population, the SAI has low explanatory power and few significant associations with diabetes self-care/outcomes. While the use of a composite index to predict outcomes within a diabetes population would have high utility, particularly for clinical settings, this SAI lacks statistical and clinical significance in a representative diabetes population. Based on these results, the index does not provide a good model fit and masks the relationship of individual components to diabetes self-care and outcomes. These findings suggest that five items alone are not adequate to explain or predict outcomes for patients with type 2 diabetes.

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.

Do Federal Regulations Have an Impact on Kidney Transplant Outcomes?

Transplantation is one of the most highly regulated fields in health care. An important component of transplant oversight is the performance assessment of transplant centers as measured by 1-year patient and graft survival outcomes. The use of the Organ Procurement and Transplantation Network and Scientific Registry of Transplant Recipients flagging mechanism for quality improvement as criteria for Center for Medicare and Medicaid Services certification has resulted in greater importance in transplant program operations. Although supporters of this program of encouraging Quality Assurance and Performance Improvement point to improved survival outcomes for more than the decade, others assert that the oversight is unnecessarily punitive, results in tremendous resource utilization, and discourages innovation. Data exist to support an inhibitory effect on national transplant volume. Although survival outcomes are risk adjusted, limitations on national data collection prevent several important risks from being incorporated into the models. This has led to the consensus that many transplant centers have become increasingly risk averse in this environment, which may indirectly reduce access to transplant for candidates who could still benefit from transplantation. Recently enacted modifications to performance evaluation by Center for Medicare and Medicaid Services and the Organ Procurement and Transplantation Network appear to acknowledge these concerns and have the potential to recalibrate transplant center focus away from first-year outcomes and more toward expanding transplant volume, innovation, and overall improvements in care.

Influence of Socio-Economic Inequalities on Access to Renal Transplantation and Survival of Patients with End-Stage Renal Disease

Background

Public and scientific concerns about the social gradient of end-stage renal disease and access to renal replacement therapies are increasing. This study investigated the influence of social inequalities on the (i) access to renal transplant waiting list, (ii) access to renal transplantation and (iii) patients’ survival.

Methods

All incident adult patients with end-stage renal disease who lived in Bretagne, a French region, and started dialysis during the 2004–2009 period were geocoded in census-blocks. To each census-block was assigned a level of neighborhood deprivation and a degree of urbanization. Cox proportional hazards models were used to identify factors associated with each study outcome.

Results

Patients living in neighborhoods with low level of deprivation had more chance to be placed on the waiting list and less risk of death (HR = 1.40 95%CI: [1.1–1.7]; HR = 0.82 95%CI: [0.7–0.98]), but this association did not remain after adjustment for the patients’ clinical features. The likelihood of receiving renal transplantation after being waitlisted was not associated with neighborhood deprivation in univariate and multivariate analyses.

Conclusions

In a mixed rural and urban French region, patients living in deprived or advantaged neighborhoods had the same chance to be placed on the waiting list and to undergo renal transplantation. They also showed the same mortality risk, when their clinical features were taken into account.

The role of disparities and socioeconomic factors in access to kidney transplantation and its outcome

BACKGROUND

Research focused on identifying vulnerable populations and revealing specific risk factors for barriers along the pathway from ESRD to kidney transplantation has been mostly descriptive and the causes of existing disparities remain unclear. However, several socio-economic factors that are associated with the access to and the outcome of the kidney transplantation have been identified.

SUMMARY

While the presence of racial, gender, and geographic disparities is noted, we were interested mostly to describe potential socio-economic factors associated with and possibly responsible for the presence of such disparities. In this review we focused on five factors: education level, employment status, income, presence of substance addiction or abuse, and marital status. We describe the new method to quantify patients' socio-economic status and identify the group of high risk in terms of the transplant outcome, easily calculated social adaptability index, previously associated with clinical outcome in several patient populations including those with kidney transplant. At the end, based on literature analyzed we offer potential interventions that potentially can be used in order to reduce the degree of disparities.

CONCLUSION

Based on review of literature socio-economic factors are associated with and possibly responsible for healthcare disparities. Social adaptability index allows quantifying the degree of socio-economic status and identifying the group of high risk for inferior transplant outcome.

Kidney transplant access in the Southeastern United States: the need for a top-down transformation

End-stage renal disease (ESRD) and poverty are highly prevalent conditions in the Southeastern United States. The American Southeast also has some of the lowest attainments of health status among its constituents. Transplantation rates are particularly low in the Southeast compared with other regions of the United States. These low kidney transplantation rates in the Southeast likely reflect poor access to medical care. This disproportionate lack of access to medical care among ESRD patients in the Southeast reflects the convergence and interaction of socioeconomic and biologic forces at the patient level interacting with the financial and organizational structure of the health-care system. Improving kidney transplant access in the Southeast will take disruptive political, financial and health system changes whose scope transcends transplant centers and dialysis units.

Recipient's unemployment restricts access to renal transplantation

Equitable distribution of a scarce resource such as kidneys for transplantation can be a challenging task for transplant centers. In this study, we evaluated the association between recipient's employment status and access to renal transplantation in patients with end-stage renal disease (ESRD). We used data from the United States Renal Data System (USRDS). The primary variable of interest was employment status at ESRD onset. Two outcomes were analyzed in Cox model: (i) being placed on the waiting list for renal transplantation or being transplanted (whichever occurred first); and (ii) first transplant in patients who were placed on the waiting list. We analyzed 429 409 patients (age of ESRD onset 64.2 ± 15.2 yr, 55.0% males, 65.1% White). Compared with patients who were unemployed, patients working full time were more likely to be placed on the waiting list/transplanted (HR 2.24, p < 0.001) and to receive a transplant once on the waiting list (HR 1.65, p < 0.001). Results indicate that recipient's employment status is strongly associated with access to renal transplantation, with unemployed and partially employed patients at a disadvantage. Adding insurance status to the model reduces the effect size, but the association still remains significant, indicating additional contribution from other factors.

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.

Access to renal transplantation in the diabetic population-effect of comorbidities and body mass index

BACKGROUND

In this study, we hypothesized that higher level of comorbidity and greater body mass index (BMI) may mediate the association between diabetes and access to transplantation.

METHODS

We used data from the United States Renal Data System (01/01/2000-24/09/2007; n = 619,151). We analyzed two outcomes using Cox model: (i) time to being placed on the waiting list or transplantation without being listed and (ii) time to transplantation after being listed. Two primary Cox models were developed based on different levels of adjustment.

RESULTS

In Cox models adjusted for a priori defined potential confounders, history of diabetes was associated with reduced transplant access (compared with non-diabetic population) - both for wait-listing/transplant without being listed (hazard ratio, HR = 0.80, p < 0.001) and for transplant after being listed (HR = 0.72, p < 0.001). In Cox models adjusted for BMI and comorbidity index along with the potential confounders, history of diabetes was associated with shorter time to wait-listing or transplantation without being listed (HR = 1.07, p < 0.001), and there was no significant difference in time to transplantation after being listed (HR = 1.01, p = 0.42).

CONCLUSION

We demonstrated that higher level of comorbidity and greater BMI mediate the association between diabetes and reduced access to transplantation.