Keren Ladin

Keren Ladin

Associate Professor, Dept of Occupational Therapy and Dept of Community Health, Tufts University
Associate Professor, Dept of Public Health and Community Medicine, Tufts University School of Medicine

Dissertation Title:  "Empirical and Normative Implications of Social Networks for Health Disparities: The Case of Renal Transplantation"

The objective of this dissertation is to examine to what extent individual-level or social network-level characteristics explain disparities in living donor kidney transplantation, and to consider the moral implications of social network effects on resource allocation for vulnerable populations.

Paper One examines whether patient characteristics explain racial disparities in the rate of donor presentation and living donor kidney transplantation (LDKT) in a sample of 752 potential kidney recipients and 654 potential kidney donors. Even after propensity score matching and subclassification were used to redistribute the patient characteristics by race, survival models revealed that disparities in time to first donor persisted. Only 24% of blacks compared to 39% of whites would have at least one potential donor evaluated within the first year, even after accounting for differences in the distribution of patient characteristics. We conclude that lower rates of donor presentation among black recipients cannot be explained by differences in individual-level characteristics.

Paper Two examines whether differences in social networks account for disparities in LDKT. We interviewed and reviewed medical records from a representative sample of 389 dialysis patients in the Greater Boston area and a subsample of 302 alters about the role of social networks in their decision-making surrounding transplantation. Some social network characteristics, in particular network size, were strongly predictive of patients’ ability to pursue LDKT. Despite limited patient level differences, significant racial disparities in health status and medical distrust among social networks of black patients present compelling evidence for network effects. Compositional differences in the health of social networks of Black patients suggest that fewer network members may be eligible for LDKT, and those who are eligible may be less willing due to greater distrust or face more systemic barriers owing to poor socioeconomic position.

The third paper examines the moral relevance of social networks for resource allocation. In particular, it examines whether society ought to be concerned with disparities in transplantation as availability of transplants is an intermediary step to addressing broader health disparities. This paper argues that society ought to be concerned with previously neglected disparities in LDKT, specifically the fraction stemming from disparities in social networks because networks provide one pathway by which inequalities can be perpetuated throughout society and over time. Insofar as social networks are influenced by an unjust distribution of social forces, and social networks influence life chances by limiting or enhancing a patient’s ability to obtain a LDKT, then life chances of dialysis patients are influenced by an unjust distribution of social forces via a social network mechanism. Finally, this paper explores potential policies aimed at providing compensatory damages to patients whose networks have been adversely affected by the unjust influence of social determinants.


Graduation Year