Date of Award

January 2016

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Christopher Tormey

Second Advisor

Alexa Siddon


An evaluation of the APC resistance and factor five Leiden testing at our hospital between 2010 and 2015 was undertaken. An overabundance of factor five Leiden gene mutation testing and corresponding financial ramifications were considered. Specifically, over 90% of all factor five Leiden mutation tests were negative, representing a potential annual savings of over $40,000. It was also noted that quantitative APC resistance values are directly related to the factor five Leiden genotype. Patients with non-Leiden APC resistance had significantly higher values for APC resistance (1.85 vs. 1.97 with p < 0.005). Discordance between APC resistance testing and factor five Leiden testing was also examined, and autoimmune disease and liver transplantation emerged as common associations. Based on these observations, we propose specific modifications to the thrombophilia diagnostic algorithm that we believe will decrease cost and increase diagnostic clarity.


This thesis is restricted to Yale network users only. It will be made publicly available on 08/23/2018.