Linchpin score

Linchpin score is a network measure developed by our group to identify physicians who are locally unique, or linchpins, in their networks. Linchpin score captures the extent to which a physician is the only one of their specialty among their neighbors’ ties. The value ranges from 0 to 1, with 0 indicating all of the focal physician’s neighbors are connected to another physician with same specialty as the focal physician, and 1 indicating none of them are connected to another physician with the same specialty as the focal physician. Physicians with high linchpin score would not be easily replaced by another physician of the same specialty if they were to leave the network. The R code to calculate linchpin score for any network dataset with node attributes can be found here.

Related publications

Liu YC, Schmidt RO, Kapadia NS, Phillips JD, Moen EL. Disparities in access to multidisciplinary cancer consultations and treatment for early-stage non-small cell lung cancer patients: A SEER-Medicare analysis. Int J Radiat Oncol Biol Phys. 2024 Mar: Online ahead of print.

Moen EL, Schmidt RO, Onega T, Brooks GA, O’Malley AJ. Association between a network-based physician linchpin score and cancer patient mortality: A SEER-Medicare analysis. J Natl Cancer Inst. 2024 Feb;116(2):230-238.

Moen EL, Brooks GA, O’Malley AJ, Schaefer A, Carlos HA, Onega T. Use of a novel network-based linchpin score to characterize accessibility to the oncology physician workforce in the United States. JAMA Network Open. 2022;5(12):e2245995.

Nemesure MD, Schwedhelm TM, Sacerdote S, O’Malley AJ, Rozema LR, Moen EL. A measure of local uniqueness to identify linchpins in a social network with node attributes. Applied Net Sci. 2021 Aug; 6(56).

Linchpin score maps

An example of geographic variation in physician linchpin score is shown below. We’ve mapped hospital referral region (HRR)-level network vulnerability for radiation oncology, or the proportion of radiation oncologists who are linchpins in each HRR.

Data sources

  • Medicare data as approved by DUA 57615.