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Updated: Aug 24, 2025
A Large Lateral Craniotomy Procedure for Mesoscale Wide-field Optical Imaging of Brain Activity
Published on: May 7, 2017
79 is the new 70: Left digit bias in craniotomy
Allison Blumenfeld1, Hilla I Sang2, Rebecca Baird2
1University of South Dakota Sanford School of Medicine General Surgery Residency, Health Science Center, 1400 W 22nd St, Sioux Falls, SD, 57105, USA.
Background:
Left digit bias is the psychological phenomenon in which the difference between values is perceived as larger due to the value of the first digit. For example, an 80 year old may be perceived as much older than a 79 year old. We sought to determine if left digit bias is present in craniotomy for elderly patients with traumatic brain injury.
Methods:
Patients aged 69, 70, 79, and 80 with traumatic brain injury and an abbreviated injury scale severity of a minimum of 3 were included from the National Trauma Data Bank from the years 2012-2019. 38,908 patients were included. A Chi-squared Test was performed to compare the percentage of patients undergoing craniotomy.
Results:
79 year olds had higher craniotomy rates than 80 year olds (7.8% vs 6.4%, P < 0.001). There was no difference in craniotomy rates between 69 and 70 year olds (8.2% vs 7.8%, P < 0.2622).
Conclusion:
This study suggests the presence of left digit bias in the decision to perform a craniotomy in patients aged 79 vs 80 with traumatic brain injury.
