📄 medicine

General Surgery Residency Expansion Does Not Systematically Scale with Population Growth Across U.S. Regions: A National Analysis, 2013–2024

A national analysis from 2013 to 2024 reveals that the allocation of general surgery residency positions across U.S. regions does not systematically scale with population growth, resulting in significant regional disparities in training workforce distribution.

Original authors: Zeran Zhang, Luke Phillips, Elizabeth Dauer

Published 2026-07-03

📖 5 min read🧠 Deep dive

CC BY 4.0

Original authors: Zeran Zhang, Luke Phillips, Elizabeth Dauer

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine the United States as a giant pizza delivery service. The "pizza" is the training spots available for future general surgeons (residency positions), and the "customers" are the people living in different parts of the country who need those surgeons.

This study, looking at data from 2013 to 2024, asks a simple question: As the number of customers (people) grows in a specific neighborhood, does the pizza shop (the residency program) automatically open more spots to serve them?

Here is the breakdown of what the researchers found, using everyday comparisons:

The Big Picture: The Mismatch

The short answer is no. The study found that the number of training spots for surgeons isn't growing in sync with where people are moving or how populations are changing.

The National Trend: Across the whole country, the number of training spots per person grew a tiny bit (about 1.35%), while the population grew a very small amount (0.48%).
The Problem: Even though the average looks okay, the distribution is all over the place. It's like if the pizza shop in one city doubled its delivery drivers while the shop in a neighboring city with a booming new neighborhood kept its staff exactly the same, or even cut back.

The Regional "Weather Report"

The researchers divided the U.S. into different regions (like New England, the South, the Midwest, etc.) and found that the "weather" for training spots was very different in each place:

The "Growing Pains" Areas: In places like the Mid-Atlantic, South Atlantic, and parts of the Midwest, the number of training spots per person actually went up significantly. It's as if these neighborhoods were finally getting more delivery drivers to match their growing populations.
The "Shrinking" Area: In New England (the Northeast), the number of training spots per person actually went down. This is interesting because this area has historically had the most training spots. The study suggests this might be a slow correction, as the population there isn't growing as fast as the number of spots, but it highlights that the system isn't automatically adjusting.
The "Disconnect" Areas: In some regions, like the East South Central (Alabama, Kentucky, Mississippi, Tennessee), the relationship was negative. This means that as the population in these areas grew, the number of training spots per person actually went down or stayed flat. It's like a town getting bigger but the local school losing seats.

The Correlation: Do They Move Together?

The researchers tried to see if the two lines (population growth and training spot growth) moved in the same direction.

The Best Match: In the East North Central region (Illinois, Indiana, Michigan, Ohio, Wisconsin), the two lines moved somewhat together. When the population grew, the training spots tended to grow too.
The Worst Match: In the East South Central region, the lines moved in opposite directions.
The National Reality: When you look at the whole country as one big group, there is no clear connection. The growth of training spots does not systematically follow the growth of the population.

Why Does This Matter? (According to the Paper)

The paper explains that where a surgeon trains is a huge clue about where they will eventually work. If you train in a rural area, you are more likely to practice in a rural area.

Because the training spots aren't moving to where the people are moving, we are creating a "maldistribution."

Urban Centers: Often have too many training spots relative to their current population needs.
Rural/Growing Areas: Often have too few training spots, even though they have older populations and a shortage of doctors.

The Proposed "Fixes" in the Paper

The authors suggest that we need to stop letting the training spots stay stuck in their old locations (like anchors on the ocean floor) and start moving them based on where people actually live. They specifically mention:

Federal Grants: Programs like the "Rural Residency Planning and Development" (RRPD) which help start new training programs in rural areas.
State Medicaid Money: States can use their own Medicaid funding rules to pay for more training spots in rural areas, rather than relying only on federal Medicare money which is capped and stuck in old locations.

The Limitations (What the Paper Didn't Say)

The authors are careful to note what they don't know:

They looked at the start of the training (the first year), not where the surgeons ended up working.
They didn't account for people dropping out of training or becoming specialists in other fields.
They can't prove that the population growth caused the lack of spots; they just showed the two things aren't moving together.
The data covers 2013–2024, which includes the pandemic, a time when things were chaotic and hard to predict.

The Bottom Line

The study concludes that the U.S. system for training new general surgeons is not automatically adjusting to population changes. It's like a map that hasn't been updated in years: the cities have grown, but the delivery routes (training spots) are still drawn for the old map. To fix the shortage of surgeons in the places that need them most, the system needs to be intentionally redesigned to match where the people actually are.

Technical Summary: General Surgery Residency Expansion Does Not Systematically Scale with Population Growth Across U.S. Regions (2013–2024)

Problem Statement
The United States is facing a general surgery workforce crisis driven by an aging surgeon population and inadequate replacement rates, a burden disproportionately felt in rural regions. While residency training is the primary mechanism for replenishing this workforce, general surgery positions remain heavily concentrated in urban academic centers. Previous literature indicates that rural training exposure during residency increases the likelihood of graduates practicing in rural areas, suggesting that the geographic allocation of training positions is as critical as the total number of positions. However, the relationship between regional residency training capacity and regional population dynamics has not been systematically examined. Specifically, it remains unclear whether the expansion of general surgery residency positions across U.S. regions aligns with corresponding population growth, or if disparities in training allocation are widening relative to demographic shifts.

Methodology
This study conducted a retrospective observational analysis of publicly available data spanning 2013 to 2024.

Data Sources: The authors utilized data from the National Resident Matching Program (NRMP) for filled PGY-1 general surgery positions and the U.S. Census Bureau for state-level population estimates.
Geographic Scope: The analysis aggregated data into nine U.S. Census Bureau divisions: New England, Mid-Atlantic, East North Central, West North Central, South Atlantic, East South Central, West South Central, Mountain, and Pacific.
Metrics: The "general surgery resident workforce" was approximated by the number of entering residency positions (SurgPGY1) per capita.
Statistical Analysis:
- Linear regression was used to model trends in positions per capita over time for each region.
- Year-over-year percentage changes in residency positions per capita were calculated and compared against percentage changes in population using paired t-tests.
- Pearson correlation coefficients were computed to assess the linear relationship between workforce allocation changes and population growth changes at both the regional and national levels.
- Statistical significance was defined as $p < 0.05$ .

Key Results

National Trends: From 2013 to 2024, the national mean percentage change in entering residency positions per capita was 1.35%, compared to a 0.48% growth in population. However, there was no significant difference between workforce and population changes when analyzed nationally or across regions individually ( $p > 0.05$ ).
Regional Heterogeneity:
- Significant Growth: The Mid-Atlantic, East North Central, South Atlantic, and Mountain regions demonstrated statistically significant increases in residency positions per capita.
- Significant Decline: The New England region exhibited a significant decline in positions per capita ( $R^2=0.75, p=0.0001$ ).
- No Significant Trend: The West North Central, East South Central, West South Central, and Pacific regions showed no statistically significant linear trends in per capita positions.
Correlation Analysis: The alignment between workforce expansion and population growth varied significantly by region:
- East North Central: Showed a moderate positive correlation ( $r=0.63, p=0.028$ ), suggesting relative alignment between training capacity and population growth.
- East South Central: Showed a moderate negative correlation ( $r=-0.57, p=0.051$ ), indicating a divergence where residency positions may be stagnating or contracting despite population growth.
- National Level: There was no significant correlation between changes in residency positions per capita and population growth nationally ( $r=0.05, p=0.884$ ).

Key Contributions
This study provides the first longitudinal, population-adjusted analysis of general surgery residency position allocation across U.S. Census regions over an 11-year period. The primary contribution is the quantification of the lack of systematic scaling between residency pipeline growth and population dynamics. By demonstrating that regional workforce expansion does not mirror regional population growth, the paper highlights that current training capacity expansion is not strategically calibrated to meet evolving geographic demands. The analysis identifies specific regions (e.g., East South Central) where the divergence between training capacity and demographic need is most pronounced, contrasting with regions where alignment is observed (e.g., East North Central).

Significance and Claims
The authors conclude that U.S. general surgery resident workforce allocation from 2013 to 2024 varies by Census Bureau region and does not systematically scale with population growth. The study claims that this heterogeneity highlights regional disparities in training environments and access to surgical care.

The paper posits that the observed trends reflect historical institutional concentrations and federal funding caps (specifically Medicare GME funding enacted in the late 1990s) that have entrenched maldistribution, preventing the training pipeline from responding to population shifts toward the South and West. The authors argue that workforce planning must incorporate population-adjusted metrics. They suggest that policy interventions, such as leveraging Medicaid GME payments at the state level to fund rural training sites and adjusting federal caps to reflect population needs, could help realign the training pipeline with geographic realities. However, the authors explicitly note limitations, including the use of Census division-level data which may obscure intra-regional urban-rural variations, the use of entering positions as a proxy without accounting for attrition or fellowship subspecialization, and the inability of correlation analysis to establish causation. The study does not claim to have solved the workforce crisis but rather provides evidence that the current expansion of residency positions is not systematically addressing the geographic misalignment of surgical workforce needs.