Estimating the demand for and supply of an appropriate number of physicians, and planning for their adequate provision, is crucial for the proper functioning of healthcare services.

This study was conducted to determine whether the current number of physicians is adequate to meet the needs of a future society, considering that social changes, such as demographic shifts, are expected to increase medical demand. Thus, instead of evaluating whether the current physician workforce is excessive or insufficient, this study projects the future physician workforce based on the assumption that the number of physicians in 2018 was appropriate.

This study does not involve human subjects. Therefore, approval by the institutional review board and the acquisition of informed consent were not required.

This study is a simulation based on various data sources, including the Health Insurance Statistical Yearbook, the Report of Statistics Korea, and the number of physicians in Korea.

Since medical demand reflects the population's use of medical services, we utilized data from the 2018 Health Insurance Statistical Yearbook to calculate per capita outpatient and inpatient utilization by age and gender. We then used population projection data from Statistics Korea (2017–2067) to estimate medical demand. Assuming a workload ratio of 1:3 between outpatient and inpatient services, we multiplied the outpatient demand by 3 to estimate the total demand.

For the supply side, we estimated the number of physicians based on medical school quotas using a cohort-component algorithm. We assumed a 95% pass rate for students taking the national medical licensing examination, allowing for those who were unsuccessful to retake the exam in subsequent years. We made projections by age groups (20s, 30s, 40s, 50s, 60s, 65s, 70s), using the mortality rates for each age group from 2018 Statistics Korea data to calculate attrition rates. The retirement age was set at 75 years.

To calculate the balance between supply and demand, we first needed to quantify medical demand in terms of the number of physicians required to meet it. We estimated the daily workload for each physician, based on the assumption that they work 265 days per year, using data from 2018. For physicians aged 65 to 75, we adjusted their expected daily productivity to 50% of that of their younger colleagues in Scenario 1, and to 75% in Scenario 2. Additionally, we factored in an annual increase of 0.5% in the daily work capacity of a physician, attributing this improvement to technological advancements. With these calculations, we determined the required number of physicians each year and compared it to the projected physician supply for that year.

Regional data were categorized into two groups: by province and by secondary medical service area. Physician supply projections utilized age-specific physician data from either the province or the secondary medical service area, as specified in the 2016 data from the Ministry of Health and Welfare. Medical demand for each province was estimated using population projections from Statistics Korea for the years 2017 to 2047. As there were no distinct projections available for secondary medical service areas, the 2018 population ratios were applied to the national projections.

The projection of physician workforce supply and demand by region revealed that Seoul had the highest concentration of physicians, with a ratio exceeding 1.14–1.16 physicians per 1,000 population as of 2018. In contrast, regions such as Chungcheong, Jeolla, Gyeongsang Provinces, and Jeju Island had fewer than 1 physician per 1,000 population. Given the current trends, by 2047, these regions are expected to face a more severe shortage of physicians.

In an analysis of 56 secondary medical service areas, Hongseong was identified as having the most significant physician shortage in 2018, with approximately 1.58 fewer physicians per 1,000 people than the national average. This shortage was closely followed by Mungyeong and Sokcho, each with a deficit of 1.45 physicians per 1,000 population, Sacheon with 1.42, and both Jincheon and Andong with 1.40. On the other hand, Seoul had the highest surplus of physicians in 2018, with about 1.02 more physicians per 1,000 population than the national average. Following Seoul were Yangsan with 0.64 additional physicians per 1,000 population, Bucheon with 0.21, Gwangju with 0.18, and Busan with 0.16.

In 2018, most secondary medical service areas in metropolitan cities had an excess of physicians, whereas areas experiencing a shortage of physicians were predominantly found in the Chungcheong, Jeolla, and Gangwon regions.

Assuming no increase in medical school quotas, projections for the physician supply and demand in 2035 suggest a deepening shortage in Hongseong, which already had the most significant shortage in 2018. By 2035, the shortage is expected to reach approximately 2.29 physicians per 1,000 population. Following closely are Mungyeong, with a projected shortage of 2.19 physicians per 1,000 population, Andong with 2.12, Sacheon with 2.10, and Sokcho with 2.04, all of which are anticipated to experience worsening shortages compared to 2018. Conversely, areas like Seoul, Yangsan, Bucheon, Suwon, and Cheonan are expected to have an excess of physicians. The surplus is particularly notable in Seoul and Yangsan, where the excess is predicted to exceed 1.41 and 1.12 physicians per 1,000 population, respectively, relative to 2018.