Background
In order to provide nursing services that will ensure patient safety, medical institutions should have a sufficient number of nurses [
1,
2]. Some countries stipulate a maximum number of patients to be assigned to one nurse. The average nurse-to-patient ratio is less than 1:4 in Australia and 1:5 in California [
1]. In medical institutions, increased levels of nurse staffing can lower patient mortality, reduce patients’ length of stay, promote patient safety, and boost patient satisfaction [
3‐
5]. In contrast, insufficient nurse staffing has a negative impact on work-related stress, job satisfaction, desire to change careers, and instances of infection exposure [
6]. Ensuring a sufficient number of nurses has a positive effect on hospital financial performance by increasing profitability and reducing expenditures, such as nurse turnover and associated costs [
7,
8].
Because healthcare is a basic human need and public good, the operation of medical institutions should not be entirely entrusted to market forces [
9]. For example, if a medical institution autonomously determines the level of medical personnel without government guidelines, a situation could arise in which the institution deploys the minimum number of nurses to care for the maximum number of patients to reduce nurses’ labor costs, which constitute a significant proportion of the expenditure [
7,
10]. Government regulations or guidelines are required because natural monopolies and market failures may occur in medical and public health systems [
11]. The government of each country, therefore, focuses on the development of policy and legislation to ensure appropriate nurse staffing in medical institutions [
12,
13].
Since 1999, one of the government interventions for nurse staffing in Korea has been the nursing fee differentiation policy, which differentiates support for inpatient nursing fees based on nurse staffing grades [
14]. The nurse staffing grade of the Korean policy refers to the nurse staffing ratio. Nurse staffing grades were measured by the ratio of nurses to beds (or patients) according to the type of hospital and department. The nurse staffing grades were classified from grade 1 (the best) to grade 7 (the worst) and were calculated by dividing the average number of beds (or patients) over the past three months (as of the 15th of each month) by the average number of nurses over the same period. The number of nurses applied to the nurse staffing grades excludes nurses who are not engaged in patient care and includes only nurses who actually provide patient care in wards and intensive care units (ICUs). When calculating nurse staffing grades, the severity of patients’ conditions or the acuity of illness was not adjusted within the same ward or ICU, but different grading standards were applied to general wards and ICUs, respectively. For example, in the case of a general ward, grade 1 (the best) means that the number of beds (or patients) per nurse must be less than 2.5, but in the case of an ICU, the number must be less than 0.5. Further, even in the same general ward, in the case of a tertiary hospital that cares for patients with high-disease severity, grade 1 means that the number of beds (or patients) per nurse is less than 2.0 [
15]. Medical institutions are required to report their nurse staffing grades to the government every quarter.
The nursing fee differentiation policy was introduced in Korea medical institutions lacking sufficient nurse staffing levels to address the issue of the deteriorating quality of nursing services for inpatients, such as partial nursing service omission or delegation of nursing services to guardians or caregivers [
16]. The nursing fee differentiation policy is a financial incentive reimbursement system, in which inpatient nursing fees increase by a certain percentage as the nursing staff level increases.
Korea has the National Health Insurance (NHI) healthcare system operated by the government insurer, NHI Service (NHIS) [
17]. When inpatients use the service of a hospital, they pay 5–20% of the total medical expenses directly to the hospital as a co-payment, and the hospital bills the NHIS for the remaining amount and is reimbursed [
18]. All citizens pay approximately 7% of their monthly income as insurance contributions every month. In Korea, a fee-for-service model basically determines the cost of healthcare services, and hospitalization fees are charged separately per inpatient per day. The inpatient nursing fee constitutes a certain percentage of hospitalization fees and the inpatient nursing fee is affected by nurse staffing grades. If the hospital’s nurse staffing grade is 1, the hospital will reimburse all inpatient nursing fees and certain extra financial incentives. In the case of hospitals with a nurse staffing grade of 7, reduced inpatient nursing fees will be reimbursed [
19].
This nursing fee differentiation policy was initially applied to general wards (Table
1) and then expanded to ICUs by the Korean government. However, contrary to the policy intention that medical institutions would voluntarily increase nurse staffing levels, small- and medium-sized regional hospitals renounced financial incentives, received only minimum base inpatient nursing fees, and did not hire additional nurses. Accordingly, from 2007, the Korean government adopted a disincentive policy that reduced inpatient nursing fees by 2–5% for medical institutions that did not maintain basic nurse staffing levels [
14].
Table 1
The criteria for the nursing fee differentiation policy by nursing staffing ratios of general wards
Grade 1 | < 2.5 | Increase of 10% from grade 2 | Increase of 10% from grade 2 |
Grade 2 | ≤ 2.5 and < 3.0 | Increase of 10% from grade 3 | Increase of 10% from grade 3 |
Grade 3 | ≤ 3.0 and < 3.5 | Increase of 15% from grade 4 | Increase of 10% from grade 4 |
Grade 4 | ≤ 3.5 and < 4.0 | Increase of 10% from grade 5 | Increase of 10% from grade 5 |
Grade 5 | ≤ 4.0 and < 4.5 | Increase of 10% from grade 6 | Increase of 20% from grade 6 |
Grade 6 | ≤ 4.5 and < 6.0 | Reference grade | Reference grade |
Grade 7 | ≥ 6.0 | Reduction of 2–5% of grade 6 | Reduction of 2–5% of grade 6 |
Nevertheless, the nursing fee differentiation policy had little effect as an incentive on the improvement of nurse staffing levels, and the method used to calculate nurse staffing grades was identified as one of the causes of the problem. In early years, the nursing fee differentiation policy used the nurse-to-bed ratio to calculate nurse staffing grade. Since this calculation method is based on the number of beds regardless of the number of patients for whom nurses actually cared, a problem emerged—namely, in medical institutions with low bed utilization, there was no major change in the nurse staffing grade, even if the quality of care was improved by hiring additional nurses, and the cost of hiring additional nurses increased without any corresponding increase in reimbursement [
20].
Finding nurses for small- and medium-sized regional hospitals has become difficult owing to expectation of high wages among new nurses who enter the medical field, their preference for working in large hospitals, and their tendency to avoid working in less populous regions. Therefore, the need to improve the existing calculation method for the nurse staffing grade emerged [
21,
22]. Accordingly, in 2017, the Korean government proposed a revised plan to change the method of calculating nurse staffing grades from the nurse-to-bed ratio to the nurse-to-patient ratio [
21].
As of April 1, 2018, this revised method of calculation was adopted in medical institutions in small- and medium-sized cities and rural areas, as well as in some medical institutions established in accordance with certain legislation (first stage of application). The revised calculation method aimed to resolve the disadvantages of the low bed utilization rate in medical institutions in small- and medium-sized cities and rural areas and to enhance the treatment of nurses by providing additional nursing fee compensation (revenue) for hospitals with higher nurse staffing grades [
23]. Through this reform, the Korean government attempted to solve the difficulties of medical institutions in securing nurses in small- and medium-sized cities and rural areas. In 2020, all nationwide medical institutions were subject to the revised calculation method for nurse staffing grades, except for tertiary medical institutions (45 nationwide as of 2021) and medical institutions located in the capital, Seoul (second stage of application). Tertiary medical institutions and institutions located in the capital were excluded because they had a high bed utilization rates and less difficulty securing nurses.
Securing a sufficient number of medical personnel is recognized as a key factor in operating medical institutions and navigating the healthcare system [
24]. Nurses are important personnel in medical institutions. Incentive policies and regulations at the government level are essential for securing and retaining the sufficient number of nurses to meet patients’ needs in medical institutions in small- and medium-sized cities and rural areas, which face major difficulties providing sufficient nurses [
14]. In 2004, California introduced legislation mandating a minimum nurse-to-patient ratio, which increased the level of nurse staffing in medical institutions and direct nursing time [
25]. In Australia, medical institutions that implemented mandatory regulations for a minimum nurse-to-patient ratio acquired more nurses than those that did not implement these regulations. They also reported improvements in patients’ health indicators such as mortality, readmission rate, and the length of hospital stay [
12].
The nursing fee differentiation policy, based on nurse staffing grades calculated using the nurse-to-bed ratio, improved nurse staffing levels in many large medical institutions in large cities [
26], whereas the effect of this policy on local small- and medium-sized hospitals was insignificant. In 2018 and 2020, the Ministry of Health and Welfare switched the method for calculating nurse staffing grades to the nurse-to-patient ratio to improve the nursing fee differentiation policy, which had stagnated as a financial incentive to secure nurses. However, in Korea, the period of nursing education an individual required to become a nurse had been unified into a four-year bachelor's degree program in 2011. Thus, as of 2024, all universities and colleges offered nursing education as a 4-year bachelor's program, instead of dividing it into a 3-year diploma program and a 4-year bachelor's program [
27]. Further, unlike foreign cases with various types of nursing personnel, the main nursing personnel in Korean general hospitals are all registered nurses (RNs). Therefore, the nursing-fee differentiation policy is also based on the number of RNs per patient (or bed). Therefore, following the direction of Korea’s nursing education, this policy aimed to reduce the number of patients per nurse by increasing the number of nurses caring for patients without considering their educational background.
The study aimed to examine the impact of the nursing fee differentiation policy, which changed the nurse-to-bed ratio to the nurse-to-patient ratio, on the improvement of nurse staffing grades (referring to ratio) in medical institutions.
Methods
Study design
This prospective cohort study used national-level secondary data to assess the impact of the revised nursing fee differentiation policy based on the nurse-to-patient ratio on changes in nurse staffing grades in medical institutions. However, since nurse staffing grade is a term used in Korea, nurse staffing ratio replaced it to improve international understanding. In other words, the nurse staffing ratio described in this study refers to the Korean nurse-staffing grade, which ranges from one to seven. This study was designed, analyzed, and described in accordance with STROBE guidelines.
Participants and data sources
This study began by building a prospective cohort in the second quarter of 2017 and completed the cohort construction in the second quarter of 2021. We collected data on the nurse staffing ratio of general ward; the type of hospital and establishment; location; and the number of beds, physicians, and medical equipment for all 1,806 hospital-level medical institutions in Korea. These data were collected from the website of Health Insurance Review & Assessment (HIRA) Service via the “Find hospitals and pharmacies” menu [
28]. The HIRA reviews the claims and assesses the quality of health care services. The HIRA sets the scope and standards of services covered by NHI, efficiently manages healthcare resources, and evaluates the cost and quality of healthcare services. All medical institutions were required to submit claims and hospital information to the HIRA. Using this information, the HIRA provides the latest updated basic hospital information (operation hours, the number of beds, medical departments, number of physicians, emergency room operations, medical equipment, and nurse staffing ratio), hospital evaluation information (results of evaluating hospital medical services, including surgery, disease, and drug use from medical/pharmaceutical and cost-effective aspects), and medical expenses information. All citizens had real-time access to data on the HIRA website. This study used these data to analyze changes in nurse staffing ratios according to changes in nursing fee differentiation policy.
The following medical institutions were excluded from our study: 1) those that focused on special patients such as military hospitals, police hospitals, and national Hansen’s disease hospitals, because these hospitals operate for special purposes without any medical profits unlike general hospitals. They receive medical expenses from the government, military, and civil servant organizations, rather than from patients; therefore, financial-incentive policies may not generally affect them. Further, the nursing staff at military hospitals consists of nursing officers who are military personnel; so there is the difference of the supply and demand of nursing staff at general hospitals; 2) institutions that carry descriptions, such as “nursing home,” “rehabilitation,” “geriatric,” and “psychiatric,” in their names, or those that functioned minimally as acute care hospitals by providing internal surgery because the number of beds in closed psychiatric wards accounted for more than 50% of the number of beds in general wards; 3) those that had changed their hospital type to clinics or convalescent hospitals; 4) those that were newly established or closed during the study period; and 5) tertiary hospitals. Even if the name of a medical institution changed during the prospective cohort period, medical institutions located at the same physical address were classified into the same cohort. For the final analysis, 1,339 hospital-level medical institutions that satisfied the research criteria and had provided medical services continuously for five years from 2017 to 2021 were chosen.
Measurement
Outcome variable
To determine the effect of the application of the revised calculation method of the nursing fee differentiation policy on the improvement of medical institutions’ the nurse staffing ratios, this study used the nurse staffing ratio of the general ward of each medical institution in the second quarter of each year from 2017 to 2021 as an outcome variable. Based on the grading classification as part of the nursing fee differentiation policy, nurse staffing ratios of the general wards were classified according to the number of patients (number of beds before the revision) per nurse in the general wards.
Nurse staffing ratios were calculated by dividing the average number of patients (or beds) for three months from April to June each year by the average number of nurses during the same period and had values ranging from grade 1 to grade 7.
The specific criteria for each grade are shown in Table
1; using grade 6 as the reference point, the inpatient nursing fee increases by 10% to 20% of the immediately lower grade in grades 1 to 5, and decreases by 2% to 5% depending on the location of the medical institution in grade 7. Since grade 1 was the highest grade and grade 7 was the lowest grade for nurse staffing ratio, this grade was reverse-coded and analyzed for ordered logistic regression.
Other variables
Medical institutions included in the study were divided into three categories based on when the revised calculation method for the nurse staffing ratio was implemented: the first-applied group (medical institutions to which the revised calculation method was applied from 2018), second-applied group (institutions to which the revised calculation method was applied from 2020), and not applied group (medical institutions excluded from the revised calculation method). Medical institutions were divided into general hospitals and hospitals. According to Korean Medical Law, a hospital is a medical institution with at least 30 beds and is designated as a general hospital if specific criteria are satisfied, such as having more than 100 inpatient beds, establishing more than seven departments, and having a specialist in each department. The type of establishment of medical institutions was divided into public and private hospitals, and the total number of beds in medical institutions was divided into four categories: fewer than 50, 50 to 99, 100 to 199, and 200 or more. Based on the ratio of non-insurance-covered beds that are not covered by NHI, for which the patient pays 100% of the hospital bed charges, hospitals were classified into less than 5%, 5% to less than 10%, 10% to less than 15%, and 15% or more. The physician staffing level was measured as the number of physicians (including specialists) per 100 beds and divided into four categories: fewer than 5, 5 to fewer than 10, 10 to fewer than 15, and 15 or more physicians. The level of medical equipment acquisition was measured as the number of magnetic resonance imaging (MRI) devices per 100 beds (at least one, more than zero but less than one, and zero).
Data analysis
The distribution of nurse staffing ratios and the characteristics of medical institutions in the study were described using descriptive statistics, such as frequencies and percentages. The distribution and changes in nurse staffing ratios according to the characteristics of the medical institutions were analyzed using the chi-square test or Fisher's exact test. Changes in the distribution of nurse staffing ratios according to the characteristics of medical institutions during the cohort period were analyzed by comparing the nurse staffing ratios in 2017 with those in 2021. Longitudinal data analysis was performed to examine the effect of the revised calculation method for the nurse staffing ratio (treatment effect) on the overall changes in nurse staffing ratios of each medical institution from 2017 to 2021(time effect). As the outcome variable, the nurse staffing ratio is an ordinal variable ranging from 1 to 7, a multivariable generalized estimating equation model was used to conduct ordered logistic regression. Model 1 reflected only the application period of the revised nurse staffing ratio as an independent variable; Model 2 reflected the application period and year, and Model 3 reflected the application period and all control variables.
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.