The effect of diagnosis-related group payment system on the quality of medical care for pelvic organ prolapse in Korean tertiary hospitals

Our study has several limitations. First, the claim data of only 43 tertiary hospitals were examined, which does not represent the whole nation. In general, patients who are older and have more medical comorbidities or a more severe degree of POP are referred to tertiary hospitals. These patients’ characteristics may affect the results. Second, because the current study included the data on the patients who underwent hysterectomy, all changes in the clinical practice for POP since the introduction of the DRG system could not be assessed. The present study indicates that under the DRG system, health care providers may be reluctant to perform the operations for patients who require greater effort in medical care, as the patients undergoing operations after the introduction of DRG system had fewer medical comorbidities. Otherwise, the physicians may change their practice patterns for POP to operations that are not required to use the DRG payment system such as robot-assisted operations, which may result in an increase in health care expenditures. Third, the reoperation and pessary insertion rates as the retreatment outcomes for POP and stress urinary incontinence were assessed. Unfortunately, information on various non-surgical treatment options other than pessary insertion was not available using the National Health Insurance claim data. In addition, the follow-up duration was one year, which may not be long enough to evaluate reoperation rates considering the patients’ preference for non-surgical treatment options over reoperation. Despite several limitations, the current study has many strengths. First, National Health Insurance claim data that included a large sample of patients and hospitals were used. Second, as of the time of writing, this is the first study to evaluate the effect of the introduction of DRG system on the quality of care for POP. Third, our results highlight the problems caused by the uniform application of the DRG system. To enhance the efficacy of DRG-based payments, it is essential to determine sufficiently homogenous groups of patients based on treatment cost. In contrast with hysterectomies for other benign indications, most of POP surgeries are performed for older women who incur significantly higher medical costs by requiring greater medical attention and having more comorbid conditions. In addition, hysterectomy is only one of the procedures used to treat POP, with additional procedures recommended for complete correction of POP. Therefore, the current Korean DRG system for hysterectomy needs to be reformed to provide sufficient medical care to the POP patients.

Since its introduction in 1977, the National Health Insurance Program in Korea has paid health care providers on a fee-for-service basis. The fee-for-service reimbursement system has led to the rapid growth of health expenditures and changes in medical care such as the substitution of more profitable and less regulated services. To address these problems, the government adopted a pilot program utilizing diagnosis-related group (DRG) reimbursement for inpatient care in 1997. In 2002, this payment system was applied to seven disease groups (lens operation, tonsillectomy/adenoidectomy, appendectomy, inguinal/femoral hernia operation, hemorrhoidectomy, uterine/adnexa operation, cesarean delivery) through voluntary participation of health care institutions [ 1 ]. The DRG system became mandatory in hospitals and clinics on July 1, 2012, and was applied to general and tertiary hospitals on July 1, 2013. Because DRG provides a fixed reimbursement for inpatient services, it encourages health care providers to reduce the length of stay or the intensity of services, which could influence the quality of care for patients. In spite of these concerns, several studies have reported that the Korean DRG system is effective in containing medical expenses with little negative impact on quality of care [ 1 – 3 ]. Further, it has also been reported that the implementation of the DRG-based payment system in the field of obstetrics and gynecology, specifically with regard to cesarean section, hysterectomy, and adnexectomy, in Korean tertiary hospitals led to reductions in the length of stay without increasing outpatient visits and readmission. Decreases in the rates of concomitant colpopexy and midurethral slings at the time of hysterectomy were also reported after introduction of the DRG [ 4 ]. Pelvic organ prolapse is the descent of one or more aspects of the vagina and uterus, including the anterior vaginal wall, posterior vaginal wall, uterus, or vaginal vault. Even though hysterectomy has historically been performed to treat uterine prolapse, hysterectomy alone is not adequate, and concomitant colpopexy should be performed to reduce the risk of recurrent POP [ 5 – 7 ]. Patients with POP are also at risk for postoperative stress urinary incontinence. POP and stress urinary incontinence coexist in up to 80% of patients [ 8 ], and stress urinary incontinence can occur after POP surgery even in patients without previous symptoms as a result of the correction of anatomical urethral kinking from advanced prolapse [ 9 ]. Therefore, a concomitant anti-incontinence surgery is often required to prevent postoperative stress urinary incontinence. Taken together, the decrease in the rates of concomitant procedures at the time of hysterectomy after introduction of the DRG may have an adverse effect on the quality of care for patients with POP. In the current study, data were collected on the patients who underwent hysterectomy for POP with the extension of study period. Changes in clinical practice patterns after implementing the DRG-based payment system and its effect on the quality of care for POP were assessed.

A total of 7362 patients were identified for inclusion in this study, with 3912 who underwent hysterectomy for POP before and 3450 who underwent hysterectomy for POP after the introduction of the DRG payment system. This represents a decrease of 11.8% in the total number of surgeries after the introduction of DRG. The patient group that underwent the operations after the introduction of the DRG system was significantly older but had fewer medical comorbidities such as diabetes and hypertension than the patient group undergoing surgery before the introduction of the DRG. There was no significant difference in the income level of the two groups ( Table 2 ). Values are presented as mean ± standard deviation or n (%). DRG, diagnosis-related group. *Statistically significant After the introduction of the DRG system, the average length of stay significantly decreased (7.74 ± 2.88 to 6.63 ± 2.18 days, p<0.001). With regard to concomitant procedures, the rates of colpopexy and midurethral slings significantly decreased (8.13% and 10.71% to 5.04% and 3.77%, respectively, all p<0.001), while colporrhaphy rates slightly increased ( Table 3 ). The decline in the rates of concomitant colpopexy and midurethral sling procedures did not change significantly in 2015, when a portion of operation fee for these procedures became reimbursable (the rates of colpopexy and midurethral sling in 2015 were 3.79% and 3.58%, respectively; all p<0.001 compared to those before the introduction of DRG system). Values are presented as mean ± standard deviation or n (%). DRG, diagnosis-related group. *Statistically significant The number of postsurgical outpatient visits significantly increased after the introduction of the DRG system (2.78±2.33 to 2.98±2.47, p<0.001) though readmission rates did not change. There was no difference in the reoperation rates for POP and stress urinary incontinence before and after introduction of the DRG. However, pessary insertion rates significantly increased after introduction of the DRG (0.10% to 0.38%, p = 0.015) ( Table 4 ). Values are presented as mean ± standard deviation or n (%). DRG, diagnosis-related group; POP, pelvic organ prolapse; SUI, stress urinary incontinence. * Statistically significant

The implementation of DRG for hysterectomy in Korean tertiary hospitals has led to increase of outpatient visits and reduced surgical management of POP. Specifically, the rates of concomitant colpopexy and midurethral slings requiring a specialized skill or the use of an expensive material significantly decreased. Although these changes did not increase the rates of reoperation for recurrence POP and stress urinary incontinence within the first postoperative year, a further study will be required to evaluate the long-term outcomes.

The present study was a retrospective observational cohort study that included 43 tertiary hospitals in Korea that adopted the DRG-based payment system on July 1, 2013. Hospitals included in this study can be found in S1 Table . National Health Insurance claim data collected from January 2011 to December 2016 were utilized. Patients included were those who were admitted to these hospitals from January 2011 to December 2015 to undergo hysterectomy for POP. Participants were identified by the Korea Classification of Diseases, 6th Edition diagnostic codes and Electronic Data Interchange procedure codes ( Table 1 ). The study proposal was reviewed and approved by the institutional review board of National Health Insurance Service Ilsan Hospital in 2017 (NHIMC 2017-12-002-001). KCD, Korea Classification of Diseases; EDI, Electronic Data Interchange To examine the effects of the DRG system on the quality of care for POP, several variables were evaluated including length of stay, concomitant procedures, subsequent outpatient visits, readmission, and retreatment for POP or stress urinary incontinence. Owing to limitations of the data, the only clinical characteristics of patients were age, economic status, and diagnosis of diabetes mellitus and/or hypertension. Length of stay was measured using admission and discharge dates. The numbers of outpatient visits and readmission rates within 30 days after discharge from the hospital were assessed. Rates of concomitant procedures and retreatment for POP or stress urinary incontinence within the first postoperative year were also examined. Electronic Data Interchange codes corresponding to colporrhaphy, colpopexy, pessary insertion, and midurethral slings were used for the analysis ( Table 1 ). The distribution of each categorical variable was examined using an analysis of frequencies and percentages, and chi-square tests were performed to examine the association between variables and the DRG payment system. Two-sample t-tests were performed to compare the average value and standard deviation for continuous variables. All statistical analyses were performed using SAS version 9.4 (SAS Institute, Inc.; Cary, NC, USA). A p-value of <0.05 was considered statistically significant.

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