National Practice Pattern and Time Trends in Treatment of Upper Urinary Tract Calculi in Korea: a Nationwide Population-Based Study

Machine learning constructs a diagnostic prediction model for calculous pyonephrosis

In order to provide decision-making support for the auxiliary diagnosis and individualized treatment of calculous pyonephrosis, the study aims to analyze the clinical features of the condition, investigate its risk factors, and develop a prediction model of the condition using machine learning techniques. A retrospective analysis was conducted on the clinical data of 268 patients with calculous renal pelvic effusion who underwent ultrasonography-guided percutaneous renal puncture and drainage in our hospital during January 2018 to December 2022. The patients were included into two groups, one for pyonephrosis and the other for hydronephrosis. At a random ratio of 7:3, the research cohort was split into training and testing data sets. Single factor analysis was utilized to examine the 43 characteristics of the hydronephrosis group and the pyonephrosis group using the T test, Spearman rank correlation test and chi-square test. Disparities in the characteristic distributions between the two groups in the training and test sets were noted. The features were filtered using the minimal absolute value shrinkage and selection operator on the training set of data. Auxiliary diagnostic prediction models were established using the following five machine learning (ML) algorithms: random forest (RF), xtreme gradient boosting (XGBoost), support vector machines (SVM), gradient boosting decision trees (GBDT) and logistic regression (LR). The area under the curve (AUC) was used to compare the performance, and the best model was chosen. The decision curve was used to evaluate the clinical practicability of the models. The models with the greatest AUC in the training dataset were RF (1.000), followed by XGBoost (0.999), GBDT (0.977), and SVM (0.971). The lowest AUC was obtained by LR (0.938). With the greatest AUC in the test dataset going to GBDT (0.967), followed by LR (0.957), XGBoost (0.950), SVM (0.939) and RF (0.924). LR, GBDT and RF models had the highest accuracy were 0.873, followed by SVM, and the lowest was XGBoost. Out of the five models, the LR model had the best sensitivity and specificity is 0.923 and 0.887. The GBDT model had the highest AUC among the five models of calculous pyonephrosis developed using the ML, followed by the LR model. The LR model was considered be the best prediction model when combined with clinical operability. As it comes to diagnosing pyonephrosis, the LR model was more credible and had better prediction accuracy than common analysis approaches. Its nomogram can be used as an additional non-invasive diagnostic technique.

Development and validation of a predictive model for treatment outcome after emergency extracorporeal shockwave lithotripsy in patients with symptomatic ureteral stones during the COVID-19 pandemic: in a large prospective cohort

The predictors of treatment outcome after emergency extracorporeal shockwave lithotripsy (SWL) are not well characterized. Therefore, based on a large prospective cohort, we aimed to develop and validate a nomogram for predicting treatment outcome after emergency SWL in patients with symptomatic ureteral stones. The development cohort included 358 patients with symptomatic ureteral stones who underwent emergency SWL between June 2020 and August 2021 in our hospital. One hundred and twenty-nine patients with symptomatic ureteral stones participated in the validation cohort from September 2021 to April 2022. The data were prospectively recorded. The backward stepwise selection was applied using the likelihood ratio test with Akaike's information criterion as the stopping rule. The efficacy of this predictive model was assessed concerning its clinical usefulness, calibration, and discrimination. Finally, 15.6% (56/358) of patients in the development cohort and 14.0% (18/129) of those in the validation cohort suffered from stone-free failure after emergency SWL. We identified four predictors for stone-free failure: stone size, stone density, skin to stone distance (SSD), and degree of hydronephrosis. This model showed good discrimination with an area under the receiver operating characteristic (AUROC) curves of 0.935 (0.899-0.971) and good calibration (P = 0.059). The decision curve analysis showed that the model was clinically valuable. In this large prospective cohort, we found that stone size, stone density, SSD, and degree of hydronephrosis were predictors of treatment outcome after emergency SWL. This nomogram will be helpful in preoperative risk stratification to provide individualized treatment recommendations for each patient. Furthermore, early identification and appropriate management of patients may increase the success rate of emergency SWL during the COVID-19 pandemic.

Predictors of successful emergency shock wave lithotripsy for acute renal colic

The role of emergency shockwave lithotripsy (SWL) in persistent pain control in patients with ureteral stones is not well established. The aim of this study is to evaluate efficacy as well as the predicting variables for successful early SWL patients with symptomatic ureteral stones. Eighty-six patients with a persistent renal colic secondary to single ureteral stone (6–12 mm) were prospectively enrolled in this study. SWL was performed within 24 h of the onset of flank pain. Pain control and stone-free rate after emergency SWL session were 58.1% and 44.2%, respectively. Seven patients required post-SWL ureteroscopy and ureteral stent placement for uncontrolled pain. The overall 3-month stone-free rate after SWL monotherapy was 83.7%. On multivariate analysis, predictors for pain relief after emergency SWL were lower Hounsfield (HU) stone density, mild hydronephrosis (HN) at presentation and presentation during the first colic episode. Lower HU stone density was the single predictor of successful stone clearance after single emergency SWL session on multivariate analysis. In conclusion, early SWL is feasible and effective in management of ureteral stones presented by renal colic with low HU.

Translation and Linguistic Validation of the Korean Version of the Wisconsin Stone Quality of Life Questionnaire

Purpose

Although cure rate and efficacy of treatment for urinary stone disease have been improved, clinicians have been indifferent to the quality of life (QoL) of stone patients in Korea. The objective of this study was to develop a Korean version of Wisconsin questionnaire about quality of life questionnaire (K-WISQOL) of stone patients for use in Korea.

Methods

Linguistic validation was permitted for translation by its developers. Three bilingual nonspecialists and 11 panels who were actively involved in treating urinary stone patients performed the translation and linguistic validations. A trained interviewer and 5 Korean patients carried out cognitive debriefing.

Results

Noun words such as “energy” and “responsibilities” were very difficult to translate to Korean. They were substituted by more comprehensive words. After backward translation, translated sentences showed a good agreement with the original WISQOL. During backward translation and the second reconciliation, previously translated Korean version was revised in 5 sentences. In the cognitive debriefing process, all 5 patients thought that these questions explained the patient’s situation well. Most of these respondents answered that explanatory notes of questionnaire were well written and the format of the questionnaire was easy to follow.

Conclusions

The present study demonstrated that, despite language differences, translation and linguistic validation of the K-WISQOL were successfully performed. This K-WISQOL could be useful tools for treatment plan and patient care.

Analysis of Patients with Urolithiasis Visiting the Emergency Department between 2014 and 2016 in Korea: Data from the National Emergency Department Information System

This study investigated the characteristics of patients with urolithiasis visiting an emergency department based on a national database system in Korea. This study spanned a period of three years from January 1, 2014 to December 31, 2016. A retrospective census was conducted using the National Emergency Department Information System for urolithiasis patients. Patient data, including age, sex, insurance type, emergency department visit date and time, discharge date and time, emergency department treatment result, visit flow, and hospitalization route, were extracted and analyzed. Overall, 103,981, 112,083, and 120,647 patients/year during the 2014-2016 study period visited an emergency department with a diagnosis related to urolithiasis. Total monthly emergency department visits ranged from 35,927 in August (highest) to 24,008 in February. Overall, 13.2% of patients were hospitalized and the hospitalization rate was stable (estimated annual percent change) over the study period. Patients aged <9 years or ≥70 years and those with medical aid had higher hospitalization rates. A higher number of visits occurred in the hot season, on weekends, and in the 6 a.m. and 8 p.m. time slots. This nationwide study revealed that the percentage of patients visiting an emergency department with urolithiasis was higher in August, in the early morning, and at weekends.

Risk factors and outcomes of urosepsis in patients with calculous pyonephrosis receiving surgical intervention: a single-center retrospective study

Background

Urosepsis is a catastrophic complication, which can easily develop into septic shock and lead to death if not diagnosed early and effectively treated in time. However, there is a lack of evidence on the risk factors and outcomes in calculous pyonephrosis patients. Therefore, this study was conducted to identify risk factors and outcomes of intra- and postoperative urosepsis in this particular population.

Methods

Clinical data of 287 patients with calculous pyonephrosis were collected. In the univariate and multivariate analysis, all patients were divided into urosepsis group and non-urosepsis group. The diagnosis of urosepsis was mainly on the basis of the criteria of American College of Chest Physicians (ACCP)/Society of Critical Care Medicine (SCCM). Patient characteristics and outcomes data were analyzed, and risk factors were assessed by binary logistic regression analysis.

Results

Of 287 patients, 41 (14.3%) acquired urosepsis. Univariate analysis showed that white blood cell (WBC > 10*10^9/L) before surgery (P = 0.027), surgery types (P = 0.009), hypotension during surgery (P < 0.001) and urgent surgery (P < 0.001) were associated with intra- and postoperative urosepsis for calculous pyonephrosis patients. In multivariate analysis, hypotension during surgery and urgent surgery were closely related to intra- and postoperative urosepsis. Outcome analysis suggested that patients developing urosepsis had a longer intensive care unit (ICU) stay and postoperative hospital stay and higher mortality.

Conclusions

Hypotension during surgery and urgent surgery were risk factors of intra- and postoperative urosepsis for calculous pyonephrosis patients, which may lead to a prolonged ICU stay, postoperative hospital stay and higher mortality.

Study on the prevalence and incidence of urolithiasis in Korea over the last 10 years: An analysis of National Health Insurance Data

Purpose

We aimed to analyze the incidence and prevalence of urolithiasis in Korea over the last decade using the National Health Insurance (NHI) sample cohort data.

Materials and Methods

From January 2002 to December 2013, we enrolled sample cohort data from the NHI. Patients diagnosed with international classification of diseases code N20 or N13.2 were included. The incidence and prevalence rate was counted from the same period and patients previously diagnosed with urolithiasis were excluded. We compared the incidence and prevalence of urolithiasis by region, age, and sex, and identified the changes.

Results

Total 1,111,828 subjects were included. Of these subjects, 36,857 had urolithiasis. The male-to-female ratio was 1.57:1, and total incidence rate was 3.27 per 1,000 person-years (1,000p-yrs). The annual incidence was lowest in 2013 (3,138 patients) and highest in 2005 (3,751 patients). Incidence rate by diagnostic code was highest in ureter stone only (2.49 per 1,000p-yrs) and was lowest in kidney and ureter stone both (0.17 per 1,000p-yrs). Prevalence gradually increased from 3,172 in 2002 and 5,758 in 2013. Jeollanam-do had the highest incidence rate of 3.70 persons per 1,000p-yrs, and Jeju had the lowest rate of 2.84 persons per 1,000p-yrs. In gender analysis, Daegu had the highest incidence (4.56) in males, Jeollanam-do had the highest incidence (3.20) in females.

Conclusions

Annual incidence remained stable, whereas prevalence gradually increased. The incidence in male was 1.57 times higher than female, and the peak incidence age was 45–49 years, with the highest incidence occurring in Jeollanam-do and the lowest in Jeju.

Chronological Trends in Clinical and Urinary Metabolic Features over 20 Years in Korean Urolithiasis Patients

Urolithiasis is common and is becoming more prevalent worldwide. This study assessed the chronological trends in clinical and urinary metabolic features over 20 years in Korean urolithiasis patients. We performed a retrospective analysis of 4,076 patients treated at our clinic from 1996 to 2015. Urinary metabolic data and stone analysis data were available for 1,421 and 723 patients (34.9% and 17.7%), respectively. Patients were categorized into 4 groups according to the date of initial diagnosis: group 1 (1996-2000, n = 897), group 2 (2001-2005, n = 1,018), group 3 (2006-2010, n = 1,043), and group 4 (2011-2015, n = 1,118). Incidental detection of uric acid renal stones has become more prevalent in the past 10 years, accompanied by an increase in body mass index and age at diagnosis. Similarly, the prevalence of diabetes mellitus and of hypertension increased from one group to the next throughout the study period. Levels of 24-hour urinary excretion of sodium, calcium, uric acid, and oxalate have decreased significantly over the study period. The incidence of urinary metabolic abnormalities also showed an identical tendency. The proportion of stones composed of uric acid increased over the study period. In conclusion, incidental detection of uric acid renal stones has become more prevalent in Korea in the past 20 years. Urinary excretion of lithogenic constituents and the incidence of urinary metabolic abnormalities have decreased significantly over this period.