Defining 24-hour urine parameters and kidney stone risk of student athletes.

PURPOSE: Dehydration is a risk factor for kidney stone formation. Studying populations that may experience dehydration without a known increased incidence of stone formation may help understand stone formation and prevention. High-caliber athletes represent such a population. We characterized the urinary environment of high-caliber athletes utilizing 24-hour urine collections with comparison to non-athlete controls. MATERIALS AND METHODS: After Institutional Review Board (IRB) and National Collegiate Athletic Association (NCAA) compliance officer approval, 74 college-student athletes and 20 non-athletes were enrolled. Demographics, medical history, and sport of participation were recorded. Participants were asked to provide 24-hour urine collections as well as diet and activity logs at the time of urine collection. Standard stone risk parameters were assessed and compared to litholink reference standards. RESULTS: 34 athletes and 10 non-athletes provided at least one 24-hour urine specimen for evaluation. Athletes had a high prevalence of urinary risks for stone formation including low volume (median 1.46 L), low citrate, high sodium, high calcium (females), and high uric acid (males). However, athletes also had a high prevalence of known stone-protective factors such as high urine magnesium. Athletes had a lower urine pH but high supersaturation of uric acid and calcium oxalate compared to non-athletes. CONCLUSION: Student athletes appear to have a high prevalence of urinary risk factors for stone formation such as dehydration, high calcium, high uric acid, high sodium, and low citrate. Overall stone risk in this population may be offset by increased levels of stone-protective factors such as magnesium. Further study of this population may help generate hypotheses for effective stone prevention strategies in the general population.

Estimating the health-related quality of life of kidney stone patients: initial results from the Wisconsin Stone Quality of Life Machine-Learning Algorithm (WISQOL-MLA).

OBJECTIVE: To build the Wisconsin Stone Quality of Life Machine-Learning Algorithm (WISQOL-MLA) to predict urolithiasis patients' health-related quality of life (HRQoL) based on demographic, symptomatic and clinical data collected for the validation of the Wisconsin Stone Quality-of-Life (WISQOL) questionnaire, an HRQoL measurement tool designed specifically for patients with kidney stones. MATERIAL AND METHODS: We used data from 3206 stone patients from 16 centres. We used gradient-boosting and deep-learning models to predict HRQoL scores. We also stratified HRQoL scores by quintile. The dataset was split using a standard 70%/10%/20% training/validation/testing ratio. Regression performance was evaluated using Pearson's correlation. Classification was evaluated with an area under the receiver-operating characteristic curve (AUROC). RESULTS: Gradient boosting obtained a test correlation of 0.62. Deep learning obtained a correlation of 0.59. Multivariate regression achieved a correlation of 0.44. Quintile stratification of all patients in the WISQOL dataset obtained an average test AUROC of 0.70 for the five classes. The model performed best in identifying the lowest (0.79) and highest quintiles (0.83) of HRQoL. Feature importance analysis showed that the model weighs in clinically relevant factors to estimate HRQoL, such as symptomatic status, body mass index and age. CONCLUSIONS: Harnessing the power of the WISQOL questionnaire, our initial results indicate that the WISQOL-MLA can adequately predict a stone patient's HRQoL from readily available clinical information. The algorithm adequately relies on relevant clinical factors to make its HRQoL predictions. Future improvements to the model are needed for direct clinical applications.

Association of Patient Age and Gender with Kidney Stone Related Quality of Life.

PURPOSE: Kidney stone formers have lower health related quality of life than nonstone formers. The North American Stone Quality of Life Consortium is a multicenter, longitudinal, prospective study of health related quality of life in patients with kidney stones using the WISQOL (Wisconsin Stone Quality of Life Questionnaire) with data on 2,052 patients from a total of 11 centers. This study is a subanalysis of cross-sectional data looking at the association of age, gender and race on health related quality of life of stone formers. MATERIALS AND METHODS: We performed multivariable analyses of ordinal logistic regression analyses to determine the impact of age, gender and race on health related quality of life, adjusting for other baseline covariates. The proportional odds assumption of ordinal logistic regression was checked. Total score and scores on 4 subdomains (social functioning, emotional functioning, stone related impact and vitality) were included. RESULTS: Median total score for all patients was 80.4. On multivariable analysis older patients had a significantly higher total health related quality of life score than younger patients (per 10-year increase OR 1.25, p <0.0001). Male patients had higher scores than females (OR 1.56, p = 0.0003) and nonCaucasian patients had lower health related quality of life than nonLatino Caucasian patients (OR 0.63, p = 0.0045). CONCLUSIONS: Younger and female patients with kidney stones have lower health related quality of life than older and male patients, respectively. NonCaucasian patients with stones also have lower health related quality of life. The clinical impact of these findings might include future implications for patient counseling, including dietary and medical management of stone disease, and potential changes to the paradigm of the surgical management of stones.

Low Income and Nonwhite Race are Strongly Associated with Worse Quality of Life in Patients with Nephrolithiasis.

PURPOSE: Kidney stones are a source of significant morbidity which have been shown to negatively impact health related quality of life. We sought to understand the association between health related quality of life, socioeconomic status and race among patients with kidney stones. MATERIALS AND METHODS: Patients with stones at a total of 11 stone centers across the United States completed the WISQOL (Wisconsin Stone Quality of Life questionnaire). The patient ZIP Code™ was used to estimate household income. A mixed effects regression model was constructed for analysis with ZIP Code as the random intercept. RESULTS: A total of 2,057 stone formers completed the WISQOL. Lower income was independently associated with significantly lower health related quality of life (ß = 0.372, p = 0.014), as were nonwhite race (ß = -0.299, p = 0.001), unemployed work status (ß = -0.291, p = 0.008), female gender (ß = -0.204, p <0.001), body mass index greater than 40 kg/m2 (ß = -0.380, p <0.001), 5 or more medical comorbidities (ß = -0.354, p = 0.001), severe recurrent stone formation (ß = -0.146, p = 0.045), enrollment at an acute care visit, or a preoperative or postoperative appointment (ß = -0.548, p <0.001) and recent stone symptoms (ß = -0.892, p <0.001). CONCLUSIONS: Lower income, nonwhite race and unemployed work status were independently associated with lower health related quality of life among patients with kidney stones. While clinical characteristics such as body mass and stone disease severity were also associated with health related quality of life, this study shows that socioeconomic factors are similarly important. Further research to understand the specific mechanisms by which socioeconomic status and race impact health may lend insight into methods to optimize clinical treatment of stone formers and patients with other chronic diseases.

Trends in renal calculus composition and 24-hour urine analyses in patients with neurologically derived musculoskeletal deficiencies.

PURPOSE: To better characterize metabolic stone risk in patients with neurologically derived musculoskeletal deficiencies (NDMD) by determining how patient characteristics relate to renal calculus composition and 24-hour urine parameters. MATERIALS AND METHODS: We performed a retrospective cohort study of adult patients with neurologically derived musculoskeletal deficiencies presenting to our multidisciplinary Kidney Stone Clinic. Patients with a diagnosis of NDMD, at least one 24-hour urine collection, and one chemical stone analysis were included in the analysis. Calculi were classified as primarily metabolic or elevated pH. We assessed in clinical factors, demographics, and urine metabolites for differences between patients who formed primarily metabolic or elevated pH stones. RESULTS: Over a 16-year period, 100 patients with NDMD and nephrolithiasis were identified and 41 met inclusion criteria. Thirty percent (12 / 41) of patients had purely metabolic calculi. Patients with metabolic calculi were significantly more likely to be obese (median body mass index 30.3kg / m2 versus 25.9kg / m2), void spontaneously (75% vs. 6.9%), and have low urine volumes (100% vs. 69%). Patients who formed elevated pH stones were more likely to have positive preoperative urine cultures with urease splitting organisms (58.6% vs. 16.7%) and be hyperoxaluric and hypocitraturic on 24-hour urine analysis (37mg / day and 265mg / day versus 29mg / day and 523mg / day). CONCLUSIONS: Among patients with NDMD, metabolic factors may play a more significant role in renal calculus formation than previously believed. There is still a high incidence of carbonate apatite calculi, which could be attributed to bacteriuria. However, obesity, low urine volumes, hypocitraturia, and hyperoxaluria suggest an underrecognized metabolic contribution to stone formation in this population.

The Effect of Thiazide and Potassium Citrate Use on the Health Related Quality of Life of Patients with Urolithiasis.

PURPOSE: To our knowledge it is unknown whether the benefits of medical management of urolithiasis outweigh the potential side effects of the medications used, including potassium citrate and thiazide diuretics. Therefore, we evaluated the relationship between potassium citrate or thiazides and overall stone related health related quality of life. MATERIALS AND METHODS: Cross-sectional data were obtained on stone forming enrollees in the North American Stone Quality of Life Consortium. We used the WISQOL (Wisconsin Stone Quality of Life) questionnaire to compare health related quality of life between patients treated and not treated with potassium citrate or thiazide type diuretics. Additionally, the likelihood of gastrointestinal complaints was compared between those prescribed and not prescribed potassium citrate. The likelihood of fatigue and sexual complaints was also compared in those prescribed and not prescribed thiazides. RESULTS: Of the 1,511 subjects, including 787 males and 724 females, 279 were on potassium citrate and 238 were on thiazides at study enrollment. Patients prescribed potassium citrate had higher health related quality of life in each domain vs those not prescribed potassium citrate (p <0.001). Patients prescribed thiazides had higher health related quality of life in each domain compared to those not prescribed thiazide (all p <0.01). Those prescribed potassium citrate were less likely than those not prescribed potassium citrate to report nausea, stomach upset or cramps (OR 0.57, p <0.001). Patients prescribed thiazides were less likely than those not prescribed thiazides to report fatigue (OR 0.63, p = 0.004) or reduced sexual interest and/or activity (OR 0.64, p = 0.005). CONCLUSIONS: Among stone formers the use of potassium citrate and thiazides was associated with better health related quality of life across all WISQOL domains without an increased likelihood of gastrointestinal complaints and fatigue or sexual complaints, respectively. These findings may be useful when counseling patients regarding the initiation of potassium citrate or thiazides for medical management of nephrolithiasis.

Identifying and managing the risks of medical ionizing radiation in endourology.

INTRODUCTION: The risks of exposure to medical ionizing radiation is of increasing concern both among medical professionals and the general public. Patients with nephrolithiasis are exposed to high levels of ionizing radiation through both diagnostic and therapeutic modalities. Endourologists who perform a high-volume of fluoroscopy guided procedures are also exposed to significant quantities of ionizing radiation. The combination of judicious use of radiation-based imaging modalities, application of new imaging techniques such as ultra-low dose computed tomography (CT) scan, and modifying use of current technology such as increasing ultrasound and pulsed fluoroscopy utilization offers the possibility of significantly reducing radiation exposure. We present a review of the literature regarding the risks of medical ionizing radiation to patients and surgeons as it pertains to the field of endourology and interventions that can be performed to limit this exposure. MATERIALS AND METHODS: A review of the current state of the literature was performed using MEDLINE and PubMed. Interventions designed to limit patient and surgeon radiation exposure were identified and analyzed. Summaries of the data were compiled and synthesized in the body of the text. RESULTS: While no level 1 evidence exists demonstrating the risk of secondary malignancy with radiation exposure, the preponderance of evidence suggests a dose and age dependent increase in malignancy risk from ionizing radiation. Patients with nephrolithiasis were exposed to an average effective dose of 37mSv over a 2 year period. Multiple evidence-based interventions to limit patient and surgeon radiation exposure and associated risk were identified. CONCLUSION: Current evidence suggest an age and dose dependent risk of secondary malignancy from ionizing radiation. Urologists must act in accordance with ALARA principles to safely manage nephrolithiasis while minimizing radiation exposure.

Vitamin D Repletion in Kidney Stone Formers: A Randomized Controlled Trial.

PURPOSE: Vitamin D deficiency is often detected during metabolic evaluation in the nephrolithiasis population. Multiple vitamin D repletion protocols exist, although their differing impact on urinary stone formation risk factors is unclear. MATERIALS AND METHODS: Patients with a history of calcium stones and vitamin D deficiency (less than 30 ng/ml) were randomized to receive either 1,000 IU daily or 50,000 IU weekly of vitamin D supplementation for 6 weeks. Patients completed a pretreatment and posttreatment serum vitamin D level evaluation and 24-hour urine collections to assess the response and any changes in urine stone formation risk parameters. RESULTS: A total of 21 patients completed the study, including 8 who received 1,000 IU daily and 13 who received 50,000 IU weekly. The 50,000 IU weekly group showed a significant increase in median serum vitamin D levels of 23 ng/ml (135%, p <0.01), while the 1,000 IU daily group showed a nonsignificant median increase of 9 ng/ml (49%, p = 0.12). Post-repletion 24-hour urine analysis demonstrated no significant change in urine calcium between the groups, including a median change of -11 mg (IQR -143-29) in patients receiving 1,000 IU and -16 mg (IQR -42-66) in those receiving 50,000 IU. Between the groups there was no significant difference in the supersaturation of calcium oxalate or calcium phosphate. CONCLUSIONS: High dose and low dose vitamin D repletion had no effect on urine calcium excretion or the supersaturation of calcium salts in known stone formers. The higher dosing regimen, which had superior repletion, may be the optimal protocol in patients with vitamin D deficiency.

Validation and Reliability of the Wisconsin Stone Quality of Life Questionnaire.

PURPOSE: WISQOL (Wisconsin Stone Quality of Life questionnaire) is a disease specific, health related quality of life measure designed for patients who form kidney stones. The purpose of this study was to demonstrate the external and convergent validity of WISQOL and assess its psychometric properties. MATERIALS AND METHODS: At the WISQOL creation site (development sample) and at 8 geographically diverse centers in the United States and Canada (consortium sample) patients with a history of kidney stones were recruited. Item response option variability, correlation patterns and internal consistency were compared between samples. Convergent validity was assessed by patients who completed both WISQOL and SF-36v2® (36-Item Short Form Health Survey, version 2). RESULTS: Results were analyzed in 1,609 patients, including 275 in the development sample and 1,334 in the consortium sample. Response option variability patterns of all items were acceptable. Internal WISQOL consistency was acceptable. Intersample score comparisons revealed few differences. For both samples the domain-total WISQOL score correlations exceeded 0.86. Item level analyses demonstrated suitable variation, allowing for discriminatory scoring. At the time that they completed WISQOL, patients with stones and stone related symptoms scored lowest for health related quality of life. Patients with stones but no symptoms and those with no stones scored higher. The convergent validity substudy confirmed the ability of WISQOL to identify stone specific decrements in health related quality of life that were not identified on SF-36v2. CONCLUSIONS: WISQOL is internally consistent and discriminates among patients with different stone statuses and symptoms. WISQOL is externally valid across the North American population. It may be used for multicenter health related quality of life studies in kidney stone disease.

Survey of Applicant Experience and Cost in the Urology Match: Opportunities for Reform.

PURPOSE: The urology match is highly competitive but there is a paucity of published data regarding the costs and barriers that applicants face. We gathered data on contributors to cost in the 2014 urology residency match. MATERIALS AND METHODS: A survey was sent to all applicants offered an interview at each of 18 participating institutions. Information on demographics, interview related costs, access to financial aid, frequency of away rotations and second look invitations was collected. RESULTS: A total of 173 respondents spent a median of $7,000 on the urology match. Applicants attended a mean of 14 interviews with an average per interview cost of $500. Overall 95% of respondents did at least 1 away rotation and 79% reported being asked to return for a second look interview at least once. Of the respondents 66% did not receive any financial aid for interviews and only 28% believed their financial aid departments provided adequate financial planning. Of those surveyed 20% indicated that their financial situation limited the number of interviews they attended. CONCLUSIONS: We estimate that $3,122,000 was spent by applicants on the 2014 urology match. One in 5 applicants reported limiting the number of interviews they attended due to financial concerns. Adequate financial planning resources were not widely available. Nearly all applicants went on an away rotation and encouragement to return for second look interviews was common. These factors may contribute to financial and regional bias in the match process, and are potential targets for reform.

The prone ureteroscopic technique for managing large stone burdens.

Percutaneous nephrolithotomy (PCNL) is the standard treatment for patients with large stone burdens, but can be associated with significant complications. Flexible ureteroscopy is an alternative approach that is less invasive, but often requires multiple procedures. Typically, many factors play a role in the decision to perform PCNL or ureteroscopy. The challenge is that it is difficult to predict which stone burdens will be able to be cleared ureteroscopically. We describe our approach using initial prone ureteroscopy with the transition to standard prone PCNL if required.

Use of social media in urology: data from the American Urological Association (AUA).

OBJECTIVE: To characterise the use of social media among members of the American Urological Association (AUA), as the use of social media in medicine has greatly expanded in recent years. SUBJECTS AND METHODS: In December 2012 to January 2013, the AUA e-mailed a survey with 34 questions on social media use to 2000 randomly selected urologists and 2047 resident/fellow members. Additional data was collected from Symplur analytics on social media use surrounding the AUA Annual Meeting in May 2013. RESULTS: In all, 382 (9.4%) surveys were completed, indicating 74% of responders had an online social media account. The most commonly used social media platforms were Facebook (93%), followed in descending order by LinkedIn (46%), Twitter (36%) and Google+ (26%). Being aged <40 years was an important predictor of social media use (83% vs 56%), with greater uptake among residents/fellows compared with attendings (86% vs 66%). Only 28% of respondents used social media partly or entirely for professional purposes. During the 2013 AUA Annual Meeting, there were >5000 tweets from >600 distinct contributors. CONCLUSION: As of early 2013, among respondents to an e-mail survey, most urologists and urology trainees used some form of social media, and its use in urology conferences has greatly expanded.

Patient Safety and Quality Improvement in Minimally Invasive Surgery.

Background: The journey of minimally invasive (MI) urology is one of quality improvement (QI) and patient safety. New techniques have been progressively studied for adoption and growth. As more advanced methods of data collection and analysis are developed, a review of the patterns and history of these principles in the development of MI urology can inform future urologic QI and patient safety initiatives. Objective: To perform a scoping review identifying patterns of QI and patient safety in MI urology. Methods: PubMed and the American Urological Association (AUA) journal search page were screened on December 2022 for publications using the search parameters "quality improvement" and "minimally invasive." Articles were screened according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews (PRISMA-ScR). Results: The initial literature search identified 471 articles from PubMed and 57 from the AUA journal search page. After screening, 528 articles were relevant to the topic and reviewed. Four hundred eighty-two articles were duplicates or did not meet inclusion criteria. Forty-six are included in this review. Conclusion: Urology has developed a pattern of assessing MI surgery vs the open counterpart. This includes analyzing the newest approach to understand complications, examining the factors contributing to complications, and lastly designing projects to mitigate future risk. This information, as well as advanced methods of data collection, has identified areas of improvement for new QI projects. The stage is set for a promising future with the adoption of advanced QI in daily urologic practice to improve patient safety and minimize errors.

Who Are the Mentors of the Future Endourologist? An Analysis of Endourological Society Program Directors.

Introduction: Surgical training programs are pivotal in shaping skilled and compassionate surgeons, with mentors playing a crucial role in instilling clinical competence and essential attributes. This study aims to describe the characteristics of the program directors of Endourological Society-accredited fellowship programs. Methodology: The Endourological Society's website was used to identify program directors. The following data points were extracted: year of graduation from medical school, year of completing residency, if they had attended fellowship training or held additional degrees such as (PhD, MS, MBA, MSc, etc.), and number of publications on Scopus. Descriptive statistics were used to analyze the data. Results: A total of 84 fellowship programs and 115 program directors were identified. Geographically, 77.4% (n = 65) were in North America, 8.3% (n = 7) in Asia, 8.3% (n = 7) in the Middle East, 3.6% (n = 3) in Europe, and 2.4% (n = 2) in South America. Of the 115 program directors, 94.8% were male, and only 5.2% were female. Program directors graduated medical school with a median year of 1998 (1966-2015). Eighty percent attended fellowship programs, and 19.1% held additional degrees (PhD, MS, MBA, MSc, etc.). The median number of publications was 79 (4-1963), with a median citation of 1607 (1-43,565). The median H-index was 23 (range: 1-110). Conclusion: Most program directors of Endourological Society-accredited fellowship programs are fellowship-trained and a notable number held a second degree. However, a pronounced gender disparity is observed, with limited female representation among program directors. This assessment contributes valuable insights into the urology and endourology mentorship, emphasizing the need for broader diversity and inclusivity in leadership roles.

External validation of a nomogram for outcome prediction in management of medium-sized (1-2 cm) kidney stones.

BACKGROUND: Stone nomogram by Micali et al., able topredict treatment failure of shock-wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) in the management of single 1-2 cm renal stones, was developed on 2605 patients and showed a high predictive accuracy, with an area under ROC curve of 0.793 at internal validation. The aim of the present study is to externally validate the model to assess whether it displayed a satisfactory predictive performance if applied to different populations. METHODS: External validation was retrospectively performed on 3025 patients who underwent an active stone treatment from December 2010 to June 2021 in 26 centers from four countries (Italy, USA, Spain, Argentina). Collected variables included: age, gender, previous renal surgery, preoperative urine culture, hydronephrosis, stone side, site, density, skin-to-stone distance. Treatment failure was the defined outcome (residual fragments >4 mm at three months CT-scan). RESULTS: Model discrimination in external validation datasets showed an area under ROC curve of 0.66 (95% 0.59-0.68) with adequate calibration. The retrospective fashion of the study and the lack of generalizability of the tool towards populations from Asia, Africa or Oceania represent limitations of the current analysis. CONCLUSIONS: According to the current findings, Micali's nomogram can be used for treatment prediction after SWL, RIRS and PNL; however, a lower discrimination performance than the one at internal validation should be acknowledged, reflecting geographical, temporal and domain limitation of external validation studies. Further prospective evaluation is required to refine and improve the nomogram findings and to validate its clinical value.

A nephrolithometric nomogram to predict treatment success of percutaneous nephrolithotomy.

PURPOSE: Imaging is routinely done preoperatively and postoperatively to assess patients treated with percutaneous nephrolithotomy. We developed a nomogram for percutaneous nephrolithotomy success. MATERIALS AND METHODS: From November 2007 to December 2009 the CROES (Clinical Research Office of the Endourological Society) collected data on consecutive patients at 96 centers globally. Patients were evaluated for stone-free status using plain x-ray of the kidneys, ureters and bladder. Treatment success was defined as no visible stones or residual fragments less than 4 mm. Multivariate regression was used to model the relationship between preoperative descriptors and the stone-free rate. Variables included case load, prior treatment, body mass index, staghorn stones, renal anomalies, and stone burden, location and count. Bootstrapping techniques were used to validate the model. Adjusted chi-square statistic values were used to rank the prognostic value of variables. A nomogram was developed using significant predictors from the model. We assessed the predictive accuracy of the nomogram using the ROC curve AUC. The nomogram was calibrated. RESULTS: Stone burden was the best predictor of the stone-free rate (chi-square = 30.27, p <0.001). Other factors associated with the stone-free rate were case volume (chi-square = 35.75, p <0.001), prior stone treatment (chi-square = 14.55, p <0.012), staghorn stone (adjusted chi-square = 4.73, p <0.029), stone location (chi-square = 14.74, p <0.001) and stone count (chi-square = 4.78, p <0.004). A nephrolithometric nomogram was developed with predictive accuracy (AUC 0.76). CONCLUSIONS: The percutaneous nephrolithotomy stone-free rate can be predicted using preclinical data and radiological information. We present a nephrolithometric nomogram for percutaneous nephrolithotomy.

The Endourological Society Inaugural Census Report.

The Endourological Society, the premier urologic society encompassing endourology, robotics, and focal surgery, is composed of a diverse group of >1300 urologists. However, limited information has been collected about society members. Recognizing this need, a survey was initiated to capture data regarding current member practices, as well as help the Society shape the future direction of the organization. Presented herein is the inaugural Endourological Society census report as the beginning of a continued effort for global improvement in the field of endourology. Using a REDCap® database, an email survey was circulated to the membership of the Endourological Society from May through June 2021. Twenty questions were posed, categorizing member data in terms of epidemiology/demographics, practice patterns, member opinions, and future educational preferences. Responses were received from 534 members, representing 40.3% of membership. Data demonstrated that the average age, gender, race, and ethnicity of the typical Society member respondent is a 48-year-old Caucasian male working in the United States, with a mean of 25 years in practice. Retrograde endoscopy and percutaneous nephrolithotomy were identified as the most common practice skills, and 50% of members are involved in robotics. Importantly, the census confirmed that the World Congress of Endourology and Technology remains popular with Society members as a means of educational advancement. To sustain and advance the Society, information is required to understand the career interests and future educational desires of its members. This inaugural census provides crucial data regarding its membership and how the Society can achieve continued success and adjust its focus. Future census efforts will expand on the initial findings and stratify the data to elucidate changes in the needs of the Society as a whole. Circulating an annual census will allow for continued improvements in the field of endourology and, ultimately, better care for urologic patients.

The Impact of Bilateral Stone Disease on Patients' Disease Progression and Health-Related Quality of Life.

Purpose: Patients with recurring kidney stone events can expect significant morbidity and functional impairment. Few studies have evaluated the effect of bilateral kidney stones on disease progression and quality of life. We wanted to determine the association of bilateral stone disease on age of onset, and the impact on number of stone events and individual kidney stone disease-specific health-related quality of life (HRQOL) by analyzing the validated and prospectively collected Wisconsin Stone Quality of Life (WISQOL) database. Materials and Methods: We studied 2906 stone patients from 16 centers in North America after having completed the WISQOL questionnaire from 2014 to 2019. Kidney stone formers were assessed if kidney stones were bilateral or unilateral on imaging. Analysis with a chi-square test compared categorical variables. Bilateral kidney stone disease and its impact on HRQOL were evaluated through a multivariable linear regression model. Results: Of 2906 kidney stone formers, 1340 had unilateral kidney stones and 1566 had bilateral kidney stones. We observed more frequently that patients with bilateral stones had an increased number of depression/anxiety symptoms, renal tubular acidosis, and rheumatoid arthritis (all p < 0.05). Patients with bilateral stones had a younger mean (standard deviation [SD]) age of kidney stone disease onset (37.2 ± 15.8 vs 46.4 ± 15.9 years of age, p < 0.001). Bilateral kidney stone formers had a higher mean (SD) number of stone events (11.3 ± 21.8) than unilateral kidney stone formers (3.0 ± 5.1) (p < 0.001). Within our multivariable analysis, we found that HRQOL was negatively affected by the presence of bilateral stones for kidney stone patients (ß = -11.2 [confidence interval: -19.5 to -3.0] points, p < 0.05). Conclusions: Bilateral kidney stone formers had a younger age of kidney stone disease onset and a higher number of stone events compared with unilateral kidney stone disease formers. The presence of bilateral kidney stone disease negatively impacted HRQOL.