Secondary Data Analysis of Large Data Sets in Urology: Successes and Errors to Avoid

PurposeSecondary data analysis is the use of data collected for research by someone other than the investigator. In the last several years there has been a dramatic increase in the number of these studies being published in urological journals and presented at urological meetings, especially involving secondary data analysis of large administrative data sets. Along with this expansion, skepticism for secondary data analysis studies has increased for many urologists.Materials and methodsIn this narrative review we discuss the types of large data sets that are commonly used for secondary data analysis in urology, and discuss the advantages and disadvantages of secondary data analysis. A literature search was performed to identify urological secondary data analysis studies published since 2008 using commonly used large data sets, and examples of high quality studies published in high impact journals are given. We outline an approach for performing a successful hypothesis or goal driven secondary data analysis study and highlight common errors to avoid.ResultsMore than 350 secondary data analysis studies using large data sets have been published on urological topics since 2008 with likely many more studies presented at meetings but never published. Nonhypothesis or goal driven studies have likely constituted some of these studies and have probably contributed to the increased skepticism of this type of research. However, many high quality, hypothesis driven studies addressing research questions that would have been difficult to conduct with other methods have been performed in the last few years.ConclusionsSecondary data analysis is a powerful tool that can address questions which could not be adequately studied by another method. Knowledge of the limitations of secondary data analysis and of the data sets used is critical for a successful study. There are also important errors to avoid when planning and performing a secondary data analysis study. Investigators and the urological community need to strive to use secondary data analysis of large data sets appropriately to produce high quality studies that hopefully lead to improved patient outcomes

Cumulative incidence of outcomes and urologic procedures after augmentation cystoplasty

ObjectiveAugmentation cystoplasty (AC) is a major surgery that can be associated with long-term morbidity. This study aimed to describe the cumulative incidence of outcomes and urologic procedures in a large cohort of children who underwent AC, identify significant sources of morbidity, and to evaluate baseline factors associated with outcomes of interest.MethodsChildren≤18 years who underwent AC in the Pediatric Health Information System from 1999 to 2010 were included. All follow-up encounters up to June 2012 were included. Cumulative incidences for 15 outcomes and urologic procedures were calculated using non-informative censoring. Sensitivity analyses were performed to determine effect of censoring assumptions and including hospitals without complete datasets. As an exploratory analysis, baseline patient factors were evaluated for associations with outcomes and urologic procedures of interest using multivariable Cox proportional hazards models adjusted for clustering by hospital.Results2831 AC patients were identified. Based on cumulative incidence calculations and sensitivity analyses; the cumulative incidence ranges of outcomes and procedures at 1, 3, 5, and 10 years were calculated. Examples of 10-year cumulative incidence ranges are given for the following outcomes and procedures: bladder rupture (2.9-6.4%), small bowel obstruction (5.2-10.3%), bladder stones (13.3-36.0%), pyelonephritis (16.1-37.1%), cystolithopaxy (13.3-35.1%), and reaugmentation (5.2-13.4%). The development of chronic kidney disease was strongly associated with a diagnosis of lower urinary tract obstruction (HR 13.7; 95% CI 9.4-19.9). Bladder neck surgery and stoma creation at time of AC were associated with an increased hazard of bladder rupture (HR 1.9; 95% CI 1.1-3.3) and bladder stones (HR 1.4; 95% CI 1.1-1.8) respectively.ConclusionsOutcomes of interest and urologic procedures after AC are common. Results from this large cohort can be used to counsel patients and families about expectations after AC. Pyelonephritis, chronic kidney disease, further reconstructive surgery, and calculus disease appear to cause significant morbidity. Collaborative efforts are needed to further reduce morbidity in this patient population

Do adult men with untreated ventral penile curvature have adverse outcomes?

IntroductionCongenital ventral penile curvature without hypospadias is often treated surgically in childhood. The history of untreated ventral curvature is unknown.ObjectiveThis study's aim was to examine the association of untreated ventral penile curvature with various sexual and psychosexual outcomes.Study designAn electronic survey was advertised to men older than 18 years on Facebook. Men with possible ventral penile curvature identified themselves by choosing sketches that most closely represented their anatomy. Outcomes assessed included: Sexual Health Inventory for Men, difficulty of intercourse because of curvature, International Prostate Symptom Score, Penile Perception Score, psychosexual milestones, paternity, infertility, sitting to urinate, and the CDC HRQOL-4 module.ResultsAmong participants, 81 out of 684 men (11.8%) reported untreated ventral penile curvature. Participants with self-reported curvature noted more difficulty with intercourse because of curvature (4.5 vs 4.9, p < 0.001), more unhealthy mental days (8.6 vs 6.2, p = 0.02), and increased dissatisfaction with penile self-perception compared with men without reported curvature (8.6 vs 9.5, p < 0.001).DiscussionMen with possible untreated ventral curvature reported worse penile perception scores, more mentally unhealthy days, and increased difficulty with intercourse secondary to curvature compared with men without curvature. A limitation to this study is selection bias; responses collected were self-reported from survey volunteers. Additionally, the question identifying ventral penile curvature is not validated but performed well in pretesting. Most questions were from validated surveys, but some were modeled after validated surveys and/or contained high face validity types of questions.ConclusionMen with possible untreated ventral penile curvature reported more dissatisfaction with penile appearance, increased difficulty with intercourse, and more unhealthy mental days. Given high success rates, low complications, and improved outcomes after surgical correction of penile curvature reported in the literature, our results support correction of congenital penile curvature in childhood

Repeat urethroplasty after failed urethral reconstruction: outcome analysis of 130 patients.

PurposeMale urethral stricture disease accounts for a significant number of hospital admissions and health care expenditures. Although much research has been completed on treatment for urethral strictures, fewer studies have addressed the treatment of strictures in men with recurrent stricture disease after failed prior urethroplasty. We examined outcome results for repeat urethroplasty.Materials and methodsA prospectively collected, single surgeon urethroplasty database was queried from 1977 to 2011 for patients treated with repeat urethroplasty after failed prior urethral reconstruction. Stricture length and location, and repeat urethroplasty intervention and failure were evaluated with descriptive statistics, and univariate and multivariate logistic regression.ResultsOf 1,156 cases 168 patients underwent repeat urethroplasty after at least 1 failed prior urethroplasty. Of these patients 130 had a followup of 6 months or more and were included in analysis. Median patient age was 44 years (range 11 to 75). Median followup was 55 months (range 6 months to 20.75 years). Overall, 102 of 130 patients (78%) were successfully treated. For patients with failure median time to failure was 17 months (range 7 months to 16.8 years). Two or more failed prior urethroplasties and comorbidities associated with urethral stricture disease were associated with an increased risk of repeat urethroplasty failure.ConclusionsRepeat urethroplasty is a successful treatment option. Patients in whom treatment failed had longer strictures and more complex repairs

Repeat urethroplasty after failed urethral reconstruction: outcome analysis of 130 patients.

PurposeMale urethral stricture disease accounts for a significant number of hospital admissions and health care expenditures. Although much research has been completed on treatment for urethral strictures, fewer studies have addressed the treatment of strictures in men with recurrent stricture disease after failed prior urethroplasty. We examined outcome results for repeat urethroplasty.Materials and methodsA prospectively collected, single surgeon urethroplasty database was queried from 1977 to 2011 for patients treated with repeat urethroplasty after failed prior urethral reconstruction. Stricture length and location, and repeat urethroplasty intervention and failure were evaluated with descriptive statistics, and univariate and multivariate logistic regression.ResultsOf 1,156 cases 168 patients underwent repeat urethroplasty after at least 1 failed prior urethroplasty. Of these patients 130 had a followup of 6 months or more and were included in analysis. Median patient age was 44 years (range 11 to 75). Median followup was 55 months (range 6 months to 20.75 years). Overall, 102 of 130 patients (78%) were successfully treated. For patients with failure median time to failure was 17 months (range 7 months to 16.8 years). Two or more failed prior urethroplasties and comorbidities associated with urethral stricture disease were associated with an increased risk of repeat urethroplasty failure.ConclusionsRepeat urethroplasty is a successful treatment option. Patients in whom treatment failed had longer strictures and more complex repairs

Single Institution Experience with Tru-Cut Renal Mass Biopsy for Diagnosing WilmsTumor

PURPOSE: To evaluate the efficacy of needle biopsy for diagnosing Wilmstumor (WT) before chemotherapy. MATERIALS AND METHODS:We reviewed our institutional experience with Tru-Cut biopsy of pediatric renal masses in patients who subsequently underwent nephrectomy. We compared biopsy pathology with nephrectomy specimens to determine if biopsy accurately predicted final pathology. RESULTS: Seven children underwent Tru-Cut renal mass biopsy followed by surgical resection. In 4 patients, the final biopsy pathology was definitively read as WT and in 3 subjects, the pathology was read as WT versus hyperplastic nephrogenic rest. In all 7 patients, the nephrectomy pathology confirmed a diagnosis of WT. There were no complications after biopsy, and no patients have had local or regional recurrence.CONCLUSION: In our experience, pre-therapy Tru-Cut biopsy safely provides an adequate specimen for pathologic review in diagnosing WT