Unmatched Dataset Research Articles

1830 PROPENSITY SCORE ANALYSIS OF COMPARATIVE EFFECTIVENESS: PERCUTANEOUS NEPHROLITHOTOMY VERSUS STAGED URETEROSCOPY FOR KIDNEY STONES BETWEEN 2 AND 4 CENTIMETERS

You have accessJournal of UrologyStone Disease: New Technology/SWL, Ureteroscopic or Percutaneous Stone Removal III1 Apr 20121830 PROPENSITY SCORE ANALYSIS OF COMPARATIVE EFFECTIVENESS: PERCUTANEOUS NEPHROLITHOTOMY VERSUS STAGED URETEROSCOPY FOR KIDNEY STONES BETWEEN 2 AND 4 CENTIMETERS Emily Scott, Dan Winger, Samih Al-Hayek, Joel Bigley, Khaled Shahrour, Stephen Jackman, and Timothy Averch Emily ScottEmily Scott Pittsburgh, PA More articles by this author , Dan WingerDan Winger Pittsburgh, PA More articles by this author , Samih Al-HayekSamih Al-Hayek Pittsburgh, PA More articles by this author , Joel BigleyJoel Bigley Pittsburgh, PA More articles by this author , Khaled ShahrourKhaled Shahrour Pittsburgh, PA More articles by this author , Stephen JackmanStephen Jackman Pittsburgh, PA More articles by this author , and Timothy AverchTimothy Averch Pittsburgh, PA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1918AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Historically, the standard for the treatment of large stone burdens is percutaneous nephrolithotomy (PCNL). However, staged ureteroscopy (SURS) is being used more frequently to treat these stones. This study evaluates the comparative effectiveness of these procedures in treating stones between 2 and 4 centimeters in diameter using propensity score analysis. METHODS With IRB approval, all PCNL patients' charts from 2000 to 2010 with stones between 2 and 4 centimeters were reviewed. Patients with staghorn stones were also excluded, as their probability of receiving a PCNL procedure was much greater than an SURS procedure. SURS patients that met the same criteria were selected for between 2005 and 2010. A comparison of the two procedures was performed analyzing complications, hospital length of stay (HLOS), patients requiring a second look, and overall stone free success rate. Propensity score analysis accounted for nonrandom assignment of the two procedures. The propensity scores took into account a variety of risk factors not balanced in the original dataset (I.e. BMI, diabetes, coagulopathy, various stone characteristics, etc.). Propensity scores were used to either construct matched data sets for paired comparisons or to adjust traditional unmatched regression methods. RESULTS 158 PCNL patients and 41 SURS patients with valid data were used, and propensity score analysis with caliper matching was generated into a matched data set of 29 patients in each group. Based on this matched data set, there was no difference in the complication rate of the two procedures (PCNL 6.90%, SURS 3.45%, exact p-value = 1.00). Also, there was no difference in the success of the two procedures (stone free overall, PCNL 89.7%, SURS 86.2%, exact p-value = 1.00). There was a difference, however, in HLOS (PNCL 2.31, SURS 0.03, p-value < 0.001) and in rate of second look (PCNL 37.9%, SURS 89.7%, p-value < 0.001). Other methods of statistical analysis included traditional regression methods adjusting for propensity scores, which used the entire unmatched dataset, and produced the same above conclusions as the matched analysis. CONCLUSIONS The use of propensity score analysis showed no significant difference between PCNL and SURS in complication and stone free rates for stones of this size. PCNL resulted in a longer HLOS, and SURS had a higher rate of second look. The data suggests that SURS should be considered as an alternative treatment in appropriate patients with this magnitude of stone burden. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e740 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Emily Scott Pittsburgh, PA More articles by this author Dan Winger Pittsburgh, PA More articles by this author Samih Al-Hayek Pittsburgh, PA More articles by this author Joel Bigley Pittsburgh, PA More articles by this author Khaled Shahrour Pittsburgh, PA More articles by this author Stephen Jackman Pittsburgh, PA More articles by this author Timothy Averch Pittsburgh, PA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Demographics of populations at high risk of lung cancer and results of the Early CDT-Lung test.

7033 Background: EarlyCDT-Lung measures autoantibodies (AABs) to six cancer-associated antigens (p53, NY- ESO-1, CAGE, GBU4-5, Annexin1, and SOX2) and has been reported to identify up to 40% of lung cancers, both early- and late-stage disease. Methods: Prospective blood collections (with individual questionnaires) were carried out in three different community-based locations in two countries (US, two sites; UK, one site) in order to assess demographic features of high-risk populations. Some demographic features were not recorded at all sites. For the statistical comparisons, analysis of variance was generally used, taking into account imbalance in subgroup numbers, unevaluable data and multiplicity of testing, where necessary, and with sample-matching, where appropriate. Results: Unmatched Datasets: from separate analyses of the US (Florida n=320, Midwest n=940) and UK (n=2046) datasets there was no difference for any of the AAB assays between (i) males and females, (ii) the main ethnic groups (US only) f...

Diagnosis of meniscal tears of the knee with MR imaging: effect of observer variation and sample size on sensitivity and specificity.

A wide range in the efficacy of MR imaging for the diagnosis of meniscal tears of the knee has been reported. To evaluate two possible causes for this variation, we studied how sensitivity and specificity are affected when different observers and sample sizes are used. Two hundred MR examinations of the knee in patients for whom the results of arthroscopy were available were used for the study. One hundred eight medial meniscal tears and 58 lateral meniscal tears were found at arthroscopy. The sensitivity and specificity for detection of meniscal tears were determined for the original interpretations and retrospective evaluations by three observers. Comparisons were also made between sample sizes of 25 and 100. chi 2 analysis was used for unmatched data sets and McNemar's statistic was used for matched sets. For the 200 examinations, the sensitivity was 0.89-0.93 for medial meniscal tears and 0.79-0.83 for lateral meniscal tears. The specificity was 0.86 for medial meniscal tears and 0.90-0.92 for lateral meniscal tears. Sensitivity and specificity varied widely among different observers and different sample sizes. However, we found no significant difference between any of the comparisons at the p < .05 level. The largest interobserver variation occurred in the detection of lateral meniscal tears, with a sensitivity of 0.71 for one observer and 0.88 for another observer (p = .16). The largest variation between sets of 100 examinations was a change in sensitivity for detection of lateral meniscal tears from 0.74 to 0.88 for the original interpretations (p = .10). For the sample sets of 25 cases, the variation was even larger, with the sensitivity for detection of lateral meniscal tears varying from 0.5 for one set to 1.0 for another. We conclude that chance variation related to sample size can cause large but not statistically significant variations in sensitivity and specificity in this setting. These variations are of sufficient magnitude to explain many of the differences in reported sensitivity and specificity for MR imaging in the diagnosis of meniscal tears. We found no significant difference in observer performance.