Percentile Method Research Articles

Spatiotemporal variations of precipitation extremes of China during the past 50 years (1960–2009)

Extreme weather events have become more frequent and intense under global warming in recent years, which has attracted much attention of scholars at home and abroad. In this paper, we used data sets of daily precipitation recorded at 499 meteorological stations to analyze the temporal and spatial variations of precipitation extremes in China over the past 50 years (1960–2009). Through the comparison of detrended fluctuation analysis (DFA) and the percentile method, DFA was selected to define the thresholds of precipitation extremes in China. Temporal variations of extreme precipitation amount, frequency, and intensity were analyzed in four major regions: Northwest China, the Qinghai-Tibet region, North China, and South China. Spatial distributions were obtained by the Kriging interpolation method, and then, we examined the varying tendencies of extreme precipitation amount, frequency, and intensity by the Mann-Kendall test. The results show that increasing trends are dominant for all indices over China; extreme precipitation amount and frequency appear to have risen since 1970–1979, but there are some regional differences. The Qinghai-Tibet region and South China have an ascending trend, and Northwest China maintains balance while North China has a descending trend. The amount and intensity of precipitation extremes are decreasing from southeastern coastal areas to northwestern inlands, and the frequency of precipitation extremes is randomly distributed. However, they are all high in the Sichuan Basin, the middle and lower Yangtze River, and the southern part of South China. Trends of most stations are statistically insignificant, but the percentage of stations with a significant increased trend in the Qinghai-Tibet region is larger than that of other regions.

Defining normality in a European multinational cohort: Critical factors influencing the 99th percentile upper reference limit for high sensitivity cardiac troponin I

ObjectiveTo establish and critically evaluate the 99th percentile upper reference limit (URL) for high-sensitivity cardiac troponin I (hs-cTnI) in a large healthy European cohort using different selection criteria. Methods1368 presumably healthy individuals from 9 countries were evaluated with surrogate biomarkers for diabetes (glycated hemoglobin [HbA1c] <48mmol/mol), myocardial (B-type natriuretic peptide [BNP] <35pg/mL) and renal dysfunction (estimated glomerular filtration rate [eGFR] >60mL/min/1.73m2), and dyslipidemia to refine the healthy cohort. The 99th percentile URLs were independently determined by the non-parametric and robust methods. ResultsThe use of biomarker selection criteria resulted in a decrease of the 99th percentile URL for hs-cTnI from 23.7 to 14.1ng/L and from 11.2 to 7.1ng/L, when using the non-parametric percentile and robust methods, respectively; a further reduction after exclusion of individuals with dyslipidemia was noted. Male gender, BNP, HbA1c and smoking status were independently associated with hs-cTnI concentration in the presumably healthy population, while the impact of age, present in the univariate analysis, decreased after adjustments for gender and surrogate biomarkers. The BNP-based inclusion criterion had the most pronounced effect on the 99th percentile URL, excluding 21% of the study participants and decreasing its value to 11.0 (7.1) ng/L according to the non-parametric (robust) method. Gender, but not age-specific, differences at 99th percentile URL have been identified. ConclusionThe selection of a reference population has a critical impact on the 99th percentile value for hs-cTnI. A uniform protocol for the selection of the healthy reference population is needed.

Intercomparison of textural parameters of intertidal sediments generated by different statistical procedures, and implications for a unifying descriptive nomenclature

Grain-size analysis is a basic routine in sedimentology and related fields, but diverse methods of sample collection, processing and statistical analysis often make direct comparisons and interpretations difficult or even impossible. In this paper, 586 published grain-size datasets from the Qiantang Estuary (East China Sea) sampled and analyzed by the same procedures were merged and their textural parameters calculated by a percentile and two moment methods. The aim was to explore which of the statistical procedures performed best in the discrimination of three distinct sedimentary units on the tidal flats of the middle Qiantang Estuary. A Gaussian curve-fitting method served to simulate mixtures of two normal populations having different modal sizes, sorting values and size distributions, enabling a better understanding of the impact of finer tail components on textural parameters, as well as the proposal of a unifying descriptive nomenclature. The results show that percentile and moment procedures yield almost identical results for mean grain size, and that sorting values are also highly correlated. However, more complex relationships exist between percentile and moment skewness (kurtosis), changing from positive to negative correlations when the proportions of the finer populations decrease below 35% (10%). This change results from the overweighting of tail components in moment statistics, which stands in sharp contrast to the underweighting or complete amputation of small tail components by the percentile procedure. Intercomparisons of bivariate plots suggest an advantage of the Friedman & Johnson moment procedure over the McManus moment method in terms of the description of grain-size distributions, and over the percentile method by virtue of a greater sensitivity to small variations in tail components. The textural parameter scalings of Folk & Ward were translated into their Friedman & Johnson moment counterparts by application of mathematical functions derived by regression analysis of measured and modeled grain-size data, or by determining the abscissa values of intersections between auxiliary lines running parallel to the x-axis and vertical lines corresponding to the descriptive percentile limits along the ordinate of representative bivariate plots. Twofold limits were extrapolated for the moment statistics in relation to single descriptive terms in the cases of skewness and kurtosis by considering both positive and negative correlations between percentile and moment statistics. The extrapolated descriptive scalings were further validated by examining entire size-frequency distributions simulated by mixing two normal populations of designated modal size and sorting values, but varying in mixing ratios. These were found to match well in most of the proposed scalings, although platykurtic and very platykurtic categories were questionable when the proportion of the finer population was below 5%. Irrespective of the statistical procedure, descriptive nomenclatures should therefore be cautiously used when tail components contribute less than 5% to grain-size distributions.

Airway wall thickness associated with forced expiratory volume in 1 second decline and development of airflow limitation.

Airway wall thickness and emphysema contribute to airflow limitation. We examined their association with lung function decline and development of airflow limitation in 2021 male smokers with and without airflow limitation. Airway wall thickness and emphysema were quantified on chest computed tomography and expressed as the square root of wall area of a 10-mm lumen perimeter (Pi10) and the 15th percentile method (Perc15), respectively. Baseline and follow-up (median (interquartile range) 3 (2.9-3.1) years) spirometry was available. Pi10 and Perc15 correlated with baseline forced expiratory volume in 1 s (FEV1) (r= -0.49 and 0.11, respectively (p<0.001)). Multiple linear regression showed that Pi10 and Perc15 at baseline were associated with a lower FEV1 after follow-up (p<0.05). For each sd increase in Pi10 and decrease in Perc15 the FEV1 decreased by 20 mL and 30.2 mL, respectively. The odds ratio for developing airflow limitation after 3 years was 2.45 for a 1-mm higher Pi10 and 1.46 for a 10-HU lower Perc15 (p<0.001). A greater degree of airway wall thickness and emphysema was associated with a higher FEV1 decline and development of airflow limitation after 3 years of follow-up.

A comparison of the parameter estimation methods for bimodal mixture Weibull distribution with complete data

Bimodal mixture Weibull distribution being a special case of mixture Weibull distribution has been used recently as a suitable model for heterogeneous data sets in many practical applications. The bimodal mixture Weibull term represents a mixture of two Weibull distributions. Although many estimation methods have been proposed for the bimodal mixture Weibull distribution, there is not a comprehensive comparison. This paper presents a detailed comparison of five kinds of numerical methods, such as maximum likelihood estimation, least-squares method, method of moments, method of logarithmic moments and percentile method (PM) in terms of several criteria by simulation study. Also parameter estimation methods are applied to real data.

Home blood pressure profile in very elderly hypertensives: should we use the same thresholds as in younger patients?

We aimed to determine the characteristics of home blood pressure (BP) in very elderly hypertensives. A total of 485 treated hypertensive patients ≥18 years (median age, 70.8 [interquartile range, 18]; 67.2% women) underwent home BP measurements. Characteristics of patients ≥80 and <80 years of age and prevalence of office and home uncontrolled hypertension, isolated morning (IMH), isolated evening, isolated office, and masked hypertension were compared. Very elderly subjects had higher levels of systolic and lower levels of diastolic BP at home, a higher prevalence of home uncontrolled hypertension (68.5% vs. 37.7%; P < .001), masked hypertension (30.6% vs. 14.9%; P = .02), and IMH (19.4% vs. 10.9%; P = .02), and a lower prevalence of isolated office hypertension (8.3% vs. 18.8%; P = .01). When using differential home BP thresholds in the very elderly, determined through the percentile method, statistical differences disappeared, except for IMH. The very elderly depict a particular home BP profile. Benefit from using differential home BP thresholds should be determined in prospective studies.

Probabilistic Approach for Evaluating the Capacity Value of Intermittent Generation

SUMMARYSeveral approaches have been proposed for evaluating the capacity value of intermittent generation. In this paper, we assume that the uncertainty included in demand, existing generation, and intermittent generation, can be treated by means of a normal distribution model. Using a newly developed approximation method similar to the Garver approximation, and the Z‐stochastic approach, the effective load carrying capability method is comprehensively surveyed. The percentile method adopted in the higher demand level is also discussed in connection with the probabilistic properties of intermittent generation. Numerical examples and a simulation illustrating the probabilistic approach are included.

Understanding Patients Perspective on Clinical Research in Indian Population

Objective: To understand patient’s perspectives on clinical research in India. Design: A questionnaire based survey was conducted in different parts of India, covering all kind of population. Questionnaires were filled with the help of investigators, physicians, social workers, freelancers, and research professionals, etc. Methods: India is said to be the hub of clinical research. It is also equivalently important that the Indian population remain well aware about the basics of clinical research so that individuals are not treated as “guinea pigs” and the research is conducted with full ethics and good clinical practice. The study was undertaken to analyze the perspective and awareness of clinical research amongst Indian population. Results: There were 20 different parameters/data points for which the data was collected from 6122 patients across the country. As the available data is dichotomous a dynamic analysis was done using a percentile method. Conclusion: Though Central Drugs Standard Control Organization (CDSCO) – the office of the Drug Controller General (India), the supreme regulatory authority for clinical research in India, has framed necessary guidelines and schedules to oversee that clinical trials are conducted in ethical manner still the understanding of patients remains ambiguous. The data concludes that awareness about clinical research remains low. Better public awareness will help us bring new therapies to the market.

Power Laws In Financial Markets: Scaling Exponent H And Alpha-Stable Distributions

In this study, we analyzed whether daily returns of Brent crude oil, dollar/yen foreign exchange, Dow&amp;Jones Industrial Average Index and 12-month libor display power law features in the scaling exponent and probability distributions or not, using different methods. Due to the fact that the simulated time series with different values showed the robustness of Higuchis Fractal Dimension and Pengs Statistic, we used these two models in the analysis of the scaling features of the returns. On the other hand, in order to examine power law behaviors of probability distributions, we estimated parameters of the alpha-stable distributions for the return series using the Ecf and Percentile methods. Results showed that the Brent crude oil and 12-month libor have a high persistency in the returns, while the dollar/yen foreign exchange and Dow&amp;Jones Industrial Average Index returns have short memory. According to the alpha-stable parameter estimations, all of the return series have thicker tails than normal distribution. Similar to the highest persistency of 12-month libor returns in the scaling exponent analysis, we have seen that this variable also has the thickest tails in the probability distributions, meaning that 12-month libor returns have the highest power law features within the series.

Fair, Flexible and Feasible ISP Billing

The 95th percentile method for calculating a customer's billable transit volume has been the industry standard used by transit providers for over a decade due to its simplicity. We recently showed [1] that 95th percentile billing can be unfair, in that it does not reflect a customer's contribution to the provider's peak load. The 95th percentile method is also inflexible, as it does not allow a provider to offer incentives to customers that contribute minimally to the provider's peak load. In this paper we propose a new transit billing optimization framework that is fair, flexible and computationally inexpensive. Our approach is based on the Provision Ratio, a metric that estimates the contribution of a customer to the provider's peak traffic. The proposed mechanism has fairness properties similar to the optimal (in terms of fairness) Shapley value allocation, with a much smaller computational complexity.

Reference interval for immature platelet fraction on Sysmex XN hematology analyzer: a comparison study with Sysmex XE-2100.

Recently introduced hematology analyzer, the Sysmex XN modular system (Sysmex, Kobe, Japan), has newly adopted a florescent channel to detect platelets and immature platelet fraction (IPF). This study aimed to establish new reference intervals for %-IPF and absolute number of IPF (A-IPF) on Sysmex XN. Platelet counts, %-IPF, and A-IPF were also compared between Sysmex XN and XE-2100 systems (Sysmex). Except outliers, blood samples from 2104 healthy individuals and 140 umbilical cord blood were analyzed using both Sysmex XN and XE-2100. The results of two systems were compared using Bland-Altman plot. The reference intervals for %-IPF and A-IPF were defined using non-parametric percentile methods according to the Clinical and Laboratory Standard Institute guideline (C28-A3). The platelet counts, %-IPF, and A-IPF showed non-parametric distributions. The mean difference between Sysmex XN and XE-2100 in healthy individuals revealed a positive bias in platelets (+8.0×109/L), %-IPF (+1.2%), and A-IPF (+3.0×109/L). The reference intervals for %-IPF and A-IPF on Sysmex XN were: 1.0%-7.3% and 2.49-15.64×109/L in healthy individuals; and 1.0%-4.4% and 2.94-12.82×109/L in umbilical cord blood. This large-scale study demonstrates a clear difference of platelet counts and IPF between Sysmex XN and XE-2100. The new reference intervals for IPF on Sysmex XN would provide fundamental data for clinical practice and future research.

Application of x-ray computed tomography in the evaluation of soil porosity in soil management systems

The study aimed to evaluate a methodology to quantify the porosity of the soil using computed tomography in areas under no-tillage, conventional tillage and native forest. Three soil management systems were selected for the study: forest, conventional tillage and no-tillage. In each soil management system, undisturbed soil samples were collected in the surface layer (0.0 to 0.10 m). The tomographic images were obtained using a X-ray microtomography. After obtaining the images, they were processed, and a methodology was evaluated for image conversion into numerical values. The statistical method which provided the greatest accuracy was the percentile method. The methodology used to analyze the tomographic image allowed quantifying the porosity of the soil under different soil management. The method enabled the characterization of soil porosity in a non-evasive and non-destructive way.

Double Bootstrap Confidence Interval Estimates with Censored and Truncated Data

Traditional inferential procedures often fail with censored and truncated data, especially when sample sizes are small. In this paper we evaluate the performances of the double and single bootstrap interval estimates by comparing the double percentile (DB-p), double percentile-t (DB-t), single percentile (B-p), and percentile-t (B-t) bootstrap interval estimation methods via a coverage probability study when the data is censored using the log logistic model. We then apply the double bootstrap intervals to real right censored lifetime data on 32 women with breast cancer and failure data on 98 brake pads where all the observations were left truncated.

Evaluation of the performance of a dengue outbreak detection tool for China.

An outbreak detection and response system, using time series moving percentile method based on historical data, in China has been used for identifying dengue fever outbreaks since 2008. For dengue fever outbreaks reported from 2009 to 2012, this system achieved a sensitivity of 100%, a specificity of 99.8% and a median time to detection of 3 days, which indicated that the system was a useful decision tool for dengue fever control and risk-management programs in China.

Smoothed and iterated bootstrap confidence regions for parameter vectors

The construction of confidence regions for parameter vectors is a difficult problem in the nonparametric setting, particularly when the sample size is not large. We focus on bootstrap ellipsoidal confidence regions. The bootstrap has shown promise in solving this problem, but empirical evidence often indicates that the bootstrap percentile method has difficulty in maintaining the correct coverage probability, while the bootstrap percentile- t method may be unstable, often resulting in very large confidence regions. This paper considers the smoothed and iterated bootstrap methods to construct the bootstrap percentile method ellipsoidal confidence region. The smoothed bootstrap method is based on a multivariate kernel density estimator. An optimal bandwidth matrix is established for the smoothed bootstrap procedure that reduces the coverage error of the bootstrap percentile method. We also provide an analytical adjustment to the nominal level to reduce the computational cost of the iterated bootstrap method. Simulations demonstrate that the methods can be successfully applied in practice.

The significance of serum N-terminal pro-brain natriuretic peptide levels for prognosis of patients in intensive care unit

To assess the significance of elevated serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in predicting 30-day mortality rate for patients in intensive care unit (ICU). A retrospective study was conducted. The clinical data of 480 patients admitted to ICU in Tianjin First Center Hospital from June 2012 to October 2013 were studied. The characteristics of patients were recorded, the acute physiology and chronic health evaluationII ( APACHEII) score was calculated, and the routine blood tests, blood biochemistry, and serum NT-proBNP level within 24 hours after admission were determined. Patients were divided into non-survival and survival groups according to 30-day outcome, and the characteristics and clinical parameters were compared between two groups, and single factor analysis affecting prognosis was analyzed. All patients were divided into four groups according to four percentile method as NT-proBNP<280 ng/L (group Q1), 280 ng/L≤NT-proBNP<1 200 ng/L (group Q2), 1 200 ng/L≤NT-proBNP<1 990 ng/L (group Q3), 1 990 ng/L≤NT-proBNP<4 700 ng/L (group Q4). A Cox regression analysis was used to test the independence of the predictors. A receiver operator characteristic curve (ROC curve) was plotted to compare the power of APACHEII score and NT-proBNP in predicting the outcome. Kaplan-Meier analysis was used to assess survival rate among different NT-proBNP patients. By single factor analysis it was shown that age, APACHEII score, creatinine, NT-proBNP and severe infection were those influencing the outcome. NT-proBNP 1 200-4 700 ng/L (groups Q3 and Q4) and APACHEII score>20 were independent risk factors for predicting outcome [relative risk (RR) for group Q3 was 3.624, 95% credibility interval (95%CI) was 1.258-10.138; RR for group Q4 was 5.059, 95%CI was 3.202-9.993; RR for APACHEII score>20 was 2.987, 95%CI was 1.345-5.823]. The area under the ROC curve (AUC) for APACHEII score and serum NT-proBNP was similar, and it was 0.831 (95%CI 0.778-0.884) and 0.876 (95%CI 0.827-0.925), respectively. The cut-off value of NT-proBNP for predicting mortality was 1 250 ng/L. Kaplan-Meier analysis showed that groups of Q2, Q3 and Q4 had lower cumulative survival rate compared with group Q1 (26.5%, 25.4%, 16.2% vs. 29.6%), and group Q4 showed most significant extent of lowering of survival rate (χ(2)=122.920, P<0.05). Elevated NT-proBNP level in ICU patients signify severity of the disease, and it is an independent predictor of death of ICU patients.

Unification of the Urban Minimum Living Standard in China: Using a Consumption Expenditure Percentile Method

ABSTRACT. The Minimum Living Standard Guarantee (MLSG) system in urban China was established in the 1990s. As a national income benefit program, this system has huge regional differences as a result of regional variation in economic development and the methods used to calculate the benefit. This article uses a consumption expenditure percentile method to measure and evaluate the benefit level of the MLSG system. The analysis shows that the consumption expenditure replacement rates in central cities are decreasing, but in prefectural-level cities, by contrast, they are increasing. The regional differences in replacement rates when comparing central cities are considerable and are even larger among cities at a prefecture level. Per-capita consumption expenditure is positively correlated with minimal living standards but negatively correlated with the replacement rate. Such variation in the value and operation of the MLSG system suggests an urgent need to implement a national unified scheme. The article proposes a single approach to calculating Minimum Living Standard benefits using a consumption expenditure replacement rate that would allow for local differences while providing national cohesion.

Development of Neglect Evaluation Scale for primary school students aged 6-11 years old in rural areas of China

To develop a standard Neglect Evaluation Scale which is suitable for rural primary school students in China. According to the principle of multi-stage stratified cluster sampling, a field investigation was conducted among primary school students in 28 counties from 7 provinces and 2 municipalities. The questionnaires were self-designed, and determined by multiple rounds of pilots and revisions. Among 5 862 students, 2 792 (6-8 years' old) and 3 070 (9-11 years' old) were investigated by using two kinds of Neglect Evaluation questionnaires, respectively. After project analysis, factor analysis, reliability and validity analysis, the reliability and stability of the scale were tested. Then percentile method was used to determine the evaluation standard to develop and finalize the formal scale. The numbers of the remaining items for 6-8 year-old group and 9-11 year-old group is 69 and 58, respectively, both of which contain six levels of neglect, including body, emotion, health care, education, security, and society. 4 times of factor analysis were conducted in both of the two groups. The factor loadings in these two groups were 0.290-0.700 and 0.276-0.729 respectively. Reliability test results showed that the two kinds of scales' Cronbach alpha coefficient were 0.924 and 0.929 respectively, split-half reliability were 0.891 and 0.904 respectively, the retest reliability were 0.559 and 0.892 respectively, the differences were statistically significant (P < 0.05). The retest reliability among 6-8 year-old group in medical neglect level had no statistical significance, but was close to the cut-off point (P = 0.054). The test results of external validity indicated that both of the two scales could reflect the neglect status of the subjects (P < 0.05), but the subjective and objective evaluation towards neglect were not consistent. The cut-off points for judging whether the children were neglected or not among 6-8 year-old and 9-11 year-old groups were 159 and 137 respectively; and the adjusted values were 160 and 135 respectively. The two norm scales developed by this study showed good discriminability, reliability, validity, and stability. The norms developed on the basis of the scales was suitable for the situation of rural students in primary schools in China.

MP2-04 EVALUATION OF THE ACS NSQIP SURGICAL RISK CALCULATOR IN PATIENTS UNDERGOING RADICAL CYSTECTOMY

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Evidence-based Medicine & Outcomes II1 Apr 2014MP2-04 EVALUATION OF THE ACS NSQIP SURGICAL RISK CALCULATOR IN PATIENTS UNDERGOING RADICAL CYSTECTOMY Jeffrey Tomaszewski, Elizabeth Handorf, Alexander Kutikov, Reza Mehrazin, Bic Cung, Simon Kim, Rosalia Viterbo, David Chen, Richard Greenberg, Henry Pitt, Nestor Esnaola, Robert Uzzo, and Marc Smaldone Jeffrey TomaszewskiJeffrey Tomaszewski More articles by this author , Elizabeth HandorfElizabeth Handorf More articles by this author , Alexander KutikovAlexander Kutikov More articles by this author , Reza MehrazinReza Mehrazin More articles by this author , Bic CungBic Cung More articles by this author , Simon KimSimon Kim More articles by this author , Rosalia ViterboRosalia Viterbo More articles by this author , David ChenDavid Chen More articles by this author , Richard GreenbergRichard Greenberg More articles by this author , Henry PittHenry Pitt More articles by this author , Nestor EsnaolaNestor Esnaola More articles by this author , Robert UzzoRobert Uzzo More articles by this author , and Marc SmaldoneMarc Smaldone More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.162AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The National Surgical Quality Improvement Project (NSQIP) Surgical Risk Calculator is a tool created by the American College of Surgeons (ACS) to estimate risk adjusted peri-operative outcomes for commonly performed surgical procedures as a means to measure and improve quality of surgical care. Our objective was to evaluate the accuracy of the Surgical Risk Calculator in patients treated with radical cystectomy (RC) for urothelial carcinoma of the bladder. METHODS A prospectively maintained, institutional, database was queried for all patients undergoing RC from 2007-2011. For each patient, 22 designated preoperative risk factors were entered into the NSQIP calculator to obtain estimates of 30 day peri-operative mortality, post-operative complications, and hospital length of stay (HLOS). To assess overall calibration of risks predicted by the Surgical Risk Calculator, we calculated the difference between mean predicted risk and the observed rate of surgical outcomes in our cohort. To assess statistical significance of differences between observed and expected outcomes, we used a bootstrap with 1,000 replicates, calculated confidence intervals via the percentile method, and determined p-values using two-sided pivot tests. RESULTS 314 patients undergoing RC were included for analysis. All patients had complete data available for pre-and post-operative risk assessment. Comparing observed to expected events, the NSQIP calculator significantly underestimated the risks of death (-3.3% [CI -1.3--5.4]; p=0.002), serious complications (-19.4% [CI -14.1- -24.5]; p<0.001), overall complications (-23.4% [CI -17.6--28.5]; p<0.001), surgical site infections (-5.8% [CI -1.8--9.6]; p=0.002), urinary tract infections (-15.2% [CI -10.8--19.7]; p<0.001), acute renal failure (-3.2% [CI -0.9--6.1]; p=0.008), and hospital length of stay (-4.8 days [CI -3.8--6.0]; p<0.001). There were no significant differences between predicted and observed rates of pneumonia, cardiac morbidity, venous thromboembolism, or need for return to the operating room. CONCLUSIONS Patients undergoing RC had significant differences in several observed versus expected peri-operative outcomes estimated with the ACS NSQIP Surgical Risk Calculator. Growing participation by hospitals in the ACS NSQIP’s Procedure Targeted Option, and creation/incorporation of procedure (e.g. RC)-specific preoperative risk factors and outcomes will likely enhance the accuracy of surgical outcomes estimation by the Surgical Risk Calculator. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e25-e26 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Jeffrey Tomaszewski More articles by this author Elizabeth Handorf More articles by this author Alexander Kutikov More articles by this author Reza Mehrazin More articles by this author Bic Cung More articles by this author Simon Kim More articles by this author Rosalia Viterbo More articles by this author David Chen More articles by this author Richard Greenberg More articles by this author Henry Pitt More articles by this author Nestor Esnaola More articles by this author Robert Uzzo More articles by this author Marc Smaldone More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP2-05 IDENTIFYING PATIENTS AT HIGH-RISK FOR READMISSION AFTER RADICAL CYSTECTOMY USING THE NATIONAL SURGICAL QUALITY IMPROVEMENT PROGRAM DATABASE

Calculator, we calculated the difference between mean predicted risk and the observed rate of surgical outcomes in our cohort. To assess statistical significance of differences between observed and expected outcomes, we used a bootstrap with 1,000 replicates, calculated confidence intervals via the percentile method, and determined p-values using two-sided pivot tests. RESULTS: 314 patients undergoing RC were included for analysis. All patients had complete data available for pre-and postoperative risk assessment. Comparing observed to expected events, the NSQIP calculator significantly underestimated the risks of death (3.3% [CI 1.3-5.4]; p1⁄40.002), serious complications (19.4% [CI 14.124.5]; p<0.001), overall complications (23.4% [CI 17.6-28.5]; p<0.001), surgical site infections (5.8% [CI 1.8-9.6]; p1⁄40.002), urinary tract infections (15.2% [CI 10.8-19.7]; p<0.001), acute renal failure (3.2% [CI 0.9-6.1]; p1⁄40.008), and hospital length of stay (4.8 days [CI 3.8-6.0]; p<0.001). There were no significant differences between predicted and observed rates of pneumonia, cardiac morbidity, venous thromboembolism, or need for return to the operating room. CONCLUSIONS: Patients undergoing RC had significant differences in several observed versus expected peri-operative outcomes estimated with the ACS NSQIP Surgical Risk Calculator. Growing participation by hospitals in the ACS NSQIP’s Procedure Targeted Option, and creation/incorporation of procedure (e.g. RC)-specific preoperative risk factors and outcomes will likely enhance the accuracy of surgical outcomes estimation by the Surgical Risk Calculator.