User Data File Research Articles

Diversity in Renal Mass Data Cohorts: Implications for Urology AI Researchers

Introduction: We examine the heterogeneity and distribution of the cohort populations in two publicly used radiological image cohorts, the Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma (TCIA TCGA KIRC) collection and 2019 MICCAI Kidney Tumor Segmentation Challenge (KiTS19), and deviations in real-world population renal cancer data from the National Cancer Database (NCDB) Participant User Data File (PUF) and tertiary center data. PUF data are used as an anchor for prevalence rate bias assessment. Specific gene expression and, therefore, biology of RCC differ by self-reported race, especially between the African American and Caucasian populations. AI algorithms learn from datasets, but if the dataset misrepresents the population, reinforcing bias may occur. Ignoring these demographic features may lead to inaccurate downstream effects, thereby limiting the translation of these analyses to clinical practice. Consciousness of model training biases is vital to patient care decisions when using models in clinical settings. Methods: Data elements evaluated included gender, demographics, reported pathologic grading, and cancer staging. American Urological Association risk levels were used. Poisson regression was performed to estimate the population-based and sample-specific estimation for prevalence rate and corresponding 95% confidence interval. SAS 9.4 was used for data analysis. Results: Compared to PUF, KiTS19 and TCGA KIRC oversampled Caucasian by 9.5% (95% CI, −3.7 to 22.7%) and 15.1% (95% CI, 1.5 to 28.8%), undersampled African American by −6.7% (95% CI, −10% to −3.3%), and −5.5% (95% CI, −9.3% to −1.8%). Tertiary also undersampled African American by −6.6% (95% CI, −8.7% to −4.6%). The tertiary cohort largely undersampled aggressive cancers by −14.7% (95% CI, −20.9% to −8.4%). No statistically significant difference was found among PUF, TCGA, and KiTS19 in aggressive rate; however, heterogeneities in risk are notable. Conclusion: Heterogeneities between cohorts need to be considered in future AI training and cross-validation for renal masses.

MBSAQIP database: are the data reliable?

BackgroundThe Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database collects data from all accredited centers in the US. A prior study showed data quality issues limiting use of up to 20% of the 2015 database. ObjectivesTo evaluate the completeness and data quality (internal validity, accuracy, and consistency) of the MBSAQIP database between 2015 and 2019. SettingUnited States. MethodsAll subsets of data from the MBSAQIP Participant User Data File (PUDF) were compiled into one main file. Completeness, internal validity, accuracy, and consistency were evaluated. Completeness was determined via missing values. Internal validity was assessed using the percentage of patients with a body mass index (BMI) < 30 kg/m2 who underwent primary bariatric surgery. Accuracy was evaluated using reported versus calculated BMI. Consistency was assessed using the percentage of patients with a gain of >5 or a loss of >20 units of BMI change in 30 days. Effects across years were assessed using a chi-squared test. ResultsMissing data for age, BMI, and ASA was consistently low (<2.5%) with no significant difference across years. Only .02% of patients who underwent a primary bariatric procedure had a reported BMI <30 kg/m2. The mean difference between reported versus calculated BMI was −.02 units. A maximum of .33% of patients gained >5 units of BMI, and a maximum of .85% of patients lost > 20 units of BMI in early follow-up. ConclusionsWhile the MBSAQIP is a database with acceptable data quality and minimal changes from 2015–2019, ongoing efforts are needed to improve data.

Current Trends in the Utilization of a Robotic Approach in the Field of Bariatric Surgery.

The utilization rate of robotic surgery for bariatric procedures is not well-described. Our study identified the proportion of metabolic and bariatric surgery (MBS) procedures in the United States between 2015 and 2020 performed using a robotic (R-) or laparoscopic (L-) approach. A descriptive analysis of the 2015-2020 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) Participant User Data File (PUF) datasets was performed. The primary outcome was (1) surgical cases performed annually and (2) proportion of cases performed using a R- or L- approach. Analysis was done separately for sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion with duodenal switch (BPD-DS), and revisional bariatric surgery (RBS). Statistical analysis consisted of means and proportions, fold difference, annual slope, and Student's t tests or chi-square tests as appropriate, with statistical significance set to p < .05. A total of 1,135, 214 procedures were captured between 2015 and 2020. R-RYGB increased from 2554 to 6198 (6.8% to 16.7%), R-SG increased from 5229 to 17,063 (6.0% to 17.2%), R-RBS increased from 993 to 3386 (4.7% to 17.4%), and R-BPD-DS increased from 221 to 393 (22.0% to 28.4%). The greatest annual increase was observed among R-RBS and R-SG (3.70-fold difference; slope 2.4% per year and 2.87-fold difference; slope2.2% per year, respectively). There is a nationwide increase in the utilization of a R- approach in bariatric surgery. There are concerns related to the potential increase in healthcare expenditures related to robotics. Further studies are needed to establish key performance indicatorsalong with guidelines for training, adoption and utilization of a R- approach.

Pylorus-Preservation Pancreatoduodenectomy Is Associated with Higher Rate of Delayed Gastric Emptying in Patients with Intermediate/High Risk for Pancreatic Fistula

INTRODUCTION: The association between delayed gastric emptying (DGE) and pylorus-preserving pancreatoduodenectomy (PPPD) vs classic pancreatoduodenectomy (PD) remains controversial. This study aims to identify preoperative and intraoperative factors associated with DGE based on the well-established pancreatic fistula risk score (FRS). We hypothesized that a stratified approach to surgical technique selection may be beneficial given the association of DGE with postoperative pancreatic fistula (POPF). METHODS: The 2014 to 2019 NSQIP pancreatectomy Participant User Data File (PUF) was queried for patients who underwent PPPD or PD. Multivariable logistic regression assessed perioperative characteristics associated with DGE. Sensitivity analyses stratified patients into negligible/low (FRS ≤2) or intermediate/high (FRS ≥3) cohorts based on their risk for clinically relevant POPF (CR-POPF). RESULTS: DGE was present in 15.5% of the overall cohort (N = 2,197/14,181), in 16.3% (N = 948/5,799) of the PPPD group, and in 14.9% (N = 1,249/8,382) of the classic PD group; 6.4% of patients (N = 903/14,181) were in the negligible/low-risk and 93.6% (N = 13,278) were in the intermediate/high-risk CR-POPF subgroups. In adjusted analysis of the overall cohort, patients who underwent PPPD were more likely to develop DGE (odds ratio [OR] 1.1, p = 0.02). In the negligible/low-risk CR-POPF subgroup, there was no association between DGE and PPPD (OR 1.05, p = 0.82). In the intermediate/high-risk CR-POPF subgroup, PPPD was significantly associated with DGE (OR 1.1, p = 0.04; Table). Table. - Predicting Delayed Gastric Emptying after Pylorus-Preserving vs Classic Pancreaticoduodenectomy, Stratified by Fistula Risk Score Surgical approach, pylorus preserving vs classic pancreatoduodenectomy Risk of clinically relevant- postoperative pancreatic fistula Adjusted odds ratio* 95% CI p Value Overall 1.11 1.01–1.22 0.02 Negligible/low risk 1.05 0.69–1.60 0.82 Intermediate/high risk 1.11 1.01–1.22 0.04 *Adjusted for age, sex, race, ASA class, history of comorbidities (eg smoking, hypertension, diabetes, blood disorder, weight loss, jaundice), preoperative stent placement, preoperative chemotherapy/radiation therapy, drain placement, pancreas gland texture, and duct size. CONCLUSION: Pylorus preservation in PD may have greater odds for developing DGE, driven by an increased association in patients who are at intermediate/high risk for CR-POPF. Use of the FRS for intraoperative decision-making regarding management of the pylorus may help minimize postoperative morbidity.

Characterization of Laryngotracheal Fractures and Repairs: A TQIP Study

Laryngotracheal trauma is poorly studied and associated with serious morbidity and mortality. This study reports features associated with laryngotracheal fractures, and factors associated with laryngeal fracture repair. Retrospective database study SETTING: American College of Surgeons Trauma Quality Improvement Program (ACS-TQIP®) METHODS: ACS-TQIP® 2014-2015 participant user data files were queried for laryngotracheal fractures using the International Classification of Diseases (ICD) 9th edition encodings. Demographic, diagnostic and procedure characteristics were analyzed with univariate chi-squared analysis and multivariate logistic regression. We extracted 635 cases of laryngotracheal injury, with a median Injury Severity Score of 16 (IQR: 10 - 25). Most were caused unintentionally (65.7%), followed by assault (28.8%). Blunt trauma (79.5%) was more common than penetrating trauma (20.0%). These trends were upheld in the subgroup of repaired fractures, which made up 12.6% (80/635) of cases. The median length of hospital stay was 6 days (IQR: 3 - 13) in all fractures and 10 days (IQR: 6 - 14) in the subgroup of repaired fractures, while the median length of ICU stay was 4 days (IQR: 2 - 9) in all fractures and 4.5 (IQR: 6 - 14.3) in the subgroup of repaired fractures. Cut/pierce injuries (OR: 4.7, P < 0.001) and ISS (OR: 0.97, pP=0.026) significantly affected rate of laryngeal fracture repair. Laryngotracheal fractures are uncommon but serious injuries. Our results show that penetrating causes of injuries have the shortest time to repair, and that a higher ISS score is negatively associated with repair.

Risk factors for early morbidity and mortality following pancreatoduodenectomy with concomitant vascular reconstruction

BackgroundLocally advanced pancreatic tumors may require vascular reconstruction for complete resection. However, pancreatoduodenectomy with vascular resection (PDVR) remains a subject of debate due to increased complications. MethodsPatients were identified using the ACS NSQIP Participant User Data Files from 2014 to 2019. ResultsThe 30-day mortality rate was 2.7%; major complications occurred in 32.2%. There is an increasing trend of PDVR in patients requiring pancreatectomy. There were no significant differences in mortality between PDVR with vein, artery, or venous and arterial resections. High BMI and postoperative biliary stent were risk factors for early complications. High BMI and COPD increased risk of early mortality. Chemotherapy and chemoradiotherapy were negative predictors for early morbidities and mortality, respectively. ConclusionThis study identifies the predictors of early morbidity and mortality in PDVR. The results of this study may assist decision making in perioperative management to optimize overall survival and guide additional research.

5G based Blockchain network for authentic and ethical keyword search engine

The evolution of 4G telecommunication propagated various resource-crunched clients to experience rate-effective resources at ease. However, it extends its underlying centralised architecture, which arouses various challenges correlated with network data availability, network information protection, and operational infrastructure charges. With the recent revolution of telecommunication, 5G networks promised to provide credible schemes like the high quality of service, ultra-low latency, and much security over the pre-existing architecture. However, the deployment of end-to-end 5G network cutting-edge systems in the present heterogeneous world limits its core idea of extensive data privacy, native interoperability, risk-free interference, and radio spectrum sharing. Perhaps, to achieve its true capability, improved versions of blockchain technology could be aligned to strengthen various real-time complex applications at a flourishing rate. One of the multiplexed real-time enterprise applications is a keyword search engine where the integrity of user data files and keyword searches are bound to come under cyber hackers. On the one hand, it was found that when a 5G-based blockchain emulated network gets deployed with intact encryption techniques, the entire system facilitates to give reliable, efficient, and risk-free keyword search over variegated 5G network data and its complex computational calculations. Consequently, the use of blockchain-based decentralised cloud orchestration scheme at various levels enabled the architecture to remain incorruptible and protects all the confidential files and keywords in a fully controlled file access environment. The results of the simulation kernel shows that proposed architecture which, when combined with blockchain-based decentralised cloud orchestration network system, justify all the essential characteristics and effectuates the optimal use of 5G network sharing by each network entity.

Secure fine-grained friend-making scheme based on hierarchical management in mobile social networks

With the rapid development of mobile social networks (MSNs) and smart mobile devices, mobile users can easily make new social interactions with others via their smartphones. Unfortunately, users enjoy these conveniences at the cost of revealing their personal data. The inevitable release of information conflicts with increasing privacy concerns. To address this problem, we propose a hierarchical management scheme for friend matching using attributes, which aims to facilitate secure friend discovery in MSNs. The scheme involves the establishment of several attribute centers, which perform fine-grained management based on various user attributes. The user attributes are used to generate attribute sub-keys. After meeting the conditions set by the friend-making initiator, the friend-making requester combines the sub-keys into a complete decryption key and decrypts the user data file in the friend-making center. By introducing hierarchical and sorting management of attribute sub-keys, we prevent the crypto key disclosure and single point failure, which usually happens because single-authority management centers are vulnerable to attack. The security and performance of this system were analyzed and evaluated via simulations, and the results indicate that the proposed scheme is CPA-safe.

Robotic pancreaticoduodenectomy decreases the risk of clinically relevant post-operative pancreatic fistula: a propensity score matched NSQIP analysis

BackgroundA single-institution study demonstrated robotic pancreaticoduodenectomy (RPD) was protective against clinically-relevant postoperative pancreatic fistula (CR-POPF) compared to open pancreaticoduodenectomy (OPD). We sought to compare the national rate of CR-POPF by approach. MethodsProcedure-targeted pancreatectomy Participant User Data File was queried from 2014 to 2017 for all patients undergoing pancreaticoduodenectomy. A modified fistula risk score was calculated and patients were stratified into risk categories. Multivariate logistic regression and propensity score matching was used. ResultsThe rate of CR-POPF (15.6% vs. 11.9%; p = 0.026) was higher in OPD compared to RPD. On subgroup analysis, OPD had higher CR-POPF in high risk patients (32.9% vs. 19.4%; p = 0.007). On multivariable analysis OPD was a predictor of increased CR-POPF (Odds Ratio [OR] = 1.61 [1.15–2.25]; p = 0.005). Other operative factors associated with increased CR-POPF included soft pancreatic texture (OR = 2.65 [2.27–3.09]; p < 0.001) and concomitant visceral resection (OR = 1.41 [1.03–1.93]; p = 0.031). Increased duct size (reference <3 mm) was predictive of decreased CR-POPF: 3–6 mm (OR = 0.70 [0.61–0.81]; p < 0.001) and ≥6 mm (OR = 0.47 [0.37–0.60]; p < 0.001). Following propensity score matching, RPD continued to be protective against the occurrence of CR-POPF (OR = 1.54 [1.09–2.17]; p = 0.013). ConclusionsThis is the largest multicenter study to evaluate the impact of RPD on POPF. It suggests that RPD can be protective against POPF, especially for high risk patients.

Outcomes after Open Lower Extremity Revascularization in Patients with Critical Limb Ischemia

For decades, open intervention was the treatment of choice in patients requiring lower extremity revascularization. In the endovascular era, however, open and endovascular revascularization are options. The implications of prior revascularization on the outcomes for subsequent revascularization are not known. In the present study, we evaluated 30-day outcomes after open lower extremity revascularization for critical limb ischemia (CLI) in those who had previous interventions. The 2012-2017 open lower extremity bypass Participant User Data Files from the National Surgical Quality Improvement Program were used to identify a cohort of patients with CLI. Patients whose operation was considered emergent were excluded from the analysis. Patients were stratified on whether they had a previous open or endovascular intervention or undergoing a primary revascularization. The primary outcome measure was 30-day major adverse limb events (MALEs). Secondary outcomes included major adverse cardiac events (MACEs) and wound complications. A total of 12,668 patients met study criteria with 59.6% (n=7,549) undergoing a primary open revascularization, 22.4% (n=2,839) having a prior endovascular intervention, and 18.0% (n=2,280) having a prior open revascularization. There were notable differences in the baseline characteristics between the 3 groups. In addition, there were differences in the reason for intervention (rest pain versus tissue loss), type of revascularization, and type of conduit used between the 3 groups. After adjustment, a prior open revascularization was significantly associated with 30-day MALE when compared with a primary revascularization (adjusted odds ratio, 1.69; 95% confidence interval, 1.47-1.94; P<0.001) and prior endovascular intervention (adjusted odds ratio, 1.76; 95% confidence interval, 1.46-2.12; P<0.001). There were no differences in outcomes between primary revascularization and prior endovascular patients. There were no differences between MACEs or wound complications between the 3 groups. A prior endovascular intervention does not seem to accrue any additional short-term risk when compared with primary revascularization, suggesting an endovascular-first approach may be a safe strategy in patients with CLI. However, a prior open intervention is significantly associated with 30-day MALE in patients undergoing redo open revascularization, which may be related to the rapid decline in patients once they have exhausted their best open revascularization option.

PhantomFS: File-Based Deception Technology for Thwarting Malicious Users

File-based deception technologies can be used as an additional security barrier when adversaries have successfully gained access to a host evading intrusion detection systems. Adversaries are detected if they access fake files. Though previous works have mainly focused on using user data files as decoys, this concept can be applied to system files. If so, it is expected to be effective in detecting malicious users because it is very difficult to commit an attack without accessing a single system file. However, it may suffer from excessive false alarms by legitimate system services such as file indexing and searching. Legitimate users may also access fake files by mistake. This paper addresses this issue by introducing a hidden interface. Legitimate users and applications access files through the hidden interface which does not show fake files. The hidden interface can also be utilized to hide sensitive files by hiding them from the regular interface. By experiments, we demonstrate the proposed technique incurs negligible performance overhead, and it is an effective countermeasure to various attack scenarios and practical in that it does not generate false alarms for legitimate applications and users.

Quality of MBSAQIP data: bad luck, or lack of QA plan?

National clinical registries are commonly used in clinical research, quality improvement, and health policy. However, little is known about methodological challenges associated with these registry analyses that could limit their impact and compromise patient safety. This study examined the quality of Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MSBASQIP) data to assess its usability potential and improve data collection methodologies. We developed a single flat file (n = 168,093) using five subsets (Main, BMI, Readmission, Reoperation, and Intervention) of the 2015 MBSAQIP Participant User Data File (PUF). Logic and validity tests included (1) individual profiles of patient's body mass index (BMI) changes over time, (2) individual patient care pathways, and (3) correlation analysis between variable pairs associated with the same clinical encounters. 8888 (5.3%) patients did not have postoperative weight/BMI data; 20% of patients had different units for preoperative and postoperative weights. Postoperative weight measurements ranged between - 71 and 132% of preoperative weight. There were 325 (3.7%) hospital readmissions reported on the day of or day after MBS. The self-reporting of "emergency" vs. "planned" interventions did not correlate with the type of procedure and its indication. Up to 20% of data could potentially be unused for analysis due to data quality issues. Our analysis revealed various data quality issues in the 2015 MBSAQIP PUF related to completeness, accuracy, and consistency. Since information on where the surgery was performed is lacking, it is not possible to conclude whether these issues represent data errors, patient outliers, or inappropriate care. Including automated data checks and biomedical informatics oversight, standardized coding for complications, additional de-identified facility and provider information, and training/mentorship opportunities in data informatics for all researchers who get access to the data have been shown to be effective in improving data quality and minimizing patient safety concerns.

A multi-agent system approach based on cryptographic algorithm for securing communications and protecting stored data in the cloud-computing environment

The cloud computing has been envisioned as the next generation architecture of information technology enterprise. The Internet is indispensable in present days to provide and maintain the data. Such applications can be used by the end-user via the cloud communications without any configuration. Moreover, the user's data files can be accessed from any other computer using the Internet services. The security goal is to save data from threat and vulnerability which is handled by various approaches. The data should be encrypted prior to be transmitted and stored. We aim to propose a solution such that we will encrypt the whole data along with the cryptographic key. This contribution provides a new architecture that combines, obfuscation technique, hybrid encryption algorithms and the homomorphic encryption approaches. The proposed security architecture based on multi-agent system for cloud computing communications and storage environment that takes into account the most known security gaps.

A multi-agent system approach based on cryptographic algorithm for securing communications and protecting stored data in the cloud-computing environment

The cloud computing has been envisioned as the next generation architecture of information technology enterprise. The Internet is indispensable in present days to provide and maintain the data. Such applications can be used by the end-user via the cloud communications without any configuration. Moreover, the user's data files can be accessed from any other computer using the Internet services. The security goal is to save data from threat and vulnerability which is handled by various approaches. The data should be encrypted prior to be transmitted and stored. We aim to propose a solution such that we will encrypt the whole data along with the cryptographic key. This contribution provides a new architecture that combines, obfuscation technique, hybrid encryption algorithms and the homomorphic encryption approaches. The proposed security architecture based on multi-agent system for cloud computing communications and storage environment that takes into account the most known security gaps.

A lightweight hybrid encryption technique to secure IoT data transmission

Internet of Things(IOT) is the rising innovation without bounds is required to associate billions of devices. IoT is the future where many low power resources and constrained devices are connected by means of the internet for communication, compute process and take actions in the communication network. The increased number of communication is relied upon to produce heaps of information and the security of information can be a threat resulting a secure solution for communication is necessitates among heterogenous devices. Focus of the work is to provide confidentiality, authentication and integrity of data in transit between IoT edge devices and back-end systems. This paper proposes a lightweight hybrid encryption system using ECDH key exchange mechanism for generating keys and establishing connection, digital signature for authentication, thereafter AES algorithm for encryption and decryption of user data file. The proposed combination is referred to as “three way secured data encryption mechanism” which interpret all the 3 protection schemes of authentication, info security and verification with the characteristics of lower calculation cost and faster speed makes it robust for hackers to crack the security system, thereby protective data in transmission.

Privacy Leaks through Data Hijacking Attack on Mobile Systems

To persistently eavesdrop on the mobile devices, attackers may obtain the elevated privilege and inject malicious modules into the user devices. Unfortunately, the attackers may not be able to obtain the privilege for a long period of time since the exploitable vulnerabilities may be fixed or the malware may be removed. In this paper, we propose a new data hijacking attack for the mobile apps. By employing the proposed method, the attackers are only required to obtain the root privilege of the user devices once, and they can persistently eavesdrop without any change to the original device. Specifically, we design a new approach to construct a shadow system by hijacking user data files. In the shadow system, attackers possess the identical abilities to the victims. For instance, if a victim has logged into the email app, the attacker can also access the email server in the shadow system without authentication in a long period of time. Without reauthentication of the app, it is difficult for victims to notice the intrusion since the whole eavesdropping is performed on other devices (rather than the user devices). In our experiments, we evaluate the effectiveness of the proposed attack and the result demonstrates that even the Android apps released by the top developers cannot resist this attack. Finally, we discuss some approaches to defend the proposed attack.

De-Identified Personal Health Care System Using Hadoop

Hadoop technology plays a vital role in improving the quality of healthcare by delivering right information to right people at right time and reduces its cost and time. Most properly health care functions like admission, discharge, and transfer patient data maintained in Computer based Patient Records (CPR), Personal Health Information (PHI), and Electronic Health Records (EHR). The use of medical Big Data is increasingly popular in health care services and clinical research. The biggest challenges in health care centers are the huge amount of data flows into the systems daily. Crunching this Big Data and de-identifying it in a traditional data mining tools had problems. Therefore to provide solution to the de-identifying personal health information, Map Reduce application uses jar files which contain a combination of MR code and PIG queries. This application also uses advanced mechanism of using UDF (User Data File) which is used to protect the health care dataset. De-identified personal health care system is using Map Reduce, Pig Queries which are needed to be executed on the health care dataset. The application input dataset that contains the information of patients and de-identifies their personal health care. De-identification using Hadoop is also suitable for social and demographic data.

A Method for Estimating the Risk of Surgical Site Infection in Patients With Abdominal Colorectal Procedures

Surgical site infection is one of the most common and significant morbidities following colon and rectal surgery, representing a marker of institutional quality. Various measures have been implemented to lower its incidence. However, the level of incidence remains unacceptable in many reports. This study addresses whether surgical site infections can be accurately predicted in an outpatient clinical setting among patients undergoing elective colon and rectal surgery. This investigation was designed as a retrospective cohort study with the use of logistic regression modeling. Data for this study were extracted from the American College of Surgeons National Surgical Quality Improvement Program Participant user data file. Patients undergoing elective intraabdominal colorectal surgery during 2009 were included. The primary outcome measured was the probability of 30-day surgical site infection (superficial and deep incisional). A total of 18,403 records for patients with colorectal surgery were identified. Superficial incisional surgical site infections were identified in 1447 records (7.86%). Deep incisional surgical site infections were identified in 278 records (1.51%). Body mass index, preoperative hematocrit, open approach, ASA classification level, smoking, alcohol use, functional status before surgery, and age more than 75 years were identified as likely independent predictors of deep and superficial surgical site infections. Multivariable logistic regression analysis was used to develop a series of predictive models. Reduced versions of the models were then developed that included only highly statistically significant predictors of infection in the corresponding full models (age, alcohol abuse, ASA classification, stoma closure, open approach, BMI, and hematocrit). Nomograms representing the final reduced model equations are presented. This study was limited by the use of an administrative database and its retrospective design. Surgical site infection is common morbidity following colon and rectal surgery. Nomograms using key patient characteristics can be used to accurately calculate a patients' risk of surgical site infection. This tool could be applied in the clinical setting to prospectively identify patients at highest risk of surgical site infection.

Is the Abdominal Repair of Rectal Prolapse Safer than Perineal Repair in the Highest Risk Patients? An NSQIP Analysis

Although the perineal approach in the surgical management of rectal prolapse has a higher recurrence, it is the accepted approach for higher-risk patients because of its lower morbidity. The aim of this study was to determine outcomes of abdominal versus perineal approaches to rectal prolapse repair. DESIGN SETTINGS: A retrospective study was performed comparing outcomes of patients undergoing different types of surgical approaches (open abdominal, laparoscopic, perineal) for rectal prolapse. The American College of Surgeons National Surgical Quality Improvement Participant User Data Files (2008-2009) were queried for patients undergoing adult, elective procedures for rectal prolapse. Univariate analysis and multivariate logistic regression were performed to look at age, ASA classification, procedure type, and resultant mortality rate. One thousand four hundred sixty-nine patients meeting our criteria were identified. Older patients (age>80) and higher-risk patients (ASA classifications 3 and 4) were significantly associated with the selection of the perineal approach. The overall mortality rate was 0.5%. The mortality rate for all perineal procedures was 0.9% in comparison with 0.13% for all abdominal operations (p = 0.033). The mortality rate for the highest-risk groups (ASA 3 and 4) for perineal procedures was 1.3% in comparison with 0.35% in the abdominal procedure group; the relative risk for mortality was 4 times greater in the perineal procedure group than in the abdominal procedure group. The retrospective design and standardized outcomes measured use administrative-level data and prevent the assessment of procedure-specific outcomes. Hospital mortality for the surgical repair of rectal prolapse is uncommon. The decision to choose the abdominal approach for the repair of rectal prolapse may not be as prohibitive as previously thought for higher-risk patients. Because of the broad range of functionality within each ASA classification, the operation offered should always be individualized, and patient selection is the most important factor.

Preoperative Inpatient Hospitalization and Risk of Perioperative Infection Following Elective Vascular Procedures

Health care-associated infections are not uncommon after elective vascular surgery and can negatively impact mortality rates and hospital resource utilization. Identification of modifiable risk factors for perioperative infection is critical for efforts aimed toward reducing their incidence. We evaluated the associations between preoperative inpatient hospitalization and perioperative surgical site infection (SSI), pneumonia, and urinary tract infection (UTI) following elective vascular surgery procedures. Vascular procedures were identified from the 2005 to 2008 American College of Surgeons National Safety Quality Improvement Participant User Data File by using primary Current Procedural Terminology (CPT) codes. Perioperative infections were evaluated as outcomes based on three categories: SSI, pneumonia, and UTI. Patients admitted ≥1 day before operation were considered inpatients before surgery. Associations between preoperative inpatient hospitalization and perioperative SSI, pneumonia, and UTI were evaluated using the Cochran-Armitage trend test and multivariable logistic regression. In total 40,669 elective vascular procedures were identified, of which 7,514 (18.5%) were preoperative inpatients. Patients with preoperative inpatient hospitalization had a greater frequency of age >80 years and dependent functional status and also had higher rates of several comorbid conditions, including congestive heart failure, severe chronic obstructive pulmonary disease, >10% weight loss over the past 6 months, history of bleeding disorder, and current smoker within 1 year, than patients admitted on the same day of their procedure. The overall rates of SSI, pneumonia, and UTI were 3.2%, 1.9%, and 1.4%, respectively. Patients with preoperative inpatient hospitalization had higher 30-day incidence of SSI (4.5 vs. 2.9%), pneumonia (3.1 vs. 1.6%), and UTI (2.3 vs. 1.2%). In multivariable models including preoperative risk factors, preoperative inpatient hospitalization was associated with increased 30-day risk of SSI (odds ratio [OR], 1.21; 95% confidence interval [CI]: 1.06-1.39; p = 0.0066), pneumonia (OR, 1.64; 95% CI: 1.39-1.94; p < 0.0001), and UTI (OR, 1.46; 95% CI: 1.20-1.77; p < 0.0001). Preoperative inpatient hospitalization is associated with higher rates of perioperative SSI, pneumonia, and UTI in patients undergoing elective vascular surgery procedures. Avoidance of unnecessary preoperative hospitalization has potential to reduce rates of perioperative infection, but additional research is needed to develop evidence-based management strategies when hospitalization before elective procedures is necessary.