Dataset Information

Prospective Validation of the Iowa Rectal Surgery Risk Calculator.

ABSTRACT: BACKGROUND:The Iowa Rectal Surgery Risk Calculator estimates risk for proctectomy procedures. The Iowa Calculator performed well on NSQIP 2010-2011 training and 2005-2009 validation datasets, but was not prospectively validated and did not include low anterior resections. This study sought to demonstrate validity on new independent data, to update the calculator to include low anterior resection, and to compare performance to other risk assessment tools. METHODS:Non-emergent ACS-NSQIP proctectomy and low anterior resection data from 2010 to 2015 (n =?65,683) were included. The Iowa Calculator generated risk estimates for 30-day morbidity using 2012-2015 data. An Updated Calculator used 2010-2011 training data to include low anterior resection, with validation on 2012-2015 data. NSQIP data provided NSQIP Morbidity Model predictions and a custom web-script collected ACS-NSQIP Online Surgical Risk Calculator predictions for all patients. RESULTS:Proctectomy morbidity (not including low anterior resection) decreased from 40.4% in 2010-2011 to 37.0% in 2012-2015. Low anterior resection had lower morbidity (22.4% in 2012-15). The Iowa Calculator demonstrated good discrimination and calibration using 2012-2015 data (C-statistic 0.676, deviance +?9.2%). After including low anterior resection, the Updated Iowa Calculator performed well during training (c-statistic 0.696, deviance 0%) and validation (C-statistic 0.706, deviance +?7.9%). The Updated Iowa Calculator had significantly better discrimination and calibration than morbidity predictions from the ACS Online Calculator (C-statistic 0.693, P

SUBMITTER: Sherman SK

PROVIDER: S-EPMC6035768 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature

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Prospective Validation of the Iowa Rectal Surgery Risk Calculator.

Sherman Scott K SK Hrabe Jennifer E JE Hrabe Jennifer E JE Huang Emily E Cromwell John W JW Byrn John C JC

Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract 20180423 7

<h4>Background</h4>The Iowa Rectal Surgery Risk Calculator estimates risk for proctectomy procedures. The Iowa Calculator performed well on NSQIP 2010-2011 training and 2005-2009 validation datasets, but was not prospectively validated and did not include low anterior resections. This study sought to demonstrate validity on new independent data, to update the calculator to include low anterior resection, and to compare performance to other risk assessment tools.<h4>Methods</h4>Non-emergent ACS-N ...[more]

PMID: 29687422

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Project description:ObjectiveTo independently validate a published risk-calculator for adverse perioperative outcomes in patients with epithelial ovarian cancer undergoing debulking surgery at a high-volume surgical center.MethodsUsing our institution's curated prospective ovarian cancer database, we identified patients with epithelial ovarian cancer who underwent a debulking procedure from 7/2015 to 5/2019, to be used as the validation cohort. Variables used in the published nomogram were collected. These included American Society of Anesthesiology classification, preoperative albumin, history of bleeding disorder, presence of ascites on preoperative imaging, designation of elective or emergent surgery, age of the patient, and a procedure score. Patients were included if they had information available for all the variables used in the nomogram, and 30-day follow-up within our institution. The primary outcome was Clavien-Dindo Class IV with specific conditions (postoperative sepsis, septic shock, cardiac arrest, myocardial infarction, pulmonary embolism, ventilation >48 h, or unplanned intubation) and 30-day mortality. The combination of these endpoints is called the combined complication rate.ResultsA total of 700 patients who underwent debulking surgery for epithelial ovarian cancer during the timeframe met inclusion criteria. The combined complication rate was 11.7%; 9.9% of patients were readmitted; 2.7% required reoperation. Sepsis was the most common primary endpoint complication (4.4%), followed by septic shock (1.4%). There was no 30-day mortality in our cohort. The nomogram performed well, with a c index of 0.715 (95% CI 0.66-0.768), which was comparable to the published nomogram.ConclusionsWe independently validated a complication nomogram at a high-volume surgical center. This nomogram performs well at predicting a lower likelihood of serious postoperative complications. An enhanced nomogram would help identify patients at higher risk for serious complications.

Project description:BackgroundGuidelines recommend extended chemoprophylaxis for venous thromboembolism in high-risk patients having operations for inflammatory bowel disease. Quantifying patients' risk of venous thromboembolism, however, remains challenging. We sought (1) to identify factors associated with postdischarge venous thromboembolism in patients undergoing colorectal resection for inflammatory bowel disease and (2) to develop a postdischarge venous thromboembolism risk calculator to guide prescribing of extended chemoprophylaxis.MethodsPatients who underwent an operation for inflammatory bowel disease from 2012 to 2018 were identified from the American College of Surgeons National Surgical Quality Improvement Program for colectomy and proctectomy procedure targeted modules. Postdischarge venous thromboembolism included pulmonary embolism or deep vein thrombosis diagnosed after discharge from the index hospitalization. Multivariable logistic regression estimated the association of patient/operative factors with postdischarge venous thromboembolism. A postdischarge venous thromboembolism risk calculator was subsequently constructed.ResultsOf 18,990 patients, 199 (1.1%) developed a postdischarge venous thromboembolism within the first 30 postoperative days. Preoperative factors associated with postdischarge venous thromboembolism included body mass index (1.9% with body mass index ≥35 vs 0.8% with body mass index 18.5-24.9; odds ratio 2.34 [95% confidence interval 1.49-3.67]), steroid use (1.3% vs 0.7%; odds ratio 1.91 [95% confidence interval 1.37-2.66]), and ulcerative colitis (1.5% vs 0.8% with Crohn's disease; odds ratio 1.76 [95% confidence interval 1.32-2.34]). Minimally invasive surgery was associated with postdischarge venous thromboembolism (1.2% vs 0.9% with open; odds ratio 1.42 [95% confidence interval 1.05-1.92]), as was anastomotic leak (2.8% vs 1.0%; odds ratio 2.24 [95% confidence interval 1.31-3.83]) and ileus (2.1% vs 0.9%; odds ratio 2.60 [95% confidence interval 1.91-3.54]). The predicted probability of postdischarge venous thromboembolism ranged from 0.2% to 14.3% based on individual risk factors.ConclusionPreoperative, intraoperative, and postoperative factors are associated with postdischarge venous thromboembolism after an operation for inflammatory bowel disease. A postdischarge venous thromboembolism risk calculator was developed which can be used to tailor extended venous thromboembolism chemoprophylaxis by individual risk.

Project description:BackgroundExternal validation of risk calculators (RCs) is necessary to determine their clinical applicability beyond the setting in which these were developed.ObjectiveTo assess the performance of the Rotterdam Prostate Cancer RC (RPCRC) and the Prostate Biopsy Collaborative Group RC (PBCG-RC).Design setting and participantsWe used data from the prospective, population-based STHLM3 screening study, performed in 2012-2015. Participants with prostate-specific antigen ≥3 ng/ml who underwent systematic prostate biopsies were included.Outcome measurements and statistical analysisProbabilities for clinically significant prostate cancer (csPCa), defined as International Society of Urological Pathology grade ≥2, were calculated for each participant. External validity was assessed by calibration, discrimination, and clinical usefulness for both original and recalibrated models.Results and limitationsOut of 5841 men, 1054 (18%) had csPCa. Distribution of risk predictions differed between RCs; median risks for csPCa using the RPCRC and PBCG-RC were 3.3% (interquartile range [IQR] 2.1-7.1%) and 20% (IQR 15-28%), respectively. The correlation between RC risk estimates on individual level was moderate (Spearman's r = 0.55). Using the RPCRC's recommended risk threshold of ≥4% for finding csPCa, 36% of participants would get concordant biopsy recommendations. At 10% risk cut-off, RCs agreed in 23% of cases. Both RCs showed good discrimination, with areas under the curves for the RPCRC of 0.74 (95% confidence interval [CI] 0.72-0.76) and the PBCG-RC of 0.70 (95% CI 0.68-0.72). Calibration was adequate using the PBCG-RC (calibration slope: 1.13 [95% CI 1.03-1.23]), but the RPCRC underestimated the risk of csPCa (calibration slope: 0.73 [0.68-0.79]). The PBCG-RC showed a net benefit in a decision curve analysis, whereas the RPCRC showed no net benefit at clinically relevant risk threshold levels. Recalibration improved clinical benefit, and differences between RCs decreased.ConclusionsAssessment of calibration is essential to ensure the clinical value of risk prediction tools. The PBCG-RC provided clinical benefit in its current version online. On the contrary, the RPCRC cannot be recommended in this setting.Patient summaryPredicting the probability of finding prostate cancer on biopsy differed between two assessed risk calculators. After recalibration, the agreement of the models improved, and both were shown to be clinically useful.

Project description:Study designA retrospective study at a single academic institution.ObjectiveThe purpose of this study is to utilize machine learning to predict hospital length of stay (LOS) and discharge disposition following adult elective spine surgery, and to compare performance metrics of machine learning models to the American College of Surgeon's National Surgical Quality Improvement Program's (ACS NSQIP) prediction calculator.Summary of background dataA total of 3678 adult patients undergoing elective spine surgery between 2014 and 2019, acquired from the electronic health record.MethodsPatients were divided into three stratified cohorts: cervical degenerative, lumbar degenerative, and adult spinal deformity groups. Predictive variables included demographics, body mass index, surgical region, surgical invasiveness, surgical approach, and comorbidities. Regression, classification trees, and least absolute shrinkage and selection operator (LASSO) were used to build predictive models. Validation of the models was conducted on 16% of patients (N=587), using area under the receiver operator curve (AUROC), sensitivity, specificity, and correlation. Patient data were manually entered into the ACS NSQIP online risk calculator to compare performance. Outcome variables were discharge disposition (home vs. rehabilitation) and LOS (days).ResultsOf 3678 patients analyzed, 51.4% were male (n=1890) and 48.6% were female (n=1788). The average LOS was 3.66 days. In all, 78% were discharged home and 22% discharged to rehabilitation. Compared with NSQIP (Pearson R2 =0.16), the predictions of poisson regression ( R2 =0.29) and LASSO ( R2 =0.29) models were significantly more correlated with observed LOS ( P =0.025 and 0.004, respectively). Of the models generated to predict discharge location, logistic regression yielded an AUROC of 0.79, which was statistically equivalent to the AUROC of 0.75 for NSQIP ( P =0.135).ConclusionThe predictive models developed in this study can enable accurate preoperative estimation of LOS and risk of rehabilitation discharge for adult patients undergoing elective spine surgery. The demonstrated models exhibited better performance than NSQIP for prediction of LOS and equivalent performance to NSQIP for prediction of discharge location.

Project description:BackgroundN-nitroso compounds (NOC) formed endogenously after nitrate/nitrite ingestion and disinfection by-products (DBPs) are suspected colorectal carcinogens, but epidemiologic evidence of these associations is limited.ObjectivesWe investigated the relationship between drinking water exposures and incident colorectal cancers in a cohort of postmenopausal women.MethodsUsing historical nitrate-nitrogen (NO3-N) measurements and estimates of total trihalomethanes (TTHM), the sum of 5 or 6 haloacetic acids (HAAs), and individual DBPs in public water supplies (PWS), we computed average exposures and years of exposure above one-half the U.S. maximum contaminant level (>1/2-MCL; >5 mg/L NO3-N and >40 μg/L TTHM). Nitrate/nitrite intakes from dietary sources were estimated using a food frequency questionnaire. We estimated hazard ratios (HR) and 95% confidence intervals (CI) from Cox regression models. We assessed NO3-N interactions with DBPs and with factors influencing endogenous NOC formation.ResultsWe identified 624 colon and 158 rectal cancers (1986-2010) among 15,910 women reporting PWS use >10 years. Ingestion of NO3-N from drinking water was not associated with risk. Colon cancer risks were non-significantly associated with the average TTHM levels >17.7 μg/L (HRQ5vsQ1 = 1.13, CI = 0.89-1.44; ptrend = 0.11) and were elevated for any duration of exposure >1/2-MCL. Rectal cancer risks were associated with the highest TTHM levels (HRQ5vsQ1 = 1.71, CI = 1.00-2.92; ptrend = 0.22) but not with years >1/2-MCL. Bromodichloromethane (HRQ4vsQ1 = 1.89, CI = 1.17-3.00; ptrend = 0.09) and trichloroacetic acid (HRQ4vsQ1 = 1.92, CI = 1.20-3.09; ptrend = 0.18) levels were also associated with risk of rectal cancer. We found no evidence of interaction between TTHM and NO3-N on the risk of either cancer. Dietary analyses yielded a positive colon cancer association with red meat, but not with processed meat intake or estimated nitrate/nitrite from specific dietary sources.ConclusionsOur results suggest that exposure to TTHM in drinking water is associated with increased risk of rectal cancer. Positive findings for individual THMs and HAAs for both colon and rectal cancers require replication in other studies. We found no associations for nitrate overall or in subgroups with presumed higher NOC exposure.

Project description:The circumferential resection margin is the primary determinant of local recurrence and a major factor in survival in rectal cancer. Neither chemotherapy nor chemoradiation compensates for a margin positive for cancer.To identify treatment-related factors associated with hospital margin-positive resection and to develop a tool that could be used by individual hospitals to assess their outcomes based on their unique mix of patient and tumor characteristics.Retrospective review of the National Cancer Data Base, 1998-2007.Community and academic/research hospitals.Individuals with histologically confirmed localized rectal/rectosigmoid adenocarcinoma.All individuals underwent radical resection for rectal cancer with or without neoadjuvant therapy.Rate of margin positivity determined and adjusted for patient- and tumor-related factors to calculate expected margin positivity per hospital. An observed to expected ratio was calculated based on patient- and tumor-related factors to identify treatment-associated variation.The overall margin-positive resection rate was 5.2%. Patients with margins positive for cancer were more likely to be older, male, and African American; not have private insurance; and have their cancer diagnosed later in the study period. Associated tumor-related factors include rectal location, higher American Joint Committee on Cancer stage, signet/mucinous histology, and poor/undifferentiated grade. Among hospitals that were significantly low outliers, 47% were comprehensive community hospitals, and 43.9% were academic/research hospitals; of those that were significantly high outliers, 52.3% were comprehensive community hospitals, and 17.8% were academic/research hospitals. High-volume centers made up 80% of significantly low outlier hospitals and 17% of significantly high outlier hospitals. The rates of chemotherapy and radiation were similar, but low outlier hospitals gave more neoadjuvant radiation (26.3% vs 17%).After adjustment for patient- and tumor-related factors, we identified both low and high outlier hospitals for margin positivity at resection, as well as potentially modifiable risk factors. The nomogram created in this model allows for the evaluation of observed and expected event rates for individual hospitals, providing a hospital self-assessment tool for identifying targets for improvement.

Dataset Information

Prospective Validation of the Iowa Rectal Surgery Risk Calculator.

Publications

Prospective Validation of the Iowa Rectal Surgery Risk Calculator.

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