New non-glycosidic diterpenes from the leaves of Stevia rebaudiana

Six new labdane-type, non-glycosidic diterpenes, sterebins I-N (1-6), were isolated from the leaves of Stevia rebaudiana. Their structures, analogous to those of the previously described sterebins A-H, were elucidated on the basis of spectroscopic and chemical studies.     

Classifying highly imbalanced ICU data

Highly imbalanced data sets are those where the class of interest is rare. In this paper, we compare the performance of several common data mining methods, logistic regression, discriminant analysis, Classification and Regression Tree (CART) models, C5, and Support Vector Machines (SVM) in predicting the discharge status (alive or deceased, with “deceased” being the class of interest) of patients from an Intensive Care Unit (ICU). Using a variety of misclassification cost ratio (MCR) values and using specificity, recall, precision, the F-measure, and confusion entropy (CEN) as criteria for evaluating each method’s performance, C5 and SVM performed better than the other methods. At a MCR of 100, C5 had the highest recall and SVM the highest specificity and lowest CEN. We also used Hand’s measure to compare the five methods. According to Hand’s measure, logistic regression performed the best. This article makes several contributions. We show how the use of MCR for analyzing imbalanced medical data significantly improves the method’s classification performance. We also found that the F-measure and precision did not improve as the MCR was increased.     

Lessons Learned from the Reimbursement Profile of a Mature Private Medical Toxicology Practice: Office-Based Practice Pays

We previously reported the financial data for the first 5 years of one of the author’s medical toxicology practice. The practice has matured; changes have been made. The practice is increasing its focus on office-based encounters and reducing hospital-based acute care encounters. We report the reimbursement rates and other financial metrics of the current practice. Financial records from October 2009 through September 2013 were reviewed. This is a period of 4 fiscal years and represents the currently available financial data. Charges, payments, and reimbursement rates were recorded according to the type and setting of the medical toxicology encounter: forensic consultations, outpatient clinic encounters, nonpsychiatric inpatient consultations, emergency department (ED) consultations, and inpatient psychiatric consultations. All patients were seen regardless of ability to pay or insurance status. The number of billed Current Procedural Terminology (CPT) codes for office-based encounters increased over the study period; the number of billed CPT codes for inpatient and ED consultations reduced. Office-based encounters demonstrate a higher reimbursement rate and higher payments. In the fiscal year (FY) of 2012, office-based revenue exceeded hospital-based acute care revenue by over $140,000 despite a higher number of billed CPT encounters in acute care settings, and outpatient payments were 2.39 times higher than inpatient, inpatient psychiatry, observation unit, and ED payments combined. The average payment per CPT code was higher for outpatient clinic encounters than inpatient encounters for each fiscal year studied. There was an overall reduction in CPT billing volume between FY 2010 and FY 2013. Despite this, there was an increase in total practice revenue. There was no change in payor mix, practice logistics, or billing/collection service company. In this medical toxicology practice, office-based encounters demonstrate higher reimbursement rates and overall payments compared to inpatient and ED consultations. While consistent with our previous studies, these differences have been accentuated. This study demonstrates the results of changes to the practice—reduced inpatient/ED consultations and increased outpatient encounters. These practice changes resulted in higher overall revenue despite a lower patient volume. In this analysis, the office-based practice of medical toxicology has higher reimbursement rates, nearly 2.5 times higher, when compared to hospital-based acute care consultations.