The model of hierarchical complexity (mhc) is a mathematical model based on the “Theory of Measurement” that has gone through a number of iterations as a measurement system (Commons, Goodheart, Pekker, et al., 2005; Commons & Pekker, 2008; Commons & Richards, 1984a, 1984b; Commons, Trudeau, Stein, et all, 1998). It sets forth the measurement system by which actions are put into a hierarchical order and each order is assigned an ordinal number. In this paper, the components of the model will be described: actions and tasks, measurement and I operations, and the axioms, followed by an articulation of emerging properties from axioms, and then a description I of orders of hierarchical complexity of tasks. These are a reworked smaller set of axioms, which are more measurement-theoretical in nature. They also parallel the informal conditions underlying the kind of complexity that the mhc entails.

The aim of this study was to evaluate the impact on predoctoral dental students of an experiential and self‐learning pedagogical approach to evidence‐based decision making. Dental students at one U.S. dental school in 2014 and 2015 participated in an evidence‐based decision making course that consisted of minimal lecturing, learning through assigned readings and open‐book online quizzes, and individual assignments to reach an evidence‐based decision on a clinically relevant question. Before and after the course, each cohort completed a validated survey assessing students' knowledge, attitudes, access of evidence, and confidence related to evidence‐based practice. In 2014, of 43 students enrolled in the course, all 43 (100%) completed the pre‐course survey, and 33 (77%) completed the post‐course survey. In 2015, of 35 students enrolled in the course, all 35 (100%) completed the pre‐course survey, and 34 (97%) completed the post‐course survey. Of those, the identifier codes for 23 students in 2014 and 25 students in 2015 matched for the pre‐course and post‐course surveys, allowing direct comparisons. Both cohorts of students showed a significant increase in knowledge regarding critical appraisal of the literature from the pre‐course survey results to after the course (p<0.001). Students' reported frequency of accessing evidence from various sources also significantly increased from before to after the course for both cohorts (p<0.01). Students' confidence in evaluating various aspects of a published research report also increased significantly from before to after the course for both cohorts (p<0.001). However, no consistent change was found in students' attitudes about evidence‐based practice. In this study, an experiential and self‐learning approach to teaching evidence‐based decision making in the classroom appeared to be successful in improving students' knowledge, use of evidence, and confidence in critical appraisal skills, though it did not have a consistent impact on their attitudes about evidence‐based practice.

Background To evaluate the differences in treatment modality and outcomes between male and female patients with laryngeal squamous cell carcinoma (SCC) in the United States. Methods Data were extracted from the Surveillance, Epidemiology, and End Results Database for patients with laryngeal SCC (2004‐2013). Overall survival (OS), disease specific survival (DSS), and multivariate analyses were conducted. Results Among women, supraglottic cancers were the most prevalent (61.2%); whereas the majority of men developed glottic cancers (64.2%; P < .001). Women with T4 disease were more likely to undergo primary radiation (56.8% vs 45.3%; P < .001) and less likely to undergo open surgery were than men (37.1% vs 48.2%; P < .001). Women had significantly better OS in glottic and supraglottic cancers, and comparable survival in subglottic cancer. Sex remained an independent prognostic factor for both DSS and OS. Conclusion Sex is an independent prognostic factor for DSS and OS in patients with laryngeal SCC.

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