Potential patient harms from misinterpretation of publically reported surgical outcomes.

OBJECTIVE: To determine how the general public interprets surgical complication rates presented from a publicly available online surgical-rating website. SUBJECTS AND METHODS: An in-person electronic survey was administered at the local State Fair to a convenience sample. Participants were presented with a representative output from an online surgeon-rating website and were asked to choose from three statistically equivalent surgeons for a hypothetical medical decision. We then suggested that their insurance company would only cover one surgeon and probed their willingness to pay to switch surgeons for a small chance of lowering the risk of a complication (0.7%, 95% confidence interval [CI] -8.1% to 9.5%, P = 0.9). We quantified the characteristics of those willing to switch, the degree of misinterpretation, and the subsequent potential patient harms. RESULTS: There were 343 completed responses. When presented with a hypothetical healthcare decision, most participants (n = 209, 61%) said they were willing to pay out-of-pocket expenses to switch to a statistically equivalent surgeon. Those who were willing to pay to switch surgeons were more likely to be older (odds ratio [OR] 1.02, 95% CI 1.01-1.03), poorer (OR 1.81, 95% CI 1.07-3.11), previously had cancer (OR 5.9, 95% CI 1.9-25), and misinterpreted the data (OR 3.03, 95% CI 1.87-4.96). Those who were willing to pay out-of-pocket expenses were more inaccurate in their estimation of surgeon complication rates (mean estimate 34.0% vs 8.9%, P < 0.001, correct rate = 3.6%), and on average were willing to pay $6 494 (95% CI 4 108-8 880). CONCLUSION: Understanding of a publicly reported surgical-complication website is often prone to misinterpretation by the general population and may lead to patient harm from a financial aspect.

Comparison of Temperature-Index Snowmelt Models for Use within an Operational Water Quality Model.

The accurate prediction of snowmelt runoff is a critical component of integrated hydrological and water quality models in regions where snowfall constitutes a significant portion of the annual precipitation. In cold regions, the accumulation of a snowpack and the subsequent spring snowmelt generally constitutes a major proportion of the annual water yield. Furthermore, the snowmelt runoff transports significant quantities of sediment and nutrients to receiving streams and strongly influences downstream water quality. Temperature-index models are commonly used in operational hydrological and water quality models to predict snowmelt runoff. Due to their simplicity, computational efficiency, low data requirements, and ability to consistently achieve good results, numerous temperature-index models of varying complexity have been developed in the past few decades. The objective of this study was to determine how temperature-index models of varying complexity would affect the performance of the water quality model SWAT (a modified version of SWAT that was developed for watersheds dominated by boreal forest) for predicting runoff. Temperature-index models used by several operational hydrological models were incorporated into SWAT. Model performance was tested on five watersheds on the Canadian Boreal Plain whose hydrologic response is dominated by snowmelt runoff. The results of this study indicate that simpler temperature-index models can perform as well as more complex temperature-index models for predicting runoff from the study watersheds. The outcome of this study has important implications because the incorporation of simpler temperature-index snowmelt models into hydrological and water quality models can lead to a reduction in the number of parameters that need to be optimized without sacrificing predictive accuracy.

A piezoelectric ultrasonic linear micromotor using a slotted stator.

A novel ultrasonic micro linear motor that uses 1st longitudinal and 2nd bending modes, derived from a bartype stator with a rectangular slot cut through the stator length, has been proposed and designed for end-effect devices of microrobotics and bio-medical applications. The slot structure plays an important role in the motor design, and can be used not only to tune the resonance frequency of the two vibration modes but also to reduce the undesirable longitudinal coupling displacement caused by bending vibration at the end of the stator. By using finite element analysis, the optimal slot dimension to improve the driving tip motion was determined, resulting in the improvement of the motor performance. The trial linear motor, with a weight of 1.6 g, gave a maximum driving velocity of 1.12 m/s and a maximum driving force of 3.4 N. A maximum mechanical output power of 1.1 W was obtained at force of 1.63 N and velocity of 0.68 m/s. The output mechanical power per unit weight was 688 W/kg.

A study on axial and torsional resonant mode matching for a mechanical system with complex nonlinear geometries.

Making use of mechanical resonance has many benefits for the design of microscale devices. A key to successfully incorporating this phenomenon in the design of a device is to understand how the resonant frequencies of interest are affected by changes to the geometric parameters of the design. For simple geometric shapes, this is quite easy, but for complex nonlinear designs, it becomes significantly more complex. In this paper, two novel modeling techniques are demonstrated to extract the axial and torsional resonant frequencies of a complex nonlinear geometry. The first decomposes the complex geometry into easy to model components, while the second uses scaling techniques combined with the finite element method. Both models overcome problems associated with using current analytical methods as design tools, and enable a full investigation of how changes in the geometric parameters affect the resonant frequencies of interest. The benefit of such models is then demonstrated through their use in the design of a prototype piezoelectric ultrasonic resonant micromotor which has improved performance characteristics over previous prototypes.

Interexaminer reliability of the deltoid and psoas muscle test.

OBJECTIVE: To determine if 2 practitioners of differing skill levels could reliably agree on the presence of a weak or strong deltoid or psoas muscle. STUDY DESIGN: Interexaminer reliability study of 2 common muscle tests. MAIN OUTCOME MEASURES: Cohen kappa (unweighted) scores, observer agreement, and 95% confidence intervals (CIs). RESULTS: The results showed that an experienced and a novice practitioner have good agreement when using repeated muscle test procedures on the deltoid ( kappa 0.62) and the psoas ( kappa 0.67). CONCLUSIONS: The manual muscle test procedures using the anterior deltoid or psoas showed good interexaminer reliability when used by an experienced and a novice user. These techniques may be used between practitioners in multidoctor assessment/management programs.

Chronobiotic activity of N-[2-(2,7-dimethoxyfluoren-9-yl)ethyl]-propanamide. Synthesis and melatonergic pharmacology of fluoren-9-ylethyl amides.

A series of fluoren-9-yl ethyl amides (2) were synthesized and evaluated for human melatonin MT(1) and MT(2) receptor binding. N-[2-(2,7-dimethoxyfluoren-9-yl)ethyl]propanamide (2b) was selected and evaluated in functional assays measuring intrinsic activity at the human MT(1) and MT(2) receptors and demonstrated full agonism at both receptors. The chronobiotic properties of 2b were demonstrated in both acute and chronic rat models where 2b produced an acute phase advance of 32 min at 1mg/kg and chronically entrained free-running rats with a mean effective dose of 0.23 mg/kg. Compound 2b is significantly less efficacious than melatonin in constricting human coronary artery.