The costs and value of modelling-based design in healthcare delivery: five case studies from the US.

In the nineties and noughties, Hollocks surveyed the use of Discrete Event Simulation (DES) in industry and listed (although he could not quantify the value of) benefits. This paper explores how DES is now used to design healthcare facilities and services, developing a value-for-money case with a protocol on collecting information. We present a set of five DES case studies from the US care system and, following Hollocks, focus on modelling as part of a rigorous design process, capturing as many of the benefits as possible. Healthcare offers the possibility of ascribing value to health improvement, but in these cases it is primarily the operational benefits of a better service that are reported and monetarised. By estimated the cost of modelling and the value of the operation gains, this paper contributes significantly to the literature. We conclude with a protocol for collecting information and a discussion of methods by which different types of benefit may be captured.

Elimination of Emergency Department Medication Errors Due To Estimated Weights.

From 7/2014 through 6/2015, 10 emergency department (ED) medication dosing errors were reported through the electronic incident reporting system of an urban academic medical center. Analysis of these medication errors identified inaccurate estimated weight on patients as the root cause. The goal of this project was to reduce weight-based dosing medication errors due to inaccurate estimated weights on patients presenting to the ED. Chart review revealed that 13.8% of estimated weights documented on admitted ED patients varied more than 10% from subsequent actual admission weights recorded. A random sample of 100 charts containing estimated weights revealed 2 previously unreported significant medication dosage errors (.02 significant error rate). Key improvements included removing barriers to weighing ED patients, storytelling to engage staff and change culture, and removal of the estimated weight documentation field from the ED electronic health record (EHR) forms. With these improvements estimated weights on ED patients, and the resulting medication errors, were eliminated.

Simulated radioscapholunate fusion alters carpal kinematics while preserving dart-thrower's motion.

PURPOSE: Midcarpal degeneration is well documented after radioscapholunate fusion. This study tested the hypothesis that radioscapholunate fusion alters the kinematic behavior of the remaining lunotriquetral and midcarpal joints, with specific focus on the dart-thrower's motion. METHODS: Simulated radioscapholunate fusions were performed on 6 cadaveric wrists in an anatomically neutral posture. Two 0.060-in. carbon fiber pins were placed from proximal to distal across the radiolunate and radioscaphoid joints, respectively. The wrists were passively positioned in a custom jig toward a full range of motion along the orthogonal axes as well as oblique motions, with additional intermediate positions along the dart-thrower's path. Using a computed tomography-based markerless bone registration technique, each carpal bone's three-dimensional rotation was defined as a function of wrist flexion/extension from the pinned neutral position. Kinematic data was analyzed against data collected on the same wrist prior to fixation using hierarchical linear regression analysis and paired Student's t-tests. RESULTS: After simulated fusion, wrist motion was restricted to an average flexion-extension arc of 48 degrees , reduced from 77 degrees , and radial-ulnar deviation arc of 19 degrees , reduced from 33 degrees . The remaining motion was maximally preserved along the dart-thrower's path from radial-extension toward ulnar-flexion. The simulated fusion significantly increased rotation through the scaphotrapezial joint, scaphocapitate joint, triquetrohamate joint, and lunotriquetral joint. For example, in the pinned wrist, the rotation of the hamate relative to the triquetrum increased 85%. Therefore, during every 10 degrees of total wrist motion, the hamate rotated an average of nearly 8 degrees relative to the triquetrum after pinning versus 4 degrees in the normal state. CONCLUSIONS: Simulated radioscapholunate fusion altered midcarpal and lunotriquetral kinematics. The increased rotations across these remaining joints provide one potential explanation for midcarpal degeneration after radioscapholunate fusion. Additionally, this fusion model confirms the dart-thrower's hypothesis, as wrist motion after simulated radioscapholunate fusion was primarily preserved from radial-extension toward ulnar-flexion.