Geometric stopping of a random walk and its applications to valuing equity-linked death benefits

We study discrete-time models in which death benefits can depend on a stock price index, the logarithm of which is modeled as a random walk. Examples of such benefit payments include put and call options, barrier options, and lookback options. Because the distribution of the curtate-future-lifetime can be approximated by a linear combination of geometric distributions, it suffices to consider curtate-future-lifetimes with a geometric distribution. In binomial and trinomial tree models, closed-form expressions for the expectations of the discounted benefit payment are obtained for a series of options. They are based on results concerning geometric stopping of a random walk, in particular also on a version of the Wiener-Hopf factorization.

Early versus delayed application of Thomas splints in patients with isolated femur shaft fractures: The benefits quantified.

AIMS: To investigate and quantify the clinical benefits of early versus delayed application of Thomas splints in patients with isolated femur shaft fractures. MATERIALS AND METHODS: Level IV retrospective clinical and radiological analysis of patients presenting from January to December 2012 at a Level 1 Trauma Unit. All skeletally mature patients with isolated femur shaft fractures independently of their mechanism of injury were included. Exclusion criteria were: ipsilateral fracture of the lower limb, neck and supracondylar femur fractures, periprosthetic and incomplete fractures. Their clinical records were analysed for blood transfusion requirements, pulmonary complications, surgery time, duration of hospital stay and analgesic requirements. RESULTS: A total of 106 patients met our inclusion criteria. There were 74 males and 32 females. Fifty seven (54%) patients were in the 'early splinted' group and 49 patients (46%) were in the 'delayed splinted' group (P>0.05). The need for blood transfusion was significantly reduced in the 'early splinted' group (P=0.04). There was a significantly higher rate of pulmonary complications in the 'delayed splinted' group (P=0.008). All other parameters were similar between the two groups. CONCLUSION: The early application of Thomas splints for isolated femur fractures in non-polytraumatised patients has a clinically and statistically significant benefit of reducing the need for blood transfusions and the incidence of pulmonary complications.

Simulated Patient as Co-facilitators: Benefits and Challenges of the Interprofessional Team OSCE (Submission #9350).

Hypothesis: The quality of care for chronic patients depends on the collaborative skills of the healthcare providers.1,2 The literature lacks reports of the use of simulation to teach collaborative skills in non-acute care settings. We posit that simulation offers benefits for supporting the development of collaborative practice in non-acute settings. We explored the benefits and challenges of using an Interprofessional Team - Objective Structured Clinical Examination (IT-OSCE) as a formative assessment tool. IT-OSCE is an intervention which involves an interprofessional team of trainees interacting with a simulated patient (SP) enabling them to practice collaborative skills in non-acute care settings.5 A simulated patient are people trained to portray patients in a simulated scenario for educational purposes.6,7 Since interprofessional education (IPE) ultimately aims to provide collaborative patient-centered care.8,9 We sought to promote patient-centeredness in the learning process. Methods: The IT-OSCE was conducted with four trios of students from different professions. The debriefing was co-facilitated by the SP with a faculty. The participants were final-year students in nursing, physiotherapy and medicine. Our research question focused on the introduction of co-facilitated (SP and faculty) debriefing after an IT-OSCE: 1) What are the benefits and challenges of involving the SP during the debriefing? and 2) To evaluate the IT-OSCE, an exploratory case study was used to provide fine grained data 10, 11. Three focus groups were conducted - two with students (n=6; n=5), one with SPs (n=3) and one with faculty (n=4). Audiotapes were transcribed for thematic analysis performed by three researchers, who found a consensus on the final set of themes. Results: The thematic analysis showed little differentiation between SPs, student and faculty perspectives. The analysis of transcripts revealed more particularly, that the SP's co-facilitation during the debriefing of an IT-OSCE proved to be feasible. It was appreciated by all the participants and appeared to value and to promote patient-centeredness in the learning process. The main challenge consisted in SPs feedback, more particularly in how they could report accurate observations to a students' group rather than individual students. Conclusion: In conclusion, SP methodology using an IT-OSCE seems to be a useful and promising way to train collaborative skills, aligning IPE, simulation-based team training in a non-acute care setting and patient-centeredness. We acknowledge the limitations of the study, especially the small sample and consider the exploration of SP-based IPE in non-acute care settings as strength. Future studies could consider the preparation of SPs and faculty as co-facilitators. References: 1. Borrill CS, Carletta J, Carter AJ, et al. The effectiveness of health care teams in the National Health Service. Aston centre for Health Service Organisational Research. 2001. 2. Reeves S, Lewin S, Espin S, Zwarenstein M. Interprofessional teamwork for health and social care. Oxford: Wiley-Blackwell; 2010. 3. Issenberg S, McGaghie WC, Petrusa ER, Gordon DL, Scalese RJ. Features and uses of high-fidelity medical simulations that lead to effective learning - a BEME systematic review. Medical Teacher. 2005;27(1):10-28. 4. McGaghie W, Petrusa ER, Gordon DL, Scalese RJ. A critical review of simulation-based medical education research: 2003-2009. Medical Education. 2010;44(1):50-63. 5. Simmons B, Egan-Lee E, Wagner SJ, Esdaile M, Baker L, Reeves S. Assessment of interprofessional learning: the design of an interprofessional objective structured clinical examination (iOSCE) approach. Journal of Interprofessional Care. 2011;25(1):73-74. 6. Nestel D, Layat Burn C, Pritchard SA, Glastonbury R, Tabak D. The use of simulated patients in medical education: Guide Supplement 42.1 - Viewpoint. Medical teacher. 2011;33(12):1027-1029. Disclosures: None (C) 2014 by Lippincott Williams & Wilkins, Inc.