Introducción: Actualmente, los traumatismos son considerados la sexta causa de mortalidad y la quinta causa de discapacidad en todos los grupos etarios. Uno de los factores más importantes en la supervivencia de un paciente traumatizado es el tiempo de injuria. Objetivo: Estimar la asociación entre el tiempo de injuria y el nivel de estatus funcional al alta en pacientes adultos con trauma enrolados en el ensayo CRASH-2 durante los años 2005-2010. Métodos: Estudio de tipo cohorte retrospectiva que corresponde a un análisis secundario de la base de datos del ensayo experimental CRASH-2. Se calculó el riesgo relativo (RR) del tiempo de injuria que se define como el intervalo de tiempo que inicia desde el momento del accidente hasta la el arribo al hospital y estatus funcional mediante un modelo lineal generalizado de la familia Poisson, link log con varianza robusta con un intervalo de confianza al 95% ajustado por edad, sexo, tipo de injuria, accidente cerebro vascular (ACV), traumatismo encéfalo craneano (TEC) y eventos vasooclusivos. Resultados: Se analizó la información de 16,950 pacientes para este estudio. El 66.97% de los pacientes tuvieron un tiempo no prolongado (≤ 3 horas) y el 76.77% presentaron un estatus funcional independiente al alta. Encontramos que los pacientes que tuvieron un tiempo de injuria prolongado tienen un 11.00% más riesgo de presentar un estatus funcional dependiente en comparación a los pacientes con tiempo de injuria no prolongado. Conclusión: Nuestro estudio apoya el rápido transporte de pacientes con trauma ante la relación entre un tiempo de injuria prolongado y el desarrollo de un estatus funcional dependiente. / Introduction: Currently, trauma is considered the sixth global cause of mortality and fifth cause of disability in all age groups. . One of the most important factors in the survival of an injured patient is the injury time. Objective: To estimate the association between injury time and functional status at discharge in adult trauma patients enrolled in the CRASH-2 trial during the years 2005-2010. Methods: Retrospective cohort study corresponding to a secondary analysis of the CRASH-2 experimental trial database. The relative risk (RR) of time of injury (defined as the time interval from the time of the injury to hospital arrival) and functional status was calculated using a generalized linear model of the Poisson family, link log with robust variance with a 95% confidence interval adjusted for age, sex, type of injury, stroke, traumatic brain injury (TBI) and vaso-oclusive events. Results: Data from 16,950 patients were analyzed for this study. The 66.97% of the patients had a non-prolonged injury time (≤ 3 hours) and 76.77% presented an independent functional status at discharge. We found that patients who had a prolonged injury time had a 11.00% higher risk of presenting a dependent functional status compared to patients with a non-prolonged injury time. Other factors associated with dependent functional status are age, type of injury, stroke, TBI, among others. Conclusions: Our study concludes that a prolonged injury time increases the risk of developing a dependent functional status and due to this result, we encourage the rapid transportation of trauma patients to reduce the risk of dependent functional status. / Tesis

Propósito: Evaluar el valor del Vesikari Scoring System (VSS) como herramienta diagnóstica en la predicción de patógenos en niños con gastroenteritis aguda. Métodos: En un estudio retrospectivo, se analizó 247 historias clínicas y registros laboratoriales del Hospital de Emergencias Pediátricas (Lima, Perú), utilizando el diagnóstico de CIE-10 A00-A009 (enfermedades intestinales infecciosas). Se dividió según los patógenos detectados: no específico, viral y bacteriana. Se detectaron las bacterianas por coprocultivo y las virales por inmunoanálisis. Los casos no específicos tenían ambos resultados negativos o no hubo pruebas laboratoriales. Se ha calculado la sensibilidad, especificidad, valores predictivos negativos (VPN) y positivos (VPP), índice de probabilidad (LR) y el área bajo la curva (ROC). Resultado: El área bajo la curva ROC del VSS no fue significativo para determinar la etiología bacteriana ni viral. En el punto de corte de 9 en VSS, se analizó VPP (18.29%) y VPN (89.47%). Los leucocitos en heces tuvieron un área bajo la curva ROC de 0.8831(IC95% 0,79-0,96 y p=0.04) para etiología bacteriana, con una sensibilidad de 80.95%, especificidad de 88.24% y LR- de 0.22. Los leucocitos en heces con un punto de corte de ≥20, tuvo una precisión aceptable para diagnosticar gastroenteritis bacteriana. La prueba de moco en heces tuvo una sensibilidad de 83.33%, especificidad de 82.35% y VPP de 95.89%. Conclusión: El VSS no es una herramienta adecuada para determinar etiología de gastroenteritis viral y bacteriana. Sin embargo, se ha determinado que los leucocitos en heces con un punto de corte de ≥20 leucocitos por campo y moco en heces permite identificar la gastroenteritis aguda bacteriana. / Purpose: To evaluate the Vesikari Scoring System (VSS) as a valuable diagnostic tool for predicting pathogens in children with acute gastroenteritis. Methods: In this retrospective study were analyzed 247 clinical and laboratory records of the Pediatric Emergency Hospital (Lima, Peru), with the diagnosis of ICD-10 A00-A009 (Intestinal Infectious diseases). According to the pathogens detected were divided into groups: non-specific, viral, and bacterial. Bacteria were detected by stool culture, viral pathogens by immune analysis. The non-specific group had negative on both tests, or they did not perform. We calculated sensitivity, specificity, negative and positive predictive values, negative and positive likelihood ratios, and receiver operating characteristic curves.  Results: The area under the ROC curve of VSS was not significant for viral and bacterial etiology. The cut-off point of 9 in VSS was calculated by analyzing PPV (18,29%) and NPV (89,47%). The fecal leukocyte had a ROC of 0.8831 (IC95% 0.79-0.96 and p=0.04) for bacterial group, with a sensibility of 80,95%, specificity of 88,24% and LR- of 0,22. At a cut-off point of ≥20 fecal leukocytes was an acceptable diagnostic accuracy for bacterial gastroenteritis. The stool mucus for the bacterial group had a sensibility of 83,33%, a specificity of 82,35%, and a PPV of 95,89%. Conclusion: VSS is not an adequate diagnostic tool to differentiate viral from bacterial etiology. Nevertheless, we determine that a test of fecal leukocytes, with a cut-off point of ≥20 leukocytes per field and mucus in stools, allow us to identify the bacterial etiology of gastroenteritis. / Tesis

Managed care plans purport to improve the health of their members with chronic diseases. How has the growing adoption of Medicare Advantage (MA), the managed care program for Medicare beneficiaries, affected the progression of chronic disease? The literature is rich with articles focusing on managed care organizations' impacts on quality of care, access, patient satisfaction, and costs. However, few studies have analyzed these impacts with respect to market penetration of Medicare managed care. The objective of this research has been to analyze the relationships between the market penetration of MA plans and the progression of chronic diseases among Medicare beneficiaries. The Chronic Disease Severity Index scale (CDSI) was constructed to represent beneficiaries' overall chronic disease states for survey or claims-based data, when more direct clinical measures of disease progression are not available. Using the CDSI on the MEPS survey dataset from AHRQ, we sought to assess the impacts of MA market penetration and other covariates on the overall chronic disease state of Medicare beneficiaries from 2004 through 2008. Though the model explains much of the variation in CDSI change, the author expected the multilevel model would show that MA penetration explains a significant level of variation in CDSI change. However, this hypothesis was not substantiated, and the findings suggest that unmeasured factors may be contributing to additional unexplained heterogeneity. Policymakers should explore opportunities to refine the current MA program. The MA program costs the federal government more than the Traditional Fee-for-Service Medicare program, and there is no definitive evidence that outcomes differ. Within both programs, there is opportunity to experiment with different models of payment, healthcare service delivery and care coordination. The Patient Protection and Affordable Care Act (ACA) contains provisions for innovative demonstration projects in delivery and payment. The effectiveness of these ACA initiatives must be monitored, both for impacts on health outcomes and for economic effects. This research can inform future approaches to outcomes assessment using the CDSI, and multilevel modeling methodologies similar to those employed here. Firms offering MA health plans would be prudent to proactively demonstrate their value to beneficiaries and taxpayers. They should explore means of better monitoring and reporting the longitudinal outcomes of their enrolled beneficiaries. Demonstrating that they can bring value in terms of improved health outcomes will help insure their long-term survival, both in the marketplace and in the political arena. / Graduation date: 2012