The study of stress is limited in professional nursing, but it is nearly non-existent in professional military nursing. The purpose of this study was to explore the relationships among psychological, environmental, biological and demographic factors of stress in new Army nurses during the Army Medical Department’s 8-week Officer Basic Leadership Course (OBLC). Using a descriptive prospective, correlational repeated measures design, 33 study participants completed two psychological stress measures (Perceived Stress Scale [PSS] and the Impact of Event Scale – Revised[IES-R]), an environmental measure (Life Experiences Survey [LES]), a biologic measure (salivary cortisol) and a demographic questionnaire at three different time points during OBLC: at the beginning of OBLC, during the field training exercise and at the end of OBLC. The majority of participants were single, Caucasian females under 30 years of age with no RN experience and no deployment experience. No significant gender differences were detected among study variables. A simple (single-group) repeated measures analysis of the PSS scores, IES-R scores, and salivary cortisol was conducted using the LES score as a covariate. While the PSS scores and salivary cortisol levels did not change significantly over time, the IES-R score did change significantly over time (p = 0.001). The environmental factor (LES score) was not significant as a covariate in any of the three models. The unique baseline findings in this study may provide a springboard for further studies in stress particularly with military nurses who will eventually be deployed and experience a variety of stressful events. Longitudinal research could yield important predictive information related to how the stress response evolves over the course of one’s military career which may include frequent deployments to the combat zone.

The purpose of this study was to determine if the four assessments for entrance into an academic middle school gifted English program were accurately predicting success, as measured by students’ grades each nine-week grading period. Some students were dismissed from the program each year because they could not maintain the required minimum average of 80%. The four entrance assessments evaluated were the Cognitive Abilities Test (CogAT), Naglieri Nonverbal Ability Test (NNAT), STEP Writing test, and the Iowa Test of Basic Skills: Reading (ITBS). The sample consisted of 150 sixth, seventh, and eighth grade students studied longitudinally over the span of four years from a suburban middle school in a large Texas school district. Using correlation, logistic regression, and generalized linear regression models, the results showed that all the students selected to participate in the middle school gifted English program were statistically capable of success, whether they successfully remained in the program or not. Additionally, the results indicated that the two achievement tests (ITBS Reading and STEP Writing test) better predicted which students were successful, whereas the aptitude tests (CogAT and NNAT) did not. The achievement tests were determined to be better predictors of students’ success, as measured by grades, in this rigorous academic middle school gifted English program. Other findings include (a) students’ grades increased over time in the program, (b) females were predicted to earn about two point higher grades than males, and (c) the individual student was a significant predictor of success based on entrance scores. Finally, several recommendations were made for future research. These possibilities include repeating this study using standard scores for data analysis rather than the percentile scores that were available for this investigation. An additional recommendation is to investigate a possible replacement for the STEP Writing test, as it has not been nationally normed in decades. Another possibility would be to evaluate the curriculum and teacher effectiveness within the district using the NAGC (2010b) Pre-K-Grade 12 Gifted Programming Standards. A final potential study could implement specific interventions for use with students at-risk for underachievement to determine which strategies are most effective.

Auditory Steady-State Response (ASSR) is a promising tool for detecting hearing loss. In this project, we analyzed hearing threshold data obtained from two ASSR methods and a gold standard, pure tone audiometry, applied to both normal and hearing-impaired subjects. We constructed a repeated measures linear model to identify factors that show significant differences in the mean response. The analysis shows that there are significant differences due to hearing status (normal or impaired) and ASSR method, and that there is a significant interaction between hearing status and test signal frequency. The second task of this project was to predict the PTA threshold (gold standard) from the ASSR-A and ASSR-B thresholds separately at each frequency, in order to measure how accurate the ASSR measurements are and to obtain a ¡°correction function¡± to correct the bias in the ASSR measurements. We used two approaches. In the first, we modeled the relation of the PTA responses to the ASSR values for the two hearing status groups as a mixture model and tried two prediction methods. The mixture modeling was successful, but the predictions gave disappointing results. A second approach, using logistic regression to predict group membership based on ASSR value and then using those predictions to obtain a predictor of the PTA value, gave successful results.

Em muitos trabalhos científicos, é comum encontrar os dados estruturados de forma hierarquica, ou seja, os indivíduos em estudo estão agrupados em unidades de nível mais baixo, que por sua vez pertencem a unidades de um nível mais alto e assim sucessivamente. Na análise desse tipo de dados é importante levar em conta a estrutura hierarquica uma vez que, não faze-la, pode implicar na superestimação dos coecientes do modelo em estudo. Assim, para facilitar a análise de dados seguindo uma estrutura hierarquica, foram desenvolvidos os modelos multiníveis. Tais modelos levam em conta toda a variabilidade existente para os dados num mesmo nível como nos diferentes níveis da hierarquia. No caso da análise de dados de medidas repetidas no tempo, uma estrutura hierarquica em dois níveis pode ser considerada, organizando as ocasiões de medidas, no primeiro nível, para cada indivíduo no segundo nível. Neste trabalho, é feita uma abordagem dos modelos multiníveis para vários níveis da hierarquia bem como os métodos de estimação e teste dos parâmetros envolvidos no modelo. Como aplicação, foram analisados dados provenientes do Programa de Atenção ao Idoso (PAI), desenvolvido no ambulatório municipal Dr. Plinio do Prado Coutinho em Alfenas, M.G., em que foram observadas as variáveis Indice de Massa Corporea (imc) e Pressão Arterial dos idosos durante 22 meses. Também, foram analisados dados referentes ao teor de proteína no leite de 79 vacas australianas, coletados durante 19 semanas após o parto e submetidas a três dietas (Diggle et al., 1994). Para os dados do "PAI", foi possível verificar que as diferentes medidas de pressão arterial estão relacionadas positivamente com o imcao longo do tempo, independente de sexo, idade e estado civil. Já nos dados relativos ao teor de proteína no leite, notou-se uma redução do teor de proteína no leite ao longo do tempo, independente dos tratamentos aplicados. Foram utilizados os softwares MLwiN e SAS para a realização das análises. / It is common to and data structured in a hierarchical form in several scientific works, that is, the studied subjects are nested in the lowest level unites, that belong to the highest level unites, and so on. To analyze these sort of data it is important to take in account the hierarchical structure once, if does not do it, the coeficients can be overestimated in the studied model. Then, in order to become easier the data analysis according to the hierarchical structure, multilevel models were developed. Such models take into account all the existing variability for the data at the same level as well as in diferent levels of the hierarchy. In the case of repeated measure data, a two levels hierarchical structure can be considered, organizing the occasions at the first level for each subject at the second level. In this work, na approach of the multilevel models for several levels are made as well as the estimation methods and the tests for the involved parameters in the model. As an application, data from the Elderly Care Program (ECP), developed at outpatient clinic Dr. Plinio do Prado Coutinho at Alfenas, M.G., where the Body Mass Index and the Bloody Pressure were observed from elderly people for 22 months. Also, it was analyzed the milk protein content of 79 australian cows during 19 weeks after calving and subject to three diets (Diggle et al., 1994). For the data of the ECP it was possible to observe that the bloody pressure are positively related to the occasions, independently of sex, race and marital status. For the data form the milk protein content, a reduce in the content in the occasions even after the diets are included. MLwiN and SAS softwares were used to run the analysis.

Os modelos de transição de Markov constituem uma ferramenta de grande importância para diversas áreas do conhecimento quando são desenvolvidos estudos com medidas repetidas. Eles caracterizam-se por modelar a variável resposta ao longo do tempo condicionada a uma ou mais respostas anteriores, conhecidas como a história do processo. Além disso, é possível a inclusão de outras covariáveis. No caso das respostas binárias, pode-se construir uma matriz com as probabilidades de transição de um estado para outro. Neste trabalho, quatro abordagens diferentes de modelos de transição foram comparadas para avaliar qual estima melhor o efeito causal de tratamentos em um estudo experimental em que a variável resposta é um vetor binário medido ao longo do tempo. Estudos de simulação foram realizados levando em consideração experimentos balanceados com três tratamentos de natureza categórica. Para avaliar as estimativas foram utilizados o erro padrão, viés e percentual de cobertura dos intervalos de confiança. Os resultados mostraram que os modelos de transição marginalizados são mais indicados na situação em que um experimento é desenvolvido com um reduzido número de medidas repetidas. Como complementação, apresenta-se uma forma alternativa de realizar comparações múltiplas, uma vez que os pressupostos como normalidade, independência e homocedasticidade são violados impossibilitando o uso dos métodos tradicionais. Um experimento com dados reais no qual se registrou a presença de fungos (considerada como sucesso) em cultivos de citros e morango foi analisado por meio do modelo de transição apropriado. Para as comparações múltiplas, intervalos de confiança simultâneos foram construídos para o preditor linear e os resultados foram estendidos para a resposta média que neste caso são as probabilidades de sucesso. / The transition Markov models are a very important tool for several areas of knowledge when studies are developed with repeated measures. They are characterized by modeling the response variable over time conditional to the previous response which is known as the history. In addtion it is possible to include other covariates. In the case of binary responses, can be constructed a matrix of transition probabilities from one state to another. In this work, four different approaches to transition models were compared in order to assess which best estimates of the causal effect of treatments in an experimental studies where the outcome is a vector of binary response measured over time. Simulation study was held taking into account a balanced experiments with three treatments of categorical nature. To assess the best estimates standard error and bias, beyond the percentage of coverage were used. The results showed that the marginalized transition models are more appropriate in situation where an experiment is developed with a reduced number of repeated measurements. As complementation is presented an alternative way to perform multiple comparisons, since the assumptions as normality, independence and homoscedasticity are violated precluding the use of traditional methods. An experiment with real data where we recorded the presence of fungi (deemed successful) in citrus and strawberry crops was analyzed through the appropriate transition model. For multiple comparisons, simultaneous confidence intervals were constructed for the linear predictor and the results have been extended to the mean response in this case are the probabilities of success.

Ankle sprains are one of the most common musculoskeletal injuries. Physiotherapy treatment and advice to rest, use ice, use compression, and elevate the ankle (RICE advice) is believed to speed up the functional recovery and enhance healing associated with acute ankle sprains. However, there is limited evidence to support the efficacy of RICE treatment. This study investigated whether physiotherapy (including RICE advice) was as effective as RICE advice alone in improving the time to recovery in a clinical situation.The evidence for RICE advice was reviewed along with the different treatment modalities currently used by physiotherapists in New Zealand for acute ankle sprain. This review highlighted the low number and poor quality of studies investigating RICE and early intervention physiotherapy management for ankle sprains. RICE principals appear to be relatively inexpensive and somewhat effective for pain relief and may reduce further tissue damage in the acute stage of Grade I and II ankle sprains. Evidence extrapolated from studies investigating the use of post surgical ice appears to support the use of ice in the acute stage of an ankle sprain to minimise bleeding and oedema. The intermittent application of ice is more effective for pain relief in the acute phase than sustained icing. Physiotherapy interventions such as TENS for pain relief and bracing for the support of Grade II - III ankle sprains have been shown to be beneficial for pain relief in the acute phase. A need for further high quality, randomised controlled trials (RCT's) was identified.Subsequently a RCT was conducted with 28 participants to investigate the difference between (a) early intervention physiotherapy management combined with RICE advice, and (b) self management RICE advice without physiotherapy.Twenty eight individuals (males n = 22, females n = 6), between the ages of 16 and 40 with acute ankle sprains, who met the inclusion criteria, were approached by physiotherapists working on this project and invited to participate. Dependant variables were pain, function, swelling, compliance and medication use up to Day 11 post injury. Swelling, pain and function were measured over three assessments on Days 1, 3 and 11, using volumetric analysis, a visual analogue scale (VAS) and a functional question derived from a validated functional questionnaire respectively. Medication use and compliance were elicited from information gathered in a participant home diary. Both groups were similar on Day 1 in respect to their initial pain, swelling, the number of participants who were referred for X-rays, and the time taken to present to the physiotherapist. However the RICE group had significantly higher function scores (p = 0.042). The RICE group also had a significantly higher use of medication on Day 1 (p = 0.035) and Day 11 (p = 0.048). For both groups there was a statistically significant decrease in swelling (p = 0.003), pain scores (p = 0.000), and an increase in function scores (p = 0.000) in relation to time over the eleven days of assessment. The physiotherapy group had significantly improved function scores (p = 0.042) from Day 1 to Day 11 compared to the RICE group. There were no significant differences between groups for swelling, pain scores, and their first day of documented non-compliance. The within day range of error in the volumetric measurements was within 189.9 ml and 1.2 ml. Three trials were conducted per person within a Day session. The first volumetric analysis was significantly less than the subsequent two measurements (p = 0.040).It was concluded that, in the early stage of an ankle injury both physiotherapy and RICE, and RICE advice alone, resulted in significant improvements in swelling, pain and function. Early intervention physiotherapy was significantly better at improving the functional ability of participants by Day 11. Early intervention physiotherapy may also identify complications associated with ankle sprains.Despite its limitations this research could potentially lead to changes in the standard treatment protocols for soft tissue ankle injuries. Implementation of self management RICE by patients in the acute stage would initially reduce the cost of physiotherapy treatments, and may lead to equal improvements in pain and swelling outcomes. However, it appears that physiotherapy may lead to better functional outcomes which would reduce the costs associated with time off work, and rehabilitation. It is important to note that these findings are based on a small sample size and on Grade I or II ankle ligament sprains, and that treatment for more severe ankle injuries may be better with physiotherapy, or surgery, rather than self management RICE by patients. Findings contribute to the growing body of 'best practice' evidence for health practitioners. Keywords: Acute soft tissue injuries, ankle, sprain, early intervention, physiotherapy, RICE, volumetric measurement.

Axial rotation is regarded as an essential movement of the trunk that allows many individuals to participate in vocations, sports and activities of daily living. Unfortunately when the destabilising nature of rotation is combined with that of spinal flexion, the risk of injuring the spine can increase significantly. Few studies have investigated the potential benefits that maximizing trunk rotation has in certain vocation and sport-related arenas and none have looked at whether adopting certain spinal postures in the sagittal plane can maximise trunk rotation more than others. The aim of the study was to determine the effects of alterations of trunk inclination, spinal posture, pelvic fixation and turning direction on the active range of motion (ROM) of trunk rotation. Twenty healthy individuals participated in the main study. Retro-reflective markers were placed on key anatomical locations and used to track the movement of the thorax and pelvis during a series of repeated maximal trunk rotations in ten different spinal positions within the sagittal plane. Trunk kinematics and kinetics were recorded simultaneously using an optoelectronic motion analysis and force platform measuring system. A repeated-measures multiple analysis of variance (MANOVA) was used to test for the main effects of trunk inclination, spinal posture, fixation of pelvis and direction of turn on maximum active ROM of trunk rotation, maximum pelvic rotation and the anterior-posterior and lateral displacement of the centre of pressure (COP). To investigate test-retest reliability, ten participants were tested on two separate days. Repeatability for each outcome measure was investigated using interclass correlation coefficients (ICC) and Bland Altman graphs. The majority of subjects showed reasonable test-retest reliability for trunk rotation measures in each of the test positions, with ICC’s ranging between 0.562 – 0.731. Overall, trunk inclination (0°, 22.5°, 45°) forward in the sagittal plane had a significant effect on trunk and pelvic rotation (p<0.001) and lateral displacement of the COP (p<0.005) during trunk rotation. As trunk inclination increased from 0° to 45° there was an average increase in trunk rotation ROM of approximately 10 % (approximately 3.4°). Furthermore, increasing trunk inclination led to an increase in lateral displacement of the COP and a decrease in pelvic rotation. Spinal posture (neutral, flexed, extended) at a forward inclination of 45° had a significant effect on trunk rotation (p<0.01) and pelvic rotation (p<0.05), with a neutral spine averaging approximately 3 % (approximately 1.1°) more trunk rotation than a flexed or extended posture. The position and posture of the spine in the sagittal plane appears to have a significant influence on ranges of trunk rotation. The study suggests that rotating the trunk when adopting a neutral spine inclined to 45° will maximise range of trunk rotation and encourage a natural stabilisation of the lower body. This posture meets the unique set of biomechanical requirements for the sport of golf and may help to reduce the risk of injury in manual material handling tasks. Conversely, rotating the trunk whilst the thoracolumbar spine is flexed leads to a reduction in trunk rotation ROM, encourages greater pelvic and lower body rotation, reduces torque production of the trunk and may increase the risk of lower back injury. These findings have important implications in relation to the teaching of spinal position during vocations, sports and activities of daily living that seek to maximise trunk rotation.

Semiparametric regression has become very popular in the field of Statistics over the years. While on one hand more and more sophisticated models are being developed, on the other hand the resulting theory and estimation process has become more and more involved. The main problems that are addressed in this work are related to efficient inferential procedures in general semiparametric regression problems. We first discuss efficient estimation of population-level summaries in general semiparametric regression models. Here our focus is on estimating general population-level quantities that combine the parametric and nonparametric parts of the model (e.g., population mean, probabilities, etc.). We place this problem in a general context, provide a general kernel-based methodology, and derive the asymptotic distributions of estimates of these population-level quantities, showing that in many cases the estimates are semiparametric efficient. Next, motivated from the problem of testing for genetic effects on complex traits in the presence of gene-environment interaction, we consider developing score test in general semiparametric regression problems that involves Tukey style 1 d.f form of interaction between parametrically and non-parametrically modeled covariates. We develop adjusted score statistics which are unbiased and asymptotically efficient and can be performed using standard bandwidth selection methods. In addition, to over come the difficulty of solving functional equations, we give easy interpretations of the target functions, which in turn allow us to develop estimation procedures that can be easily implemented using standard computational methods. Finally, we take up the important problem of estimation in a general semiparametric regression model when covariates are measured with an additive measurement error structure having normally distributed measurement errors. In contrast to methods that require solving integral equation of dimension the size of the covariate measured with error, we propose methodology based on Monte Carlo corrected scores to estimate the model components and investigate the asymptotic behavior of the estimates. For each of the problems, we present simulation studies to observe the performance of the proposed inferential procedures. In addition, we apply our proposed methodology to analyze nontrivial real life data sets and present the results.

The current study aims to investigate empirically the main incentives for mandatory and voluntary risk reporting (MRR and VRR) across the USA, the UK and Germany, each of which has a unique approach towards risk reporting. While the UK approach encourages more voluntary risk reporting above imposing risk rules, the German approach formally requires firms to provide risk information in a certain place in their annual report narratives. The US approach is a compromise between these two approaches; it obligates and encourages firms to provide more information about their risks mandatorily and/or voluntarily, respectively. Investigating the incentives for risk reporting in such set of countries answers the calls of some prior research (e.g., Linsley and Shrives, 2006; Dobler, 2008; Dobler, Lajili and Zeghal, 2011) to deepen our understanding of what motivates firms to disclose their risks. To this end, computerised content analysis and multilevel analysis (MLA) on a large scale (compared with previous work e.g., Linsley and Shrives, 2005, 2006; Abraham and Cox, 2007) are utilised. The results are produced in four cumulative contexts through Chapters Six to Nine. These results are consistent with managers’ incentives theories (discussed in Chapter Two) and prior risk reporting literature (discussed in Chapter Three and Chapter Four). Based on 15 firms in each country during 2007 and 2008, multivariate analysis of variance (MANOVA) results reveal significant differences between a firm’s risk levels and its risk disclosure levels across the USA, the UK and Germany. The correlation results indicate that these differences are statistically correlated, supporting the main argument of the current study that differences in a firm’s risk levels should be reflected in their risk reporting practices (Chapter Six). Based on 1160 firm-years of non-financial firms of the FTSE all share index over 2005-2008, linear mixed model (LMM) results document that firms with higher levels of systematic and financing risks are likely to exhibit significantly higher levels of aggregated and voluntary risk reporting, whereas firms with high variability of stock returns or lower levels of liquidity are likely to exhibit significantly lower levels of aggregated and voluntary risk reporting. The current study also finds, however, that MRR is associated significantly and positively with firm size rather than with risk levels. The results also indicate that managers of firms exhibiting greater compliance with UK risk reporting regulations have greater incentives to disclose voluntary risk information (Chapter Seven). When the study extends the scope to the other two countries, different patterns of relations are found. Based on 1270, 1410 and 1005 firm-year observations over 2005 to 2009 in the USA, the UK and Germany, respectively, repeated measures multilevel analysis (RMMLA) results suggest that, in the USA, MRR is more sensitive to firm risk levels (total, systematic and liquidity risks) than is VRR, which is more correlated to other firm characteristics. The UK results suggest that VRR is more sensitive to firm risk levels (systematic and liquidity risks) than is MRR, which is dominated by firm size, among other firm characteristics. In Germany, however, both MRR and VRR are significantly related to risk levels (total, systematic, un-systematic, financing and liquidity risks) (Chapter Eight). Based on 3685 firm-year observations during the period between 2005 and 2009, and concerning both firm- and country-level analyses, repeated measures multilevel analysis (RMMLA) results support that variations in MRR can be attributed to differences in the legal systems (country characteristics) and in firm size (firm characteristics). The variations in VRR are more associated with firm characteristics, especially a firm’s risk levels across the USA, the UK and Germany (Chapter Nine). These results have many implications and support the respective regulatory approach adopted within each country by interpreting the extent to which either MRR or VRR is more or less sensitive to underlying risks.

Traffic-related injuries represent a global public health problem, and contribute largely to mortality and years lived with disability worldwide. Over the course of the last decades, improvements to road traffic safety and injury surveillance systems have resulted in a shift in focus from the prevention of motor vehicle accidents to the control of injury events involving vulnerable road users (VRUs), such as cyclists and moped riders. There have been calls for improvements to the evaluation of safety interventions due to methodological problems associated with the most commonly used study designs. The purpose of this licentiate thesis was to assess the strengths and limitations of the interrupted time series (ITS) design, which has gained some attention for its ability to provide valid effect estimates. Two national road safety interventions involving VRUs were selected as cases: the Swedish bicycle helmet law for children under the age 15, and the tightening of licensing rules for Class 1 mopeds. The empirical results suggest that both interventions were effective in improving the safety of VRUs. Unless other concurrent events affect the treatment population at the exact time of intervention, the effect estimates should be internally valid. One of the main limitations of the study design is the inability to identify why the interventions were successful, especially if they are complex and multifaceted. A lack of reliable exposure data can also pose a further threat to studies of interventions involving VRUs if the intervention can affect the exposure itself. It may also be difficult to generalize the exact effect estimates to other regions and populations. Future studies should consider the use of the ITS design to enhance the internal validity of before-after measurements. / Traffic-related injuries represent a global public health problem, and contribute largely to mortality and years lived with disability. Over the course of the last decades, improvements to road traffic safety and injury surveillance systems have resulted in a shift in focus from motor vehicle accidents to injury events involving vulnerable road users (VRUs), such as cyclists and moped riders. There have been calls for improvements to the evaluation of safety interventions due to methodological problems associated with the most commonly used study designs. The purpose of this licentiate thesis was to assess the strengths and limitations of the interrupted time series (ITS) design, which has gained some attention for its ability to provide valid effect estimates while accounting for secular trends. Two national interventions involving VRUs were selected as cases: the Swedish bicycle helmet law for children under the age 15, and the tightening of licensing rules for Class 1 mopeds. The empirical results suggest that both interventions were effective. These results are discussed in the light of some methodological considerations regarding internal and external validity, data quality and the ability to fully understand key causal mechanisms behind complex interventions.