Initial placement methods for Haitian adult ESOL students : the NYS place test plus profile data compared to subjective assessment

Few valid and reliable placement procedures are available to assess the English language proficiency of adults who enroll in English for Speakers of Other Languages (ESOL) programs. Whereas placement material exists for children and university ESOL students, the needs of students in adult community education programs have not been adequately addressed. Furthermore, the research suggests that a number of variables, such as, native language, age, prior schooling, length of residence, and employment are related to second language acquisition. Numerous studies contribute to our understanding of the relationship of these factors to second language acquisition of Spanish-speaking students. Again, there is a void in the research investigating the factors affecting second language acquisition and consequently, appropriate placement of Haitian Creole-speaking students. This study compared a standardized instrument, the NYS Place Test, used alone and in combination with a writing sample in English, to subjective judgement of a department coordinator for initial placement of Haitian adult ESOL students in a community education program. The study also investigated whether or not consideration of student profile data improved the accuracy of the test. Finally, the study sought to determine if a relationship existed between student profile data and those who withdrew from the program or did not enter a class after registering. Analysis of the data by crosstabulation and chi-square revealed that the standardized NYS Place Test was at least as accurate as subjective department coordinator placement and that one procedure could be substituted for li other. Although the writing sample in English improved accuracy of placement by the NYS test, the results were not significant. Of the profile variables, only length of residence was found to be significantly related to accuracy of placement using the NYS Place Test. The number of incorrect placements was higher for those students who lived in the host country from twenty-five to one hundred ten months. A post hoc analysis of NYS test scores according to level showed that those learners who placed in level three also had a significantly higher incidence of incorrect placements. No significant relationship was observed between the profile variables and those who withdrew from the program or registered but did not enter a class.

Análise de conteúdo e validação clínica do diagnóstico de enfermagem autocontrole ineficaz da saúde

The study aims to analyze the content and measures of accuracy of the nursing diagnosis Ineffective Self Health in patients undergoing hemodialysis. Study of nursing diagnosis validation carried out in two stages, namely: content analysis by judges and accuracy of clinical indicators. In the first stage, 22 judges evaluated the setting and location of the diagnosis, clinical indicators and etiological factors and their conceptual and empirical definitions. We used the binomial test to determine the proportion of the judges of the relevance of the components of the nursing diagnosis. In the second stage, we used the Latent Class Analysis for the diagnostic accuracy by evaluating 200 patients in a hemodialysis clinic in northeastern Brazil. Research approved by the Ethics Committee, under the Opinion No 387 837 and CAAE 18486413.0.0000.5537. The results show that the judges evaluated as pertinent clinical indicators 12 and 22 etiological factors. Proposed amendment of the nomenclature of five indicators and six factors and the implementation of a clinical indicator for etiology and three etiological factors for clinical indicators. In conceptual and empirical definitions, judges judged as not relevant the conceptual and empirical definitions of a clinical indicator, the conceptual definitions of two etiological factors and empirical definitions four etiological factors. Still, changes were suggested in the conceptual and empirical definitions of two clinical indicators, the conceptual definitions of 12 etiological factors and empirical definitions of 11 etiological factors. Clinical indicators analyzed in the first stage were validated clinically in patients undergoing hemodialysis. The most frequent clinical indicators were Changes in laboratory tests (100%) and daily life choices ineffective to achieve health goals (81%); and three etiological factors had a higher frequency, they are: unfavorable demographic factors (94.5%), beliefs (79%) and comorbidities (77.5%). From Latent class analysis, diagnosis prevalence was estimated at 66.28%. Clinical indicators that showed the best sensitivity measures for the nursing diagnosis Ineffective Self Health were: daily life choices ineffective to achieve health goals and Expression of difficulty with prescribed regimens. In turn, the clinical indicators of inappropriate medication use, no expression of desire to control the disease, irregular attendance to the dialysis sessions and infection were more specific as to that diagnosis. Non-adherence to treatment was the only indicator that showed confidence intervals with values for sensitivity and specificity, statistically above 0.5, being the one who has better diagnostic accuracy as the inference of the nursing diagnosis Ineffective Self Health in hemodialysis clientele. Thus, it is believed that the improvement of the components of diagnosis in question will contribute to the development of more reliable nursing interventions to the health status of the individual in hemodialysis, providing a more scientifically qualified care.

Análise de conteúdo e validação clínica do diagnóstico de enfermagem autocontrole ineficaz da saúde

The study aims to analyze the content and measures of accuracy of the nursing diagnosis Ineffective Self Health in patients undergoing hemodialysis. Study of nursing diagnosis validation carried out in two stages, namely: content analysis by judges and accuracy of clinical indicators. In the first stage, 22 judges evaluated the setting and location of the diagnosis, clinical indicators and etiological factors and their conceptual and empirical definitions. We used the binomial test to determine the proportion of the judges of the relevance of the components of the nursing diagnosis. In the second stage, we used the Latent Class Analysis for the diagnostic accuracy by evaluating 200 patients in a hemodialysis clinic in northeastern Brazil. Research approved by the Ethics Committee, under the Opinion No 387 837 and CAAE 18486413.0.0000.5537. The results show that the judges evaluated as pertinent clinical indicators 12 and 22 etiological factors. Proposed amendment of the nomenclature of five indicators and six factors and the implementation of a clinical indicator for etiology and three etiological factors for clinical indicators. In conceptual and empirical definitions, judges judged as not relevant the conceptual and empirical definitions of a clinical indicator, the conceptual definitions of two etiological factors and empirical definitions four etiological factors. Still, changes were suggested in the conceptual and empirical definitions of two clinical indicators, the conceptual definitions of 12 etiological factors and empirical definitions of 11 etiological factors. Clinical indicators analyzed in the first stage were validated clinically in patients undergoing hemodialysis. The most frequent clinical indicators were Changes in laboratory tests (100%) and daily life choices ineffective to achieve health goals (81%); and three etiological factors had a higher frequency, they are: unfavorable demographic factors (94.5%), beliefs (79%) and comorbidities (77.5%). From Latent class analysis, diagnosis prevalence was estimated at 66.28%. Clinical indicators that showed the best sensitivity measures for the nursing diagnosis Ineffective Self Health were: daily life choices ineffective to achieve health goals and Expression of difficulty with prescribed regimens. In turn, the clinical indicators of inappropriate medication use, no expression of desire to control the disease, irregular attendance to the dialysis sessions and infection were more specific as to that diagnosis. Non-adherence to treatment was the only indicator that showed confidence intervals with values for sensitivity and specificity, statistically above 0.5, being the one who has better diagnostic accuracy as the inference of the nursing diagnosis Ineffective Self Health in hemodialysis clientele. Thus, it is believed that the improvement of the components of diagnosis in question will contribute to the development of more reliable nursing interventions to the health status of the individual in hemodialysis, providing a more scientifically qualified care.

Acurácia dos indicadores clínicos do diagnóstico de enfermagem falta de adesão em pessoas vivendo com AIDS

In the early 1990s, a major milestone in the treatment of Acquired Immune Deficiency Syndrome was the development of highly active combination antiretroviral therapy. The great benefit generated by the use of this therapy was prolonging the survival of the people who got this disease, since it is no longer considered fatal, becoming a chronic condition. Despite improvements generated by this therapy, there are still many difficulties to be overcome. One is the patient adherence to their treatment, bringing challenges to services and health professionals. Hence the need for early identification of nursing diagnosis Lack of Accession so that solutions are sought by the nurse with the patient and his family. With this problem, adds to the difficulty of hospital nurses in inferring that diagnosis, especially in identifying their defining characteristics. In this context, the objective was to evaluate the accuracy of clinical indicators of nursing diagnosis Lack of Adherence to antiretroviral treatment for people living with the Acquired Immunodeficiency Syndrome. The research took place in two stages. The first consists of the evaluation of the diagnostic indicators in the study; and second, the diagnostic inference performed by specialist nurses. The first step took place in a referral hospital in the treatment of infectious diseases in the Northeast of Brazil, and data were collected through an instrument for carrying out history and physical examination and analyzed for the presence or absence of the diagnostic indicators. In the second stage, the data were sent to experts, who judged the presence or absence of the diagnosis in the studied clientele. The project was submitted to the Ethics Committee of the Federal University of Rio Grande do Norte, obtaining approval with the General Certificate for Ethics Assessment (CAAE) No 46206215.3.0000.5537. Data were analyzed using descriptive and inferential statistics. Test were used Fisher's exact, chi-square test of Pearson and logistic regression. Since the accuracy of clinical indicators was measured by sensitivity, specificity, predictive values, likelihood ratios. As a result, we identified the presence of diagnosis Lack of Accession on 69% (n = 78) of the study patients. The defining characteristics that showed statistically significant association with the diagnosis studied were: lack of adherence behavior, complications related to development, missing scheduled appointments, failure to achieve results, and exacerbation of symptoms. The characteristic with greater sensitivity was missing scheduled appointments and the highest specificity behavior of noncompliance. The logistic regression showed as predictors for the diagnosis Lack of Accession: lack of adherence behavior, missing scheduled appointments, failure to achieve results, and exacerbation of symptoms. It was concluded that the identification of clinical indicators accurately enabled a good prediction of the nursing diagnosis Lack of Accession on people living with the Acquired Immune Deficiency Syndrome, helping nurses develop early on strategies for promoting adherence to the use of antiretrovirals.

Acurácia dos indicadores clínicos do diagnóstico de enfermagem falta de adesão em pessoas vivendo com AIDS

In the early 1990s, a major milestone in the treatment of Acquired Immune Deficiency Syndrome was the development of highly active combination antiretroviral therapy. The great benefit generated by the use of this therapy was prolonging the survival of the people who got this disease, since it is no longer considered fatal, becoming a chronic condition. Despite improvements generated by this therapy, there are still many difficulties to be overcome. One is the patient adherence to their treatment, bringing challenges to services and health professionals. Hence the need for early identification of nursing diagnosis Lack of Accession so that solutions are sought by the nurse with the patient and his family. With this problem, adds to the difficulty of hospital nurses in inferring that diagnosis, especially in identifying their defining characteristics. In this context, the objective was to evaluate the accuracy of clinical indicators of nursing diagnosis Lack of Adherence to antiretroviral treatment for people living with the Acquired Immunodeficiency Syndrome. The research took place in two stages. The first consists of the evaluation of the diagnostic indicators in the study; and second, the diagnostic inference performed by specialist nurses. The first step took place in a referral hospital in the treatment of infectious diseases in the Northeast of Brazil, and data were collected through an instrument for carrying out history and physical examination and analyzed for the presence or absence of the diagnostic indicators. In the second stage, the data were sent to experts, who judged the presence or absence of the diagnosis in the studied clientele. The project was submitted to the Ethics Committee of the Federal University of Rio Grande do Norte, obtaining approval with the General Certificate for Ethics Assessment (CAAE) No 46206215.3.0000.5537. Data were analyzed using descriptive and inferential statistics. Test were used Fisher's exact, chi-square test of Pearson and logistic regression. Since the accuracy of clinical indicators was measured by sensitivity, specificity, predictive values, likelihood ratios. As a result, we identified the presence of diagnosis Lack of Accession on 69% (n = 78) of the study patients. The defining characteristics that showed statistically significant association with the diagnosis studied were: lack of adherence behavior, complications related to development, missing scheduled appointments, failure to achieve results, and exacerbation of symptoms. The characteristic with greater sensitivity was missing scheduled appointments and the highest specificity behavior of noncompliance. The logistic regression showed as predictors for the diagnosis Lack of Accession: lack of adherence behavior, missing scheduled appointments, failure to achieve results, and exacerbation of symptoms. It was concluded that the identification of clinical indicators accurately enabled a good prediction of the nursing diagnosis Lack of Accession on people living with the Acquired Immune Deficiency Syndrome, helping nurses develop early on strategies for promoting adherence to the use of antiretrovirals.

Détection du virus de l'anémie aviaire par réaction de polymérisation en chaîne (pcr) couplée à un test Elisa

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Diagnostic des systèmes temps réel modélisés par des automates à entrées sorties temporisées

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Advanced Techniques for Image Quality Assessment of Modern X-ray Computed Tomography Systems

X-ray computed tomography (CT) imaging constitutes one of the most widely used diagnostic tools in radiology today with nearly 85 million CT examinations performed in the U.S in 2011. CT imparts a relatively high amount of radiation dose to the patient compared to other x-ray imaging modalities and as a result of this fact, coupled with its popularity, CT is currently the single largest source of medical radiation exposure to the U.S. population. For this reason, there is a critical need to optimize CT examinations such that the dose is minimized while the quality of the CT images is not degraded. This optimization can be difficult to achieve due to the relationship between dose and image quality. All things being held equal, reducing the dose degrades image quality and can impact the diagnostic value of the CT examination.

A recent push from the medical and scientific community towards using lower doses has spawned new dose reduction technologies such as automatic exposure control (i.e., tube current modulation) and iterative reconstruction algorithms. In theory, these technologies could allow for scanning at reduced doses while maintaining the image quality of the exam at an acceptable level. Therefore, there is a scientific need to establish the dose reduction potential of these new technologies in an objective and rigorous manner. Establishing these dose reduction potentials requires precise and clinically relevant metrics of CT image quality, as well as practical and efficient methodologies to measure such metrics on real CT systems. The currently established methodologies for assessing CT image quality are not appropriate to assess modern CT scanners that have implemented those aforementioned dose reduction technologies.

Thus the purpose of this doctoral project was to develop, assess, and implement new phantoms, image quality metrics, analysis techniques, and modeling tools that are appropriate for image quality assessment of modern clinical CT systems. The project developed image quality assessment methods in the context of three distinct paradigms, (a) uniform phantoms, (b) textured phantoms, and (c) clinical images.

The work in this dissertation used the “task-based” definition of image quality. That is, image quality was broadly defined as the effectiveness by which an image can be used for its intended task. Under this definition, any assessment of image quality requires three components: (1) A well defined imaging task (e.g., detection of subtle lesions), (2) an “observer” to perform the task (e.g., a radiologists or a detection algorithm), and (3) a way to measure the observer’s performance in completing the task at hand (e.g., detection sensitivity/specificity).

First, this task-based image quality paradigm was implemented using a novel multi-sized phantom platform (with uniform background) developed specifically to assess modern CT systems (Mercury Phantom, v3.0, Duke University). A comprehensive evaluation was performed on a state-of-the-art CT system (SOMATOM Definition Force, Siemens Healthcare) in terms of noise, resolution, and detectability as a function of patient size, dose, tube energy (i.e., kVp), automatic exposure control, and reconstruction algorithm (i.e., Filtered Back-Projection– FPB vs Advanced Modeled Iterative Reconstruction– ADMIRE). A mathematical observer model (i.e., computer detection algorithm) was implemented and used as the basis of image quality comparisons. It was found that image quality increased with increasing dose and decreasing phantom size. The CT system exhibited nonlinear noise and resolution properties, especially at very low-doses, large phantom sizes, and for low-contrast objects. Objective image quality metrics generally increased with increasing dose and ADMIRE strength, and with decreasing phantom size. The ADMIRE algorithm could offer comparable image quality at reduced doses or improved image quality at the same dose (increase in detectability index by up to 163% depending on iterative strength). The use of automatic exposure control resulted in more consistent image quality with changing phantom size.

Based on those results, the dose reduction potential of ADMIRE was further assessed specifically for the task of detecting small (<=6 mm) low-contrast (<=20 HU) lesions. A new low-contrast detectability phantom (with uniform background) was designed and fabricated using a multi-material 3D printer. The phantom was imaged at multiple dose levels and images were reconstructed with FBP and ADMIRE. Human perception experiments were performed to measure the detection accuracy from FBP and ADMIRE images. It was found that ADMIRE had equivalent performance to FBP at 56% less dose.

Using the same image data as the previous study, a number of different mathematical observer models were implemented to assess which models would result in image quality metrics that best correlated with human detection performance. The models included naïve simple metrics of image quality such as contrast-to-noise ratio (CNR) and more sophisticated observer models such as the non-prewhitening matched filter observer model family and the channelized Hotelling observer model family. It was found that non-prewhitening matched filter observers and the channelized Hotelling observers both correlated strongly with human performance. Conversely, CNR was found to not correlate strongly with human performance, especially when comparing different reconstruction algorithms.

The uniform background phantoms used in the previous studies provided a good first-order approximation of image quality. However, due to their simplicity and due to the complexity of iterative reconstruction algorithms, it is possible that such phantoms are not fully adequate to assess the clinical impact of iterative algorithms because patient images obviously do not have smooth uniform backgrounds. To test this hypothesis, two textured phantoms (classified as gross texture and fine texture) and a uniform phantom of similar size were built and imaged on a SOMATOM Flash scanner (Siemens Healthcare). Images were reconstructed using FBP and a Sinogram Affirmed Iterative Reconstruction (SAFIRE). Using an image subtraction technique, quantum noise was measured in all images of each phantom. It was found that in FBP, the noise was independent of the background (textured vs uniform). However, for SAFIRE, noise increased by up to 44% in the textured phantoms compared to the uniform phantom. As a result, the noise reduction from SAFIRE was found to be up to 66% in the uniform phantom but as low as 29% in the textured phantoms. Based on this result, it clear that further investigation was needed into to understand the impact that background texture has on image quality when iterative reconstruction algorithms are used.

To further investigate this phenomenon with more realistic textures, two anthropomorphic textured phantoms were designed to mimic lung vasculature and fatty soft tissue texture. The phantoms (along with a corresponding uniform phantom) were fabricated with a multi-material 3D printer and imaged on the SOMATOM Flash scanner. Scans were repeated a total of 50 times in order to get ensemble statistics of the noise. A novel method of estimating the noise power spectrum (NPS) from irregularly shaped ROIs was developed. It was found that SAFIRE images had highly locally non-stationary noise patterns with pixels near edges having higher noise than pixels in more uniform regions. Compared to FBP, SAFIRE images had 60% less noise on average in uniform regions for edge pixels, noise was between 20% higher and 40% lower. The noise texture (i.e., NPS) was also highly dependent on the background texture for SAFIRE. Therefore, it was concluded that quantum noise properties in the uniform phantoms are not representative of those in patients for iterative reconstruction algorithms and texture should be considered when assessing image quality of iterative algorithms.

The move beyond just assessing noise properties in textured phantoms towards assessing detectability, a series of new phantoms were designed specifically to measure low-contrast detectability in the presence of background texture. The textures used were optimized to match the texture in the liver regions actual patient CT images using a genetic algorithm. The so called “Clustured Lumpy Background” texture synthesis framework was used to generate the modeled texture. Three textured phantoms and a corresponding uniform phantom were fabricated with a multi-material 3D printer and imaged on the SOMATOM Flash scanner. Images were reconstructed with FBP and SAFIRE and analyzed using a multi-slice channelized Hotelling observer to measure detectability and the dose reduction potential of SAFIRE based on the uniform and textured phantoms. It was found that at the same dose, the improvement in detectability from SAFIRE (compared to FBP) was higher when measured in a uniform phantom compared to textured phantoms.

The final trajectory of this project aimed at developing methods to mathematically model lesions, as a means to help assess image quality directly from patient images. The mathematical modeling framework is first presented. The models describe a lesion’s morphology in terms of size, shape, contrast, and edge profile as an analytical equation. The models can be voxelized and inserted into patient images to create so-called “hybrid” images. These hybrid images can then be used to assess detectability or estimability with the advantage that the ground truth of the lesion morphology and location is known exactly. Based on this framework, a series of liver lesions, lung nodules, and kidney stones were modeled based on images of real lesions. The lesion models were virtually inserted into patient images to create a database of hybrid images to go along with the original database of real lesion images. ROI images from each database were assessed by radiologists in a blinded fashion to determine the realism of the hybrid images. It was found that the radiologists could not readily distinguish between real and virtual lesion images (area under the ROC curve was 0.55). This study provided evidence that the proposed mathematical lesion modeling framework could produce reasonably realistic lesion images.

Based on that result, two studies were conducted which demonstrated the utility of the lesion models. The first study used the modeling framework as a measurement tool to determine how dose and reconstruction algorithm affected the quantitative analysis of liver lesions, lung nodules, and renal stones in terms of their size, shape, attenuation, edge profile, and texture features. The same database of real lesion images used in the previous study was used for this study. That database contained images of the same patient at 2 dose levels (50% and 100%) along with 3 reconstruction algorithms from a GE 750HD CT system (GE Healthcare). The algorithms in question were FBP, Adaptive Statistical Iterative Reconstruction (ASiR), and Model-Based Iterative Reconstruction (MBIR). A total of 23 quantitative features were extracted from the lesions under each condition. It was found that both dose and reconstruction algorithm had a statistically significant effect on the feature measurements. In particular, radiation dose affected five, three, and four of the 23 features (related to lesion size, conspicuity, and pixel-value distribution) for liver lesions, lung nodules, and renal stones, respectively. MBIR significantly affected 9, 11, and 15 of the 23 features (including size, attenuation, and texture features) for liver lesions, lung nodules, and renal stones, respectively. Lesion texture was not significantly affected by radiation dose.

The second study demonstrating the utility of the lesion modeling framework focused on assessing detectability of very low-contrast liver lesions in abdominal imaging. Specifically, detectability was assessed as a function of dose and reconstruction algorithm. As part of a parallel clinical trial, images from 21 patients were collected at 6 dose levels per patient on a SOMATOM Flash scanner. Subtle liver lesion models (contrast = -15 HU) were inserted into the raw projection data from the patient scans. The projections were then reconstructed with FBP and SAFIRE (strength 5). Also, lesion-less images were reconstructed. Noise, contrast, CNR, and detectability index of an observer model (non-prewhitening matched filter) were assessed. It was found that SAFIRE reduced noise by 52%, reduced contrast by 12%, increased CNR by 87%. and increased detectability index by 65% compared to FBP. Further, a 2AFC human perception experiment was performed to assess the dose reduction potential of SAFIRE, which was found to be 22% compared to the standard of care dose.

In conclusion, this dissertation provides to the scientific community a series of new methodologies, phantoms, analysis techniques, and modeling tools that can be used to rigorously assess image quality from modern CT systems. Specifically, methods to properly evaluate iterative reconstruction have been developed and are expected to aid in the safe clinical implementation of dose reduction technologies.

Understanding Antenatal Genetics Services in Sri Lanka: Current Landscape of Screening and Diagnostic Services and Contextual Factors Influencing Their Availability and Uptake

Background: Too little information is available on Sri Lanka’s current capacity to provide community genetic services—antenatal genetic services in particular—to understand whether building that capacity could further improve and reduce disparity in maternal and child health. This qualitative research project seeks to gather information on congenital disorders, routine antenatal care, and the current state of antenatal screening testing services within that routine antenatal to assess the feasibility of and the need for scaling up antenatal genetics services in Sri Lanka. Methods: Nineteen key informant (KI) interviews were conducted with stakeholders in antenatal care and genetic services. Seven focus group discussions were held with a total of 56 Public Health Midwives (PHMs), the health workers responsible for antenatal care at the field level. Transcripts for all interviews and FGDs were analyzed for key themes, and themes were categorized to address the specific aims of the project. Results: Antenatal genetic services play a minor role in antenatal care, with screening and diagnostic procedures available in the private sector and paid for out-of-pocket. KIs and PHMs expect that demand for antenatal genetic services will increase as patients’ purchasing power and knowledge grow but note that prohibitive abortion laws limit the ability of patients to act on test results. Genetic services compete for limited financial and human resources in the free public health system, and inadequate information on the prevalence of congenital disorders limits the ability to understand whether funding for services related to those disorders should be increased. A number of alternatives to scaling up antenatal genetic services within the free health system might be better suited to the Sri Lankan structural and social context. Conclusions: Scaling up antenatal genetic services within the public health system is not feasible in the current financial, legal, and human resource context. Yet current availability and utilization patterns contribute to regional and economic disparities, suggesting that stasis will not bring continued improvements in maternal and child health. More information on the burden of congenital disorders is necessary to fully understand if and how antenatal genetic service availability should be increased in Sri Lanka, but even before that information is gathered, examination of policies for patient referral, termination of pregnancy, and government support for individuals with genetic disease are steps that might bring extend improvements and reduce disparity in maternal and child health.

Détection du virus de l'anémie aviaire par réaction de polymérisation en chaîne (pcr) couplée à un test Elisa

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Diagnostic des systèmes temps réel modélisés par des automates à entrées sorties temporisées

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Constructing the Vulvar Pain Assessment Questionnaire Inventory

The goals of this program of research were to examine the link between self-reported vulvar pain and clinical diagnoses, and to create a user-friendly assessment tool to aid in that process. These goals were undertaken through a series of four empirical studies (Chapters 2-6): one archival study, two online studies, and one study conducted in a Women’s Health clinic. In Chapter 2, the link between self-report and clinical diagnosis was confirmed by extracting data from multiple studies conducted in the Sexual Health Research Laboratory over the course of several years. We demonstrated the accuracy of diagnosis based on multiple factors, and explored the varied gynecological presentation of different diagnostic groups. Chapter 3 was based on an online study designed to create the Vulvar Pain Assessment Questionnaire (VPAQ) inventory. Following the construct validation approach, a large pool of potential items was created to capture a broad selection of vulvar pain symptoms. Nearly 300 participants completed the entire item pool, and a series of factor analyses were utilized to narrow down the items and create scales/subscales. Relationships were computed among subscales and validated scales to establish convergent and discriminant validity. Chapters 4 and 5 were conducted in the Department of Obstetrics & Gynecology at Oregon Health & Science University. The brief screening version of the VPAQ was employed with patients of the Program in Vulvar Health at the Center for Women’s Health. The accuracy and usefulness of the VPAQscreen was determined from the perspective of patients as well as their health care providers, and the treatment-seeking experiences of patients was explored. Finally, a second online study was conducted to confirm the factor structure, internal consistency, and test-retest reliability of the VPAQ inventory. The results presented in these chapters confirm the link between targeted questions and accurate diagnoses, and provide a guideline that is useful and accessible for providers and patients.

Improved Accuracy in Optical Motion Capture Measurements Leads to Increased Sensitivity to Kinematic Changes

Clinical optical motion capture allows us to obtain kinematic and kinetic outcome measures that aid clinicians in diagnosing and treating different pathologies affecting healthy gait. The long term aim for gait centres is for subject-specific analyses that can predict, prevent, or reverse the effects of pathologies through gait retraining. To track the body, anatomical segment coordinate systems are commonly created by applying markers to the surface of the skin over specific, bony anatomy that is manually palpated. The location and placement of these markers is subjective and precision errors of up to 25mm have been reported [1]. Additionally, the selection of which anatomical landmarks to use in segment models can result in large angular differences; for example angular differences in the trunk can range up to 53o for the same motion depending on marker placement [2]. These errors can result in erroneous kinematic outcomes that either diminish or increase the apparent effects of a treatment or pathology compared to healthy data. Our goal was to improve the accuracy and precision of optical motion capture outcome measures. This thesis describes two separate studies. In the first study we aimed to establish an approach that would allow us to independently quantify the error among trunk models. Using this approach we determined if there was a best model to accurately track trunk motion. In the second study we designed a device to improve precision for test, re-test protocols that would also reduce the set-up time for motion capture experiments. Our method to compare a kinematically derived centre of mass velocity to one that was derived kinetically was successful in quantifying error among trunk models. Our findings indicate that models that use lateral shoulder markers as well as limit the translational degrees of freedom of the trunk through shared pelvic markers result in the least amount of error for the tasks we studied. We also successfully reduced intra- and inter-operator anatomical marker placement errors using a marker alignment device. The improved accuracy and precision resulting from the methods established in this thesis may lead to increased sensitivity to changes in kinematics, and ultimately result in more consistent treatment outcomes.

Item and task difficulty in a B2 reading examination: perceptions of test-takers and CEFR alignment experts compared with psychometric measurements

The article presents a study of a CEFR B2-level reading subtest that is part of the Slovenian national secondary school leaving examination in English as a foreign language, and compares the test-taker actual performance (objective difficulty) with the test-taker and expert perceptions of item difficulty (subjective difficulty). The study also analyses the test-takers’ comments on item difficulty obtained from a while-reading questionnaire. The results are discussed in the framework of the existing research in the fields of (the assessment of) reading comprehension, and are addressed with regard to their implications for item-writing, FL teaching and curriculum development.

Variation in pre-PCR processing of FFPE samples leads to discrepancies in BRAF and EGFR mutation detection: a diagnostic RING trial.

AIMS: Mutation detection accuracy has been described extensively; however, it is surprising that pre-PCR processing of formalin-fixed paraffin-embedded (FFPE) samples has not been systematically assessed in clinical context. We designed a RING trial to (i) investigate pre-PCR variability, (ii) correlate pre-PCR variation with EGFR/BRAF mutation testing accuracy and (iii) investigate causes for observed variation. METHODS: 13 molecular pathology laboratories were recruited. 104 blinded FFPE curls including engineered FFPE curls, cell-negative FFPE curls and control FFPE tissue samples were distributed to participants for pre-PCR processing and mutation detection. Follow-up analysis was performed to assess sample purity, DNA integrity and DNA quantitation. RESULTS: Rate of mutation detection failure was 11.9%. Of these failures, 80% were attributed to pre-PCR error. Significant differences in DNA yields across all samples were seen using analysis of variance (p