Ultrahigh-dimensional variable selection is of great importance in the statistical research. And independence screening is a powerful tool to select important variable when there are massive variables. Some commonly used independence screening procedures are based on single replicate data and are not applicable to longitudinal data. This motivates us to propose a new Sure Independence Screening (SIS) procedure to bring the dimension from ultra-high down to a relatively large scale which is similar to or smaller than the sample size. In chapter 2, we provide two types of SIS, and their iterative extensions (iterative SIS) to enhance the finite sample performance. An upper bound on the number of variables to be included is derived and assumptions are given under which sure screening is applicable. The proposed procedures are assessed by simulations and an application of them to a study on systemic lupus erythematosus illustrates the practical use of these procedures. After the variables screening process, we then explore the relationship among the variables. Graphical models are commonly used to explore the association network for a set of variables, which could be genes or other objects under study. However, graphical modes currently used are only designed for single replicate data, rather than longitudinal data. In chapter 3, we propose a penalized likelihood approach to identify the edges in a conditional independence graph for longitudinal data. We used pairwise coordinate descent combined with second order cone programming to optimize the penalized likelihood and estimate the parameters. Furthermore, we extended the nodewise regression method the for longitudinal data case. Simulation and real data analysis exhibit the competitive performance of the penalized likelihood method. / Doctor of Philosophy / Longitudinal data have received a considerable amount of attention in the fields of health science studies. The information from this type of data could be helpful with disease detection and control. Besides, a graph of factors related to the disease can also be built up to represent their relationships between each other. In this dissertation, we develop a framework to find out important factor(s) from thousands of factors in longitudinal data that is/are related to the disease. In addition, we develop a graphical method that can show the relationship among the important factors identified from the previous screening. In practice, combining these two methods together can identify important factors for a disease as well as the relationship among the factors, and thus provide us a deeper understanding about the disease.

Purpose: Given that CRC Screening disparities in people experiencing homelessness has been heavily understudied, the purpose of this study is to assess how existing knowledge and access to resources about CRC screenings affect the ability to obtain CRC screenings in people experiencing homelessness in Central Florida. Methods: In March 2023, a team of researchers surveyed subjects who do not have stable housing in two Central Florida locations: a local shelter and a resource center serving the predominantly unsheltered. The survey assessed current understanding of CRC screenings and available/lacking resources necessary for completing CRC screening in this population. There was a total sample size of 75 participants, with 36 participants from the shelter and 39 from the service center location. Our inclusion criteria included those who are undomiciled, age 45 and over who speak Spanish or English. Results: The results indicate that there is a statistical difference between those who are screened and not screened when assessing provider counseling (p<0.001), awareness of how to get screened (p<0.001) and access to the same medical provider every visit (p=0.0389). In regard to receipt of CRC screening, there were no statistically significant results when assessing demographics and other resource-related factors. Conclusion: Because data was collected in locations that provided resources, this study may not be representative of all undomiciled individuals in Florida, especially in rural areas. Our results imply a need for provider counseling, patient education and access to a primary care provider. More research needs to be conducted from the physician perspective to understand the context of existing barriers to CRC screening.

Efficient passenger flow is a crucial objective at both small and larger airports. One central part of this is the handling of checked luggage which is influenced by necessary security screening. Within this thesis, these processes are studied at San Luis Obispo County Regional Airport. The underlying problem of the airport is its outbound luggage system which was already suffering from delays prior to Covid-19. Delays were never measured and the bottleneck responsible for them was never identified. However, expected growth in passenger and flight volume necessitates to predict when customer dissatisfaction and extensive luggage delays are inevitable, given that the airport does not plan to change the baggage screening system in the near future. In order to understand the dependencies within said system, process flowcharts for baggage-related activities are defined and translated into a simulation model. After model verification and validation, scenarios of expanding the flight schedule during different times of the day are tested while monitoring the number of bags failing to be loaded into the respective aircraft in time. Further scenarios of model adjustments are used to monitor how the number of missed bags changes while maintaining an expanded flight schedule. Model adjustments were made by changing single parameters such as the scan time or single resources each. Simulation experiments have shown that the number of additional flights that can be added to the flight schedule of February 2020 depend on the time of the day. For instance, the current outbound luggage conveyor system’s capacity is sufficient to cover 1 additional early morning flight, and up to 3 afternoon flights. Experiments with model parameter adjustments led to identifying the luggage scanner as the bottleneck of the luggage system, whereas other tested parameter adjustments showed to have minimal impact on the number of missed bags. Since the model’s flight plan can be conveniently adjusted in the connected Excel database, the model could be used as a tactical decision tool for capacity analysis.

Yes / Objectives; To evaluate radiation doses for all low-dose CT scans performed during the first year of a lung screening trial. Methods; For all lung screening scans that were performed using a CT protocol that delivered image quality meeting the RSNA QIBA criteria, , radiation dose metrics, participant height, weight, gender and age were recorded. Values of CTDIvol and DLP were evaluated as a function of weight in order to assess the performance of the scan protocol across the participant cohort. Calculated effective doses were used to establish the additional lifetime attributable cancer risks arising from trial scans. Results; Median values of CTDIvol, DLP and effective dose (IQR) from the 3521 scans were 1.1mGy (0.70), 42.4mGycm (24.9) and 1.15mSv (0.67), whilst for 60-80kg participants the values were 1.0mGy (0.30), 35.8mGycm (11.4) and 0.97mSv (0.31). A statistically significant correlation between CTDIvol and weight was identified for males (r=0.9123, p<0.001) and females (r=0.9052, p<0.001), however the effect of gender on CTDIvol was not statistically significant (p=0.2328) despite notable differences existing at the extremes of the weight range. The additional lifetime attributable cancer risks from a single scan were in the range 0.001-0.006%. Conclusions; Low radiation doses can be achieved across a typical lung screening cohort using scan protocols that have been shown to deliver high levels of image quality. The observed dose levels may be considered as typical values for lung screening scans on similar types of scanner for an equivalent participant cohort. Advances in Knowledge; Presentation of typical radiation dose levels for CT lung screening examinations in a large UK trial. Effective radiation doses can be of the order of 1mSv for standard sized participants. Lifetime attributable cancer risks resulting from a single LDCT scan did not exceed 0.006%. / The Yorkshire Lung Screening Trial is funded by Yorkshire Cancer Research (award reference L403).

Adverse Childhood Experiences (ACEs) are traumatic events that individuals experience in childhood that have been linked to problems with physical and mental health in adulthood (Felitti et al., 1998). Previous research suggests that ACEs are prevalent in almost two-thirds of youth regardless of location across the world and that when an individual experiences three or more ACEs, their quality-adjusted life expectancy is found to decrease (Carlson et al., 2019; Jia & Lubetkin, 2020). Although ACEs have been associated with negative outcomes, not all individuals who experience trauma exhibit problematic behavior and are considered to have high levels of resilience (Agaiba & Wilson, 2005; Charney, 2012). Positive Childhood Experiences (PCEs) are characterized as positive events in childhood that occur in children’s lives that serve as a buffer or prevent symptomology related to traumatic events. The purpose of this study was to examine the relationship between students’ self-reported exposure of ACEs, PCEs, and behavioral problems in the school setting. Furthermore, the study sought to investigate whether students’ positive experiences moderate the relationship between negative experiences and behavioral problems. Participants included 35 students from a middle and high school located in the Southeastern United States. Results indicated a significant positive relationship between exposure to ACEs and reported behavioral problems and suggest that ACEs positively predict students’ self-reported behavioral problems. Additionally, a significant negative relationship between PCEs and reported behavioral problems by students was found, and results suggest that PCEs negatively predict students’ behavioral problems. Results of the moderation analysis indicate that PCEs do not have a significant moderation effect between ACEs and behavioral problems. Results of the current study have implications for changing the current practices for universal screening of behavior in the school setting, particularly with the inclusion of ACEs within the screening process.

Enterokokken gehören zu den bedeutendsten nosokomialen Keimen. Die Verbreitung von Multiresistenzen bei diesen Keimen stellt das deutsche Gesundheitssystem aufgrund von wenigen verbleibenden Therapieoptionen von Infektionen vor große Probleme. Die KRINKO des Robert-Koch-Instituts empfiehlt als mögliche Präventionsmaßnahme ein regelmäßiges Screening auf Enterokokken mit Vancomycin- bzw. Linezolid-Resistenzen. Ziel dieser Arbeit war es, ein kulturelles Screeningverfahren für Linezolid-resistente Enterokokken (LRE) zu entwickeln und dieses anschließend im Routinescreening des Universitätsklinikums Würzburg zu etablieren. Es wurde ein Verfahren entwickelt, welches sich aus einem Anreicherungsschritt mit 3 mg/l Linezolid versetzter selektiver Enterococcosel-Bouillon und einer anschließenden Subkultivierung auf Linezolid-Enterococcosel-Agar mit 4 mg/l Linezolid zusammensetzt. In einer Simulation von klinischen Bedingungen zeigte sich eine gute Sensitivität und Spezifität. Das entwickelte Screeningverfahren wurde mit einem geringen Sensitivitätsverlust und ohne zusätzliche Belastung für die Patienten in das bestehende Routinescreening für Vancomycin-resistente Enterokokken des Universitätsklinikums Würzburg eingegliedert. Die nachgewiesen LRE zeigten unterschiedliche Resistenzmechanismen, wobei bei dem Großteil der Isolate Resistenzgene nachgewiesen werden konnten. Des Weiteren zeigte sich ein breit gestreuter genetischer Hintergrund. Viele der Isolate gehörten genetischen Gruppen an, welche bisher kaum in hospitalisierten Patienten nachgewiesen wurden. Durch die labortechnische Weiterentwicklung von Screeningverfahren für LRE können diese möglicherweise bald routinemäßig in vielen Kliniken etabliert werden. / Enterococci are one of the most important nosocomial pathogens. The spread of multiresistance in these pathogens poses a major problem for the German healthcare system due to the few remaining treatment options for infections. The Robert Koch Institute's KRINKO recommends regular screening for enterococci with vancomycin or linezolid resistance as a possible preventive measure. The aim of this work was to develop a cultural screening method for linezolid-resistant enterococci (LRE) and to establish it in routine screening at the University Hospital of Würzburg. A procedure was developed consisting of an enrichment step with 3 mg/l linezolid-added selective enterococcosel broth and a subsequent subcultivation on linezolid-enterococcosel agar with 4 mg/l linezolid. A simulation of clinical conditions showed good sensitivity and specificity. The developed screening method was integrated into the existing routine screening for vancomycin-resistant enterococci at the University Hospital of Würzburg with little loss of sensitivity and no additional burden for patients. The detected LRE showed different resistance mechanisms, with resistance genes being detected in the majority of isolates. In addition, a broad genetic background was found. Many of the isolates belonged to genetic groups that have rarely been detected in hospitalized patients. With further development of laboratory screening methods for LRE, it may soon be possible to establish them routinely in many hospitals.

Under år 2003-2009 utgjorde hypertensiva sjukdomar, såsom eklampsi och preeklampsi, 14,0% av värdens mödradödlighet. Preeklampsi kännetecknas vanligtvis av kliniska observationer av hypertoni och signifikant proteinuri i graviditetens andra trimester. Inom diagnostiken används en riskbedömningsprogramvara som kan beräkna vilken sannolikhetsgrad den havande kvinnan har för att utveckla preeklampsi. Förutom mätning av blodtryck och proteinuri har biomarkören placenta growth factor 1 (PlGF-1) visat ett högt prediktivt värde vid bedömningen. Studien syftade till att kartlägga och fördjupa sig i metoderna som analyserar biomarkören samt verifiera metoden för PlGF på instrumentet Brahms Kryptor compact plus. Fördjupningen baserades på granskning av vetenskapliga artiklar och resulterade i två manuella och tre automatiserade metoder. Metoden Quantikine användes i 47% av artiklarna och konstaterades som studiens golden standard. Vid jämförelse av metoderna sågs en lägre bakgrundsstörning, en högre sensitivitet samt en kortare analystid hos de automatiserade metoderna. Den laborativa verifieringen innefattade bestämning av överensstämmelse med externt laboratorium, beräkning av instrumentets provsmitta mellan höga och låga prov samt kvantifiering av inomserie- och mellanliggande precision. Verifieringen resulterade i en god överensstämmelse (r=0,953, p=0,327) med det externa laboratoriet, en konstaterad provsmitta på 0,04% samt en god precision inom leverantörens angivelser. / Between 2003-2009 hypertensive disorders as eclampsia and preeclampsia constituted 14.0% of the world’s maternal mortality. Preeclampsia characterize as clinical observations of hypertension and significant proteinuria in the second trimester of pregnancy. In diagnostics a risk assessment software is normally used to estimate the probability of developing the disorder. Besides calculating the blood pressure and proteinuria, the placenta growth factor 1 (PlGF-1) has proven to possess a high predictive value. The study’s aim was to chart the different methods used to quantify the biomarker and verify the method for PlGF on Brahms Kryptor compact plus. The recess was based on review of scientific articles and resulted in the findings of two manual and three automated methods. The method Quantikine was used in 47% of the articles and was seen as the golden standard of the study. When comparing the methods a lower signal to noise-ratio, a higher sensitivity and a shorter assay time was observed in the automated methods. The verification contained determination of compliance with an external laboratory, calculation of carry over and quantification of inter-assay and intra-assay precision. The verification resulted in a good compliance (r=0.953, p=0,327) with the external laboratory, a carry over at 0,04% and a good precision within the providers indication.

Bakgrund: Våld i nära relation är ett samhällsproblem. Genom att utföra screening kan vårdpersonalen identifiera och stödja kvinnor som utsatts för våld, vilket är viktigt för att kunna erbjuda adekvat vård och främja en god hälsa. Syfte: Syftet med litteraturöversikten är att kartlägga kvinnliga patienters upplevelser av att vårdpersonal frågar om våld i nära relation. Metod: Litteratursökning gjordes i databaserna PubMed och CINAHL. Efter kvalitetsgranskning kvarstod 15 artiklar, varav 14 med kvalitativ ansats och en med mixad metod som därefter analyserats. Resultat: Kvinnor upplevde att det var positivt att bli tillfrågade då de inte ansåg att de var kapabla till att be om hjälp. Det ansågs viktigt att vårdpersonalen hade rätt kompetens. Att vårdpersonal frågade regelbundet, på en säker plats samt erbjöd information och rådgivning var viktigt. Det var också viktigt hur vårdpersonal ställde frågan, deras beteende, samt om de verkade intresserade. Kvinnor kunde dock uppleva att bli tillfrågade upplevdes som ett hot mot deras säkerhet. Brist på information ansågs som ett hinder för att få hjälp. Slutsats: Det finns en efterfrågan hos kvinnor att vårdpersonal måste kunna tillgodose deras behov av information och ha kompetens inom ämnet, samt att kvinnorna vill uppleva att de är säkra om de berättar om våldsutsatthet. Ytterligare forskning behövs för att utreda vilka förhållanden som är optimala för att kvinnor ska vilja anförtro sig åt vårdpersonalen. / Background: Intimate partner violence is a public health problem. By performing screening, health care professionals are able to identify and support women who have been exposed to intimate partner violence. This is important in order to provide women with health care that is appropriate for their needs. Aim: The aim is to survey patient's experiences of health professionals asking about intimate partner violence. Method: Systematic searches were performed in the databases: PubMed and CINAHL. After the qualitative review, 15 articles were chosen, fourteen of which were qualitative studies and one of mixed method for analyzing. Findings: Women felt it was good to be asked about intimate partner violence as they were not able to ask for help themselves. It was considered important that the health care professionals had the knowledge and qualification to ask about it. It was also important that health care professionals asked regularly, in a safe place and offered information and advice when needed. It was also important how health professionals posed the question, and how they acted while doing it. Women, however, could experience to be asked as a threat to their safety. Lack of information was also seen as an obstacle for help. Conclusions: According to women, health care professionals must be able to meet their needs for information and have expertise in the subject. Women also want to feel safe when disclosing about intimate partner violence. Further research in the topic is encouraged. This is needed to probe favorable conditions for asking women about intimate partner violence.

Corporate Social Responsibility (CSR) har vuxit fram som resultat av en ökad medvetenhet för etik- och miljöfrågor i samhället. I takt med denna utveckling har ansvarsfulla investeringar blivit ett självklart inslag i nästan all fondförvaltning. Fondbolag bestämmer själva vilka placeringskriterier som investeringar måste uppfylla för att ingå i deras etiska och hållbara fonder. Detta skapar förvirrande förutsättningar för privatspararen som vill investera ansvarsfullt. Denna studie har utifrån en kartläggning av Premiepensionens miljö- och etikmärkta fonder studerat hur investeringsstrategier ser ut hos dessa fonder och varför, samt vilka kriterier som måste uppfyllas. Detta har kompletterats med intervjuer med representanter från fem olika institutioner som verkar på fondmarknaden. Det teoretiska ramverket för denna studie utgörs av en analysmodell av tre olika investeringsstrategier; negativ screening, positiv screening samt aktiv påverkan. Utöver detta används även legitimitetsteorin; teorin om att företag agerar för att erhålla ett slags erkännande från sina intressenter. Resultatet visar att negativ screening förekommer i störst utsträckning, följt av aktiv påverkan och sist positiv screening. Trots att negativ screening kritiseras av de som är väl insatta i branschen för att vara kontraproduktiv är den ändå mest populär. Avgörande kriterier varierar mellan strategier, men miljö- och socialt ansvar utmärker sig som viktiga bedömningsgrunder. Detta antas vara ett resultat av de ökade kraven som ställs från omvärlden. Resultatet visar att fondbolag är benägna att välja den strategi som utlovar mest legitimitet samt är mest kostnadseffektiv.

Bakgrund: Postoperativ förvirring är en vanligt förekommande komplikation på postoperativa vårdavdelningar. Ökad kunskap om postoperativ förvirring och hur tillståndet kan förebyggas, upptäckas och behandlas kan förkorta vårdtider, minska andra allvarliga postoperativa komplikationer samt minska kostnaderna för sjukvården. Syfte: Syftet var att undersöka vilka omvårdnadsstrategier och omvårdnadsåtgärder sjuksköterskor använder för att förebygga, upptäcka och behandla postoperativ förvirring och därmed minska onödigt lidande för patienterna på postoperativa avdelningar. Metod: Metoden var en kvalitativ intervjustudie med åtta sjuksköterskor på två postoperativa avdelningar på ett sjukhus i Mellansverige. En kvalitativ innehållsanalys användes för analysering av insamlade data. Resultat: Resultatet visade att sjuksköterskor hade olika omvårdnadsstrategier för omhändertagandet av patienter med risk för postoperativ förvirring samt med förvirrade patienter. Innehållsanalysen resulterade i sex kategorier; 1. Att se patienten, 2. Att förebygga, 3. Att upptäcka, 4. Att behandla, 5. Hinder för omvårdnad samt 6. Sjuksköterskans behov för att kunna ge omvårdnad. Slutsats: Resultatet visade att sjuksköterskor ansåg att tidigt upptäckt av postoperativ förvirring är viktigt eftersom förvirringen kan leda till vårdskador och andra komplikationer. En tydlig strategi för att screena riskpatienter och för att upptäcka och behandla förvirring saknades och inget bedömningsinstrument för att mäta graden av förvirring användes. Sjuksköterskor önskade mer resurser för att kunna upptäcka och behandla postoperativ förvirring samt att postoperativ förvirring fick större fokus på avdelningen. / Background: Postoperative confusion is a common complication in postoperative care units. Increased knowledge of prevention, detection and treatment of postoperative can shorten hospitalization for these patients and reduce other serious postoperative complications and costs to healthcare. Purpose: The aim of this study was to investigate which nursing strategies and nursing measures nurses use to prevent, detect and treat postoperative confusion, and thereby reduce unnecessary suffering for patients in postoperative care unit. Method: The method used was a qualitative interview study including eight nurses at two postoperative care units at a hospital central Sweden. A qualitative content analysis was used for analysis of the collected data. Results: The results showed that nurses had different nursing strategies for the treatment of patients at risk for postoperative confusion and for confused patients. The content analysis resulted in six categories; 1. To see the patient , 2. To prevent, 3. To detect, 4. To treat, 5. Complications to nursing, and 6. Nurse’s needs to provide nursing. Conclusion: Nurses considered that early detection of postoperative confusion is important because confusion can lead to care injuries and other complications. A clear strategy for screening risk patients, detecting and treating of confusion was missing. No assessment tool was used för measuring the grade of confusion. Nurses wanted more resources to detect and treat postoperative confusion and more focus on postoperative confusion on care units.