1,720,974 research outputs found
The Role of Comorbidities on Outcomes After Traumatic Brain Injury
No full textTraumatic brain injury (TBI) is a leading cause of disability and mortality worldwide resulting in a myriad of difficulties including cognitive impairment, functional disability, postconcussion syndrome (PCS) symptoms and diminished quality of life, that have been known to last many years. The epidemiological transition coinciding with rising trends in both TBIs and chronic health conditions, requires greater attention to be placed on understanding the outcomes of those with TBI who are increasingly also likely to have a health condition or comorbidity. In doing so, it furthers our current limited understanding about the additional mediating and/or moderating role that comorbidities are likely to play on delayed recovery and difficulties experienced after TBI. In the measurement of such outcomes, detailed examination of the psychometric properties of scales using modern methods such as Rasch analysis plays a central role. Psychometric analysis not only ensures that outcome measures uphold validity and reliability for use in the intended populations, but also contributes to precision medicine by increasing measurement accuracy of scales.
The aims of this thesis were twofold. The first objective was to apply Rasch analysis to evaluate the performance of the Cumulative Illness Rating Scale (CIRS), Rivermead Postconcussion Questionnaire (RPQ), as well as the WHO Quality of Life Questionnaire-BREF (WHOQoL-BREF) and its shorter derivatives in TBI and orthopaedic populations. The second objective was to develop and test a conceptual and empirically-derived model that illustrates the structural relationships between the presence of comorbidities and injury characteristics, and their impact on PCS symptoms and quality of life in TBI and orthopaedic samples. These study aims were achieved using an age-sex matched case-control sample consisting of n=109 TBI and n=114 orthopaedic patients recruited from the Midland Trauma Registry in the Waikato district of New Zealand. Participants were assessed via telephone interviews regarding their health history, ongoing symptoms and current quality of life at six months to six years post-injury.
Results from the first study using Rasch analysis demonstrated that the RPQ and WHOQoL-BREF scales are reliable and unidimensional measures of persistent postconcussion symptoms and quality of life, respectively, that can be used for assessment in individuals with either TBI or orthopaedic injuries. Shorter versions such as the EUROHIS-QOL-8 and the development of a new 12-item WHOQoL version were also shown to be reliable measures especially useful in time-restrained settings, or where minimising respondent burden is a priority.
In the second study, multivariate linear regression identified that individuals with TBI or orthopaedic injuries, and with a history of neurological or psychiatric problems were at increased risk of reporting prolonged PCS symptoms and diminished quality of life. Findings from structural equation modelling also revealed that the persistence of post-injury psychological, neurological and musculoskeletal difficulties influenced long-term symptoms and quality of life in both groups. Previous research has misattributed PCS symptoms to the presence of a TBI, whereas a notable finding arising from these findings is that these symptoms are a significant predictor of post-injury quality of life in TBI and orthopaedic patients alike.
This thesis has made practical contributions to psychometric research, adhering to best practice guidelines with the provision of ordinal-to-interval conversion tables for improving clinical assessment. The development of a conceptual model that highlights the impact of comorbidities on injury outcomes serves as an important prognostic tool that can be useful for clinicians to identify high-risk individuals who are likely to have persisting difficulties. Prognostic modelling can therefore enable rehabilitation practitioners to modify treatment and tailor rehabilitation strategies from an early stage according to a patient’s individual needs
The geography of diabetes in Auckland: the influence of the socio-spatial environment on the prevalence of diabetes
No full textFull text is available to authenticated members of The University of Auckland only.Introduction Type 2 diabetes is one of the most common non-communicable diseases in New Zealand. Approximately 176,000 people in New Zealand (5% of adults) have been diagnosed with diabetes, and rates have increased over the last 15 years. Diabetes is known to vary by age group, ethnicity, area-deprivation, District Health Board (DHB) and across geographical regions. However few studies from New Zealand and internationally have investigated the influence the socio-spatial environment has on the prevalence of diabetes. Aims This thesis first investigates the prevalence of type 2 diabetes in Auckland Region, by sociodemographic determinants (age, gender, ethnicity, deprivation), and geographically by Census Area Unit (CAU), Territorial Authority (TA) and District Health Board (DHB). Second, this thesis aims to determine the association between diabetes prevalence and two socio-spatial determinants: access to unhealthy foods and recreational facilities in neighbourhoods. Method Using encrypted National Health Identifiers, data from the Primary Health Organisation (PHO) Enrolment Dataset and the National Minimum Dataset (NMDS) were linked to identify patients diagnosed with type 2 diabetes. For inclusion into the study, participants had to be aged 30 years and above, be enrolled in an Auckland Region PHO between 1 July and 30 September 2011. Additionally, patients had to have complete demographic, residential neighbourhood (census Meshblock), and type 2 diabetes status information. Measurement of the socio-spatial environment focussed on neighbourhood accessibility to unhealthy food outlets and recreational facilities at Meshblock level. Locality information of unhealthy food outlets and recreational facilities were obtained from the Zenbu directory of businesses in New Zealand. Accessibility was based on travel distance (metres) from population weighted centroids of Meshblocks to destinations with 1,000m for food outlets and 1,500 for recreational facilities. Levels of accessibility were indexed into quintiles from quintile 1 (low access) to quintile 5 (high access). Poisson regression analyses were conducted to investigate a patient’s likelihood of having diabetes, controlling for demographic and socio-spatial determinants and results were presented as Incidence Rate Ratios (IRRs) and 95% confidence intervals (CI). Findings This thesis used a study population of 746,568 participants, from which 63,761 patients were identified as having type 2 diabetes (9% prevalence for the Auckland region). After controlling for socio-demographic and socio-spatial factors, females in the study population were 13% less likely to have diabetes (IRR 0.87; 95% CI 0.86-0.88) than males. The likelihood of diabetes increased with age, peaking among those aged 75-79 years. Compared with the people aged 55-64 years, participants aged 30-34 years were 82% less likely (IRR 0.18; 95% CI 0.17-0.19), to have diabetes while participants aged 75-79 years were 61% more likely to have diabetes (IRR 1.61; 95% CI 1.56-1.65). Indian (IRR 3.48; 95% CI 3.39-3.58), Pacific Island (IRR 3.31; 95% CI 3.23-3.39) and Māori (IRR 2.37; 95% CI 2.29-2.45) participants were significantly more likely than the New Zealand/Other ethnic group to have diabetes. There were increasing IRRs across the New Zealand Index of Deprivation (NZDep 2006) quintiles, with the most deprived areas (quintile 5) having nearly twice the likelihood of diabetes (IRR 1.92; 95% CI 1.86-1.99) than residents living in least deprived areas. Across DHBs, residents of Counties Manukau DHB portrayed a 10% higher likelihood for diabetes (IRR 1.09; 95%CI 1.06-1.12) than residents of Auckland DHB, whereas no statistically significant differences were observed for Waitemata DHB. A similar burden of diabetes was evident at the TA level. Controlling for socio-demographic and socio-spatial factors, neighbourhoods with high accessibility to unhealthy foods were associated with 30% lower likelihood for diabetes (IRR 0.70; 95%CI 0.64- 0.77), however there was no statistically significant association between accessibility to recreational facilities and diabetes prevalence. Conclusion This thesis found increased risk for diabetes among participants aged 65 years and older, Maori, Pacific and Indian groups and for people living in the most deprived neighbourhoods of Auckland. Additionally, the thesis observed differences in diabetes rates, across geographical regions at the level of MB, CAU, TA ad DHB. This was the first study in New Zealand to investigate the association between the socio-spatial environment and diabetes. Surprisingly, there was a negative association between diabetes and increased neighbourhood accessibility to unhealthy food outlets. The need for a routinely updated is overdue in New Zealand and this thesis calls for urgent need to develop a routine diabetes register in New Zealand. Other key recommendations proposed in this thesis include improving geographic identifiers in health datasets and improving resources for physical activity opportunities in areas of high need
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Is the Rivermead Post-Concussion Symptoms Questionnaire a reliable and valid measure to assess long-term symptoms in traumatic brain injury and orthopedic injury patients? A novel investigation using Rasch analysis
Get PDFPersistent post-concussion syndrome (PCS) symptoms are known to last years after traumatic brain injury (TBI), and similar symptoms are increasingly being documented among those who have not experienced a TBI. There remains however, a dearth of empirical evidence on the structural composition of symptoms beyond the postacute symptom phase after TBI, and little is known about the potential use of PCS symptom scales to measure PCS-like symptoms in non-TBI individuals. Our objective was therefore to examine the psychometric performance and dimensionality of the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) as a measure of long-term PCS symptoms among a TBI and non-TBI sample. A case-control sample of 223 patients with injury, consisting of age- and sex-matched TBI participants (n = 109) and orthopedic participants (n = 114) were recruited from a regional trauma registry in New Zealand (NZ), and assessed at mean 2.5 years post-injury. Results from the Rasch analysis showed that the RPQ achieved fit to the Rasch model, demonstrating very good reliability (Person Separation Index [PSI] = 0.87), thereby indicating that the measure can be used reliably for individual and group assessment of symptoms among both TBI and orthopedic patients. In this study we demonstrated evidence of a unidimensional construct of PCS symptoms in both groups, which helps alleviate previous uncertainty about factor structure, and permits the calculation of a total RPQ score. Conversion of ordinal to interval total scores presented within are recommended for clinicians and researchers, to improve instrument precision, and to facilitate the interpretation of change scores and use of parametric methods in data analysis
- …
