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Search Results: 1 - 10 of 835 matches for " Gillian Lancaster "
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Peer Pressure and Family Smoking Habits Influence Smoking Uptake in Teenage Boys Attending School: Multilevel Modeling of Survey Data  [PDF]
Shafquat Rozi, Sadia Mahmud, Gillian Lancaster, Nida Zahid
Open Journal of Epidemiology (OJEpi) , 2016, DOI: 10.4236/ojepi.2016.63018
Abstract: Introduction: Among young teens, about one in five smokes worldwide. Adolescents spend a considerable amount of their time in school, and the school environment is therefore important for child health practices and outcomes. Objectives: We aimed to investigate the impact on smoking behavior of the school environment and the personal characteristics of male teenage students attending schools in Pakistan, taking into account the survey sampling structure. Methods: A two-stage cluster sampling with stratification was employed, and we interviewed 772 male secondary school students. We adopted random effect and generalizing estimating equation models. Results: Peer pressure in particular had a strong influence on adolescents smoking; those whose friends smoked were up to 6 times more likely to smoke. Family smoking was also significantly associated with adolescents smoking, but those students whose mother was educated were 50% less likely to smoke. The fitted random effect model indicated that the between school variability was significant (p-value < 0.01), indicating differences in smoking habits between schools. A random coefficient model showed that variability among schools was not significantly different for public and private schools. Conclusion: Public health campaigns for smoking cessation should target not only the individual but also the families of adolescents attending schools.
Multilevel Modeling of Binary Outcomes with Three-Level Complex Health Survey Data  [PDF]
Shafquat Rozi, Sadia Mahmud, Gillian Lancaster, Wilbur Hadden, Gregory Pappas
Open Journal of Epidemiology (OJEpi) , 2017, DOI: 10.4236/ojepi.2017.71004
Abstract: Complex survey designs often involve unequal selection probabilities of clus-ters or units within clusters. When estimating models for complex survey data, scaled weights are incorporated into the likelihood, producing a pseudo likeli-hood. In a 3-level weighted analysis for a binary outcome, we implemented two methods for scaling the sampling weights in the National Health Survey of Pa-kistan (NHSP). For NHSP with health care utilization as a binary outcome we found age, gender, household (HH) goods, urban/rural status, community de-velopment index, province and marital status as significant predictors of health care utilization (p-value < 0.05). The variance of the random intercepts using scaling method 1 is estimated as 0.0961 (standard error 0.0339) for PSU level, and 0.2726 (standard error 0.0995) for household level respectively. Both esti-mates are significantly different from zero (p-value < 0.05) and indicate consid-erable heterogeneity in health care utilization with respect to households and PSUs. The results of the NHSP data analysis showed that all three analyses, weighted (two scaling methods) and un-weighted, converged to almost identical results with few exceptions. This may have occurred because of the large num-ber of 3rd and 2nd level clusters and relatively small ICC. We performed a sim-ulation study to assess the effect of varying prevalence and intra-class correla-tion coefficients (ICCs) on bias of fixed effect parameters and variance components of a multilevel pseudo maximum likelihood (weighted) analysis. The simulation results showed that the performance of the scaled weighted estimators is satisfactory for both scaling methods. Incorporating simulation into the analysis of complex multilevel surveys allows the integrity of the results to be tested and is recommended as good practice.
Breast asymmetry and predisposition to breast cancer
Diane Scutt, Gillian A Lancaster, John T Manning
Breast Cancer Research , 2006, DOI: 10.1186/bcr1388
Abstract: In the present study, we compared the breast asymmetry of women who were free of breast disease at time of mammography, but who had subsequently developed breast cancer, with that of age-matched healthy controls who had remained disease-free to time of the present study. The study group consisted of 252 asymptomatic women who had normal mammography, but went on to develop breast cancer. The control group were 252 age-matched healthy controls whose mammograms were also normal and who remained free of cancer during the study period. Breast volume was calculated from the cranio-caudal mammograms for each group, and the relationships between asymmetry, established risk factors and the presence or absence of breast cancer were explored.The group who went on to develop breast cancer had higher breast asymmetry than controls (absolute asymmetry odds ratio 1.50 per 100 ml, confidence interval (CI) 1.10, 2.04; relative asymmetry 1.09, CI 1.01, 1.18), increased incidence of family history of breast cancer, lower age at menarche, later menopause, later first pregnancies and a higher frequency of high risk breast parenchyma types. Conditional logistic regression analysis showed that breast asymmetry, height, family history of breast cancer, age at menarche, parenchyma type and menopausal status were significant independent predictors of breast cancer. When age at menopause was included in the model for the subgroup of post-menopausal women, absolute breast fluctuating asymmetry (FA) and relative breast FA remained significant effects.Breast asymmetry was greater in healthy women who later developed breast cancer than in women who did not.Humans, in common with most other vertebrates, show bilateral symmetry in paired morphological traits such as ear size, digit length and breast volume. Perfect symmetry may be disturbed by a number of intrinsic and extrinsic factors, including the secretion of hormones such as oestrogen [1,2]. The small, random deviations from perfect symmetry
What is a pilot or feasibility study? A review of current practice and editorial policy
Mubashir Arain, Michael J Campbell, Cindy L Cooper, Gillian A Lancaster
BMC Medical Research Methodology , 2010, DOI: 10.1186/1471-2288-10-67
Abstract: Papers from 2007-08 in seven medical journals were screened to retrieve published pilot studies. Reports of registered and completed studies on the UK Clinical Research Network (UKCRN) Portfolio database were retrieved and scrutinized. Guidance on the conduct and reporting of pilot studies was retrieved from the websites of three grant giving bodies and seven journal editors were canvassed.54 pilot or feasibility studies published in 2007-8 were found, of which 26 (48%) were pilot studies of interventions and the remainder feasibility studies. The majority incorporated hypothesis-testing (81%), a control arm (69%) and a randomization procedure (62%). Most (81%) pointed towards the need for further research. Only 8 out of 90 pilot studies identified by the earlier review led to subsequent main studies. Twelve studies which were interventional pilot/feasibility studies and which included testing of some component of the research process were identified through the UKCRN Portfolio database. There was no clear distinction in use of the terms 'pilot' and 'feasibility'. Five journal editors replied to our entreaty. In general they were loathe to publish studies described as 'pilot'.Pilot studies are still poorly reported, with inappropriate emphasis on hypothesis-testing. Authors should be aware of the different requirements of pilot studies, feasibility studies and main studies and report them appropriately. Authors should be explicit as to the purpose of a pilot study. The definitions of feasibility and pilot studies vary and we make proposals here to clarify terminology.A brief definition is that a pilot study is a 'small study for helping to design a further confirmatory study'[1]. A very useful discussion of exactly what is a pilot study has been given by Thabane et al. [2] Such kinds of study may have various purposes such as testing study procedures, validity of tools, estimation of the recruitment rate, and estimation of parameters such as the variance of the outc
A Systematic Review of Observational Studies, Demonstrating Smoking among School Going Adolescents  [PDF]
Shafquat Rozi, Gillian Lancaster, Sadia Mahmud, Zahid Ahmad Butt, Talat Roome, Nida Zahid
Open Journal of Epidemiology (OJEpi) , 2019, DOI: 10.4236/ojepi.2019.92015
Abstract: Objective: To characterize the methods of design and analysis currently adopted in survey research of school-based observational studies for smoking, and to identify the common pitfalls made by researchers. Methods: The systematic review was conducted in 2009 and consisted of observational studies in school settings published between January 2005 and January 2009. Smoking status was the main outcome of interest. Following Cochrane style, five steps were followed: setting selection criteria for studies and conducting a literature search; review of abstracts; review of complete articles; data extraction and quality assessment of included studies; and, finally, synthesis of studies. Results: Of the 292 abstracts retrieved, 45 (15.4%) articles were selected for the final review. Inconsistencies were found in the definition of smoking behaviour which impeded generalisability. Individual-level factors had importance, but environmental level factors were also important in studying the aetiology of smoking. Results showed that studies inappropriately reported sample size estimation and important confounding factors. Hierarchical linear modelling, random effects modelling and structural equation modelling were employed in comparatively few studies. Conclusions: There were concerns regarding data analysis of complex surveys. Fifty five percent of reviewed studies ignored environmental effects which may have produced unreliable inferences. Multi-level analysis assisted in understanding school-level effects.
Land of a Couple of Dances: Global and Local Influences on Freestyle Play in Dance Dance Revolution
Gillian
Fibreculture Journal , 2006,
Abstract: This paper traces successful and unsuccessful attempts to shape the meanings of the video game Dance Dance Revolution, specifically with reference to what "dancing" means in this context, as the game moves between various interested parties - game developers, players, Internet forum participants, and other media producers. Drawing on Actor-Network Theory and the network analyses of Manuel Castells, the paper reconstructs the forces shaping players' stylistic decisions through an analysis of dance game machines and software, and of a single forum thread on DDRFreak.com, a major website in the dance game community. The paper asks who decides how DDR players dance and at what times? Are the decisions about play made in the development meeting, the arcade, competitions, online or around the home console? Globally, how do some regions or groups emerge as experts or leaders in play style? Analysis indicates that within the United States, Californian players from major cities dominate discussion, supported by the global flows of people, resources, and capital through the state. The dominant players support their stated norms for play through recourse to mainstream conceptions of masculinity, rap music and associated styles of dance.
The Malawi Developmental Assessment Tool (MDAT): The Creation, Validation, and Reliability of a Tool to Assess Child Development in Rural African Settings
Melissa Gladstone ,Gillian A. Lancaster,Eric Umar,Maggie Nyirenda,Edith Kayira,Nynke R. van den Broek,Rosalind L. Smyth
PLOS Medicine , 2010, DOI: 10.1371/journal.pmed.1000273
Abstract: Background Although 80% of children with disabilities live in developing countries, there are few culturally appropriate developmental assessment tools available for these settings. Often tools from the West provide misleading findings in different cultural settings, where some items are unfamiliar and reference values are different from those of Western populations. Methods and Findings Following preliminary and qualitative studies, we produced a draft developmental assessment tool with 162 items in four domains of development. After face and content validity testing and piloting, we expanded the draft tool to 185 items. We then assessed 1,426 normal rural children aged 0–6 y from rural Malawi and derived age-standardized norms for all items. We examined performance of items using logistic regression and reliability using kappa statistics. We then considered all items at a consensus meeting and removed those performing badly and those that were unnecessary or difficult to administer, leaving 136 items in the final Malawi Developmental Assessment Tool (MDAT). We validated the tool by comparing age-matched normal children with those with malnutrition (120) and neurodisabilities (80). Reliability was good for items remaining with 94%–100% of items scoring kappas >0.4 for interobserver immediate, delayed, and intra-observer testing. We demonstrated significant differences in overall mean scores (and individual domain scores) for children with neurodisabilities (35 versus 99 [p<0.001]) when compared to normal children. Using a pass/fail technique similar to the Denver II, 3% of children with neurodisabilities passed in comparison to 82% of normal children, demonstrating good sensitivity (97%) and specificity (82%). Overall mean scores of children with malnutrition (weight for height <80%) were also significantly different from scores of normal controls (62.5 versus 77.4 [p<0.001]); scores in the separate domains, excluding social development, also differed between malnourished children and controls. In terms of pass/fail, 28% of malnourished children versus 94% of controls passed the test overall. Conclusions A culturally relevant developmental assessment tool, the MDAT, has been created for use in African settings and shows good reliability, validity, and sensitivity for identification of children with neurodisabilities. Please see later in the article for the Editors' Summary
Another One Bites the Dust
David Lancaster
International Journal of Motorcycle Studies , 2009,
Abstract:
The Cognitive Neuroscience of Consciousness, Mysticism and Psi
Les Lancaster
International Journal of Transpersonal Studies , 2011,
Abstract: The greatest contemporary challenge in the arena of cognitive neuroscience concerns the relation between consciousness and the brain. Over recent years the focus of work in this area has switched from the analysis of diverse spatial regions of the brain to that of the timing of neural events. It appears that two conditions are necessary in order for neural events to become correlated with conscious experience. First, the firing of assemblies ofneurones must achieve a degree of coherence, and, second, reflexive (i.e. top-down, or reentrant)neural pathways must be activated. It does not, of course, follow that such neural activity causes consciousness; it may be, for example, that the neural activity formats the brain to interact with consciousness. The latter possibility is suggested by analysis of mystical texts suggesting that coherence and reflexivity constitute the conditions for the influx of “spirit.” Kabbalistic sources, for example, describe a hierarchy of “brains” in the human and divine realms through which the principles of coherence and reflexivity operate. Whilst theontological assumptions of such a scheme place it beyond the realm of psychology, parallels with the picture deriving from the contemporary cognitive neuroscience of consciousness are striking.
Bortezomib: the evidence of its clinical impact in multiple myeloma
Simon Lancaster
Core Evidence , 2006,
Abstract: Simon LancasterSL Comm Ltd, Macclesfield, UKIntroduction: Multiple myeloma is a relatively common and incurable form of hematologic malignancy for which there is currently no single standard therapy. Bortezomib inhibits the 20S proteasome involved in the degradation of intracellular proteins, induces apoptosis, reverses drug resistance in multiple myeloma cells, and influences their microenvironment by blocking cytokine circuits, cell adhesion and angiogenesis in vivo.Aims: The objective of this review is to evaluate the evidence for the use of bortezomib in the treatment of multiple myeloma.Evidence review: In patients with relapsed multiple myeloma bortezomib significantly prolongs overall survival and time to progression, and improves response rates, duration of response, and quality of life compared with oral high-dose dexamethasone. Although the incidence of grade 4 adverse events was similar, grade 3 events and herpes zoster infections occur more frequently in patients treated with bortezomib than with high-dose dexamethasone. Evidence from a pharmacoeconomic study indicates that the benefits of bortezomib compared to thalidomide plus best standard care may be achieved at a reasonable cost.Clinical value: Bortezomib is a valuable treatment option in the management of relapsed multiple myeloma that improves survival and delays disease progression compared with oral high-dose dexamethasone treatment, albeit with an increased incidence of some adverse events such as grade 3 thrombocytopenia and neutropenia.Key words: bortezomib, evidence, multiple myeloma, outcomes, treatment
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