Showing papers by "University of Aberdeen published in 2004"

Effectiveness and efficiency of guideline dissemination and implementation strategies

Abstract: OBJECTIVES: To undertake a systematic review of the effectiveness and costs of different guideline development, dissemination and implementation strategies. To estimate the resource implications of these strategies. To develop a framework for deciding when it is efficient to develop and introduce clinical guidelines. DATA SOURCES: MEDLINE, Healthstar, Cochrane Controlled Trial Register, EMBASE, SIGLE and the specialised register of the Cochrane Effective Practice and Organisation of Care (EPOC) group. REVIEW METHODS: Single estimates of dichotomous process variables were derived for each study comparison based upon the primary end-point or the median measure across several reported end-points. Separate analyses were undertaken for comparisons of different types of intervention. The study also explored whether the effects of multifaceted interventions increased with the number of intervention components. Studies reporting economic data were also critically appraised. A survey to estimate the feasibility and likely resource requirements of guideline dissemination and implementation strategies in UK settings was carried out with key informants from primary and secondary care. RESULTS: In total, 235 studies reporting 309 comparisons met the inclusion criteria; of these 73% of comparisons evaluated multifaceted interventions, although the maximum number of replications of a specific multifaceted intervention was 11 comparisons. Overall, the majority of comparisons reporting dichotomous process data observed improvements in care; however, there was considerable variation in the observed effects both within and across interventions. Commonly evaluated single interventions were reminders, dissemination of educational materials, and audit and feedback. There were 23 comparisons of multifaceted interventions involving educational outreach. The majority of interventions observed modest to moderate improvements in care. No relationship was found between the number of component interventions and the effects of multifaceted interventions. Only 29.4% of comparisons reported any economic data. The majority of studies only reported costs of treatment; only 25 studies reported data on the costs of guideline development or guideline dissemination and implementation. The majority of studies used process measures for their primary end-point, despite the fact that only three guidelines were explicitly evidence based (and may not have been efficient). Respondents to the key informant survey rarely identified existing budgets to support guideline dissemination and implementation strategies. In general, the respondents thought that only dissemination of educational materials and short (lunchtime) educational meetings were generally feasible within current resources. CONCLUSIONS: There is an imperfect evidence base to support decisions about which guideline dissemination and implementation strategies are likely to be efficient under different circumstances. Decision makers need to use considerable judgement about how best to use the limited resources they have for clinical governance and related activities to maximise population benefits. They need to consider the potential clinical areas for clinical effectiveness activities, the likely benefits and costs required to introduce guidelines and the likely benefits and costs as a result of any changes in provider behaviour. Further research is required to: develop and validate a coherent theoretical framework of health professional and organisational behaviour and behaviour change to inform better the choice of interventions in research and service settings, and to estimate the efficiency of dissemination and implementation strategies in the presence of different barriers and effect modifiers.

CONSORT statement: extension to cluster randomised trials

Abstract: The Consolidated Standards of Reporting Trials (CONSORT) statement was developed to improve the reporting of randomised controlled trials. It was initially published in 1996 and focused on the reporting of parallel group randomised controlled trials. The statement was revised in 2001, with a further update in 2010. A separate CONSORT statement for the reporting of abstracts was published in 2008. In earlier papers we considered the implications of the 2001 version of the CONSORT statement for the reporting of cluster randomised trial. In this paper we provide updated and extended guidance, based on the 2010 version of the CONSORT statement and the 2008 CONSORT statement for the reporting of abstracts.

The positive and negative affect schedule (PANAS): construct validity, measurement properties and normative data in a large non-clinical sample.

Abstract: Objectives: To evaluate the reliability and validity of the PANAS (Watson, Clark, & Tellegen, 1988b) and provide normative data. Design: Cross-sectional and correlational. Method: The PANAS was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,003). Competing models of the latent structure of the PANAS were evaluated using confirmatory factor analysis. Regression and correlational analysis were used to determine the influence of demographic variables on PANAS scores as well as the relationship between the PANAS with measures of depression and anxiety (the HADS and the DASS). Results: The best-fitting model (robust comparative fit index = .94) of the latent structure of the PANAS consisted of two correlated factors corresponding to the PA and NA scales, and permitted correlated error between items drawn from the same mood subcategories (Zevon & Tellegen, 1982). Demographic variables had only very modest influences on PANAS scores and the PANAS exhibited measurement invariance across demographic subgroups. The reliability of the PANAS was high, and the pattern of relationships between the PANAS and the DASS and HADS were consistent with tripartite theory. Conclusion: The PANAS is a reliable and valid measure of the constructs it was intended to assess, although the hypothesis of complete independence between PA and NA must be rejected. The utility of this measure is enhanced by the provision of large-scale normative data.

Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations.

Abstract: The Movement Disorder Society Task Force for Rating Scales for Parkinson's disease (PD) prepared a critique of the Hoehn and Yahr scale (HY). Strengths of the HY scale include its wide utilization and acceptance. Progressively higher stages correlate with neuroimaging studies of dopaminergic loss, and high correlations exist between the HY scale and some standardized scales of motor impairment, disability, and quality of life. Weaknesses include the scale's mixing of impairment and disability and its non-linearity. Because the HY scale is weighted heavily toward postural instability as the primary index of disease severity, it does not capture completely impairments or disability from other motor features of PD and gives no information on nonmotor problems. Direct clinimetric testing of the HY scale has been very limited, but the scale fulfills at least some criteria for reliability and validity, especially for the midranges of the scale (Stages 2-4). Although a "modified HY scale" that includes 0.5 increments has been adopted widely, no clinimetric data are available on this adaptation. The Task Force recommends that: (1) the HY scale be used in its original form for demographic presentation of patient groups; (2) when the HY scale is used for group description, medians and ranges should be reported and analysis of changes should use nonparametric methods; (3) in research settings, the HY scale is useful primarily for defining inclusion/exclusion criteria; (4) to retain simplicity, clinicians should "rate what you see" and therefore incorporate comorbidities when assigning a HY stage; and (5) because of the wide usage of the modified HY scale with 0.5 increments, this adaptation warrants clinimetric testing. Without such testing, however, the original five-point scales should be maintained.

Item Response Theory for Psychologists

Abstract: classical test theory amp item response theory study june 24th, 2018 psychometrics is the study of developing tests and measurements in this lesson we ll talk about two different theories of how psychologists can create good tests and measurement classical test theory and item response theory' 'The Theory and Practice of Item Response Theory December 31st, 2008 The Theory and Practice of Item Response Theory Methodology in the Social Sciences R J de Ayala on FREE shipping on qualifying offers margin 0pt gt Item response theory IRT is a latent variable modeling approach used to minimize bias and optimize the measurement power of educational and psychological tests and other' 'Learning theory psychology Britannica June 24th, 2018 Learning theory Learning theory any of the proposals put forth to explain changes in behaviour produced by practice as opposed to other factors e g physiological development' ' ITEM RESPONSE THEORY FOR PSYCHOLOGISTS MAY 2ND, 2000 ITEM RESPONSE THEORY FOR PSYCHOLOGISTS MULTIVARIATE APPLICATIONS SERIES 9780805828191 SUSAN E EMBRETSON STEVEN P REISE BOOKS'' Personality Project s Guide to R June 22nd, 2018 Using R for psychological research A simple guide to an elegant language This is one page of a series of tutorials for using R in psychological '

Constructing questionnaires based on the theory of planned behaviour: A manual for health services researchers

Abstract: Copyright & reuse City University London has developed City Research Online so that its users may access the research outputs of City University London's staff. Copyright © and Moral Rights for this paper are retained by the individual author(s) and/ or other copyright holders. All material in City Research Online is checked for eligibility for copyright before being made available in the live archive. URLs from City Research Online may be freely distributed and linked to from other web pages.

Systematic review of the long-term effects and economic consequences of treatments for obesity and implications for health improvement

Abstract: Objectives To undertake a systematic review of the long-term effects of obesity treatments on body weight, risk factors for disease, and disease. Methods The study encompassed three systematic reviews that examined different aspects of obesity treatments. (1) A systematic review of obesity treatments in adults where the methods of the Cochrane Collaboration were applied and randomised controlled trials (RCTs) with a follow-up of at least 1 year were evaluated. (2) A systematic epidemiological review, where studies were sought on long-term effects of weight loss on morbidity and/or mortality, and examined through epidemiological modelling. (3) A systematic economic review that sought reports with both costs and outcomes of treatment, including recent reports that assessed the cost-effectiveness of pharmaceutical and surgical interventions. A Markov model was also adopted to examine the cost-effectiveness of a low-fat diet and exercise intervention in adults with obesity and impaired glucose tolerance. Results The addition of the drugs orlistat or sibutramine was associated with weight loss and generally improved risk factors, apart from diastolic blood pressure for sibutramine. Metformin was associated with decreased mortality after 10 years in obese people with type 2 diabetes. Low-fat diets were associated with continuing weight loss for 3 years and improvements in risk factors, as well as prevention of type 2 diabetes and improved control of hypertension. Insufficient evidence was available to demonstrate the benefits of low calorie or very low calorie diets. The addition of an exercise or behaviour programme to diet was associated with improved weight loss and risk factors for at least 1 year. Studies combining low-fat diets, exercise and behaviour therapy suggested improved hypertension and cardiovascular disease. Family therapy was associated with improved weight loss for 2 years compared to individual therapy. There was insufficient evidence to conclude that individual therapy was more beneficial than group therapy. Weight lost more quickly (within 1 year), from the epidemiology review, may be more beneficial with respect to the risk of mortality. The effects of intentional weight loss need further investigation. Weight loss from surgical and non-surgical interventions for people suffering from obesity was associated with decreased risk of development of diabetes, and a reduction in low-density lipoprotein cholesterol, total cholesterol and blood pressure, in the long term. Targeting high-risk individuals with drugs or surgery was likely to result in a cost per additional life-year or quality-adjusted life-year (QALY) of no more than 13,000 British pounds. There was also suggestive evidence of cost saving from treatment of people with type 2 diabetes with metformin. Targeting surgery on people with severe obesity and impaired glucose tolerance was likely to be more cost-effective at 2329 British pounds per additional life-year. Economic modelling over 6 years for diet and exercise for people with impaired glucose tolerance was associated with a high initial cost per additional QALY, but by the sixth year the cost per QALY was 13,389 British pounds. Results did not include cost savings from diseases other than diabetes, and therefore may be conservative. Conclusions The drugs orlistat and sibutramine appear beneficial for the treatment of adults with obesity, and metformin for obese patients with type 2 diabetes. Exercise and/or behaviour therapy appear to improve weight loss when added to diet. Low-fat diets with exercise, or with exercise and behaviour therapy are associated with the prevention of type 2 diabetes and hypertension. Long-term weight loss in epidemiological studies was associated with reduced risk of type 2 diabetes, and may be beneficial for cardiovascular disease. Low-fat diets and exercise interventions in individuals at risk of obesity-related illness are of comparable cost to drug treatments. Long-term pragmatic RCTs of obesity treatments in populations with obesity-related illness or at high risk of developing such illness are needed (to include an evaluation of risk factors, morbidity, quality of life and economic evaluations). Drug trials that include dietary advice, plus exercise and/or behaviour therapy are also needed. Research exploring effective types of exercise, diet or behaviour and also interventions to prevent obesity in adults is required.

Epidemiology of preterm birth

Abstract: Preterm birth is a major challenge in perinatal health care. Most perinatal deaths occur in preterm infants, and preterm birth is an important risk factor for neurological impairment and disability. Preterm birth not only affects infants and their families—providing care for preterm infants, who may spend several months in hospital, has increasing cost implications for health services. Preterm birth is the delivery of a baby before 37 completed weeks' gestation. Most mortality and morbidity affects “very preterm” infants (those born before 32 weeks' gestation), and especially “extremely preterm” infants (those born before 28 weeks of gestation). Definitions of preterm live births by completed weeks of gestation Over the past 20-30 years advances in perinatal care have improved outcomes for infants born after short gestations. The number of weeks of completed gestation that defines whether a birth is preterm rather than a fetal loss has become smaller. In 1992 the boundary that required registration as a preterm live birth in the United Kingdom was lowered from 28 completed weeks' gestation to 24 weeks' gestation. This boundary varies internationally, however, from about 20 to 24 weeks. Some classification of fetal loss, still birth, and early neonatal death for these very short gestations may be unreliable. Even in developed countries, there is often uncertainty and incomplete recording of estimates of gestation. In most of the United Kingdom data on birth weight data but not on gestational age are collected routinely. Although some concordance exists between the categories of birth weight and gestational age, they are not interchangeable. The categories for birth weight are: Only around two thirds of …

The impact of childhood intelligence on later life: following up the Scottish mental surveys of 1932 and 1947.

Abstract: The Scottish Mental Surveys of 1932 and 1947 collected valid IQ-type test scores for almost everyone born in 1921 and 1936 and attending school on June 1, 1932 (N=89,498) and June 4, 1947 (N=70,805). These surveys are described. This research, using the surveys' data, examined (a) the stability of intelligence differences across the life span, (b) the determinants of cognitive change from childhood to old age, and (c) the impact of childhood intelligence on survival and health in old age. Surviving participants of the Scottish Mental Surveys were tested, and the surveys' data were linked with public and health records. Novel findings on the stability of IQ scores from age 11 to age 80; sex differences in cognitive aging; the dedifferentiation hypothesis of cognitive aging; and the effect of childhood IQ on all-cause and specific mortality, morbidity, and frailty in old age are presented.

Identifying the role that animals play in their social networks.

Abstract: Techniques recently developed for the analysis of human social networks are applied to the social network of bottlenose dolphins living in Doubtful Sound, New Zealand. We identify communities and subcommunities within the dolphin population and present evidence that sex– and age–related homophily play a role in the formation of clusters of preferred companionship. We also identify brokers who act as links between sub–communities and who appear to be crucial to the social cohesion of the population as a whole. The network is found to be similar to human social networks in some respects but different in some others, such as the level of assortative mixing by degree within the population. This difference elucidates some of the means by which the network forms and evolves.

Extinction and Ecosystem Function in the Marine Benthos

Abstract: Rapid changes in biodiversity are occurring globally, yet the ecological impacts of diversity loss are poorly understood. Here we use data from marine invertebrate communities to parameterize models that predict how extinctions will affect sediment bioturbation, a process vital to the persistence of aquatic communities. We show that species extinction is generally expected to reduce bioturbation, but the magnitude of reduction depends on how the functional traits of individual species covary with their risk of extinction. As a result, the particular cause of extinction and the order in which species are lost ultimately govern the ecosystem-level consequences of biodiversity loss.

A meta-analytic review of verbal fluency performance following focal cortical lesions.

Abstract: A meta-analysis of 31 studies with 1,791 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of focal cortical lesions Relative to healthy controls, participants with focal frontal injuries had large and comparable deficits on phonemic (r = 52) and semantic (r = 54) fluency For frontal but not nonfrontal patients, phonemic fluency deficits qualified as differential deficits when compared with IQ and psychomotor speed; phonemic fluency was also more strongly and more specifically related to the presence of frontal lesions than the Wisconsin Card Sorting Test scores In contrast, temporal damage was associated with a lesser deficit on phonemic fluency (r = 44) but a larger deficit on semantic fluency (r = 61)

A meta-analytic review of prospective memory and aging.

Abstract: A meta-analysis of prospective memory (PM) studies revealed that in laboratory settings younger participants outperform older participants on tests of both time- and event-based PM (rs .39 and .34, respectively). Event-based PM tasks that impose higher levels of controlled strategic demand are associated with significantly larger age effects than event-based PM tasks that are supported by relatively more automatic processes (rs .40 vs. .14, respectively). However, contrary to the prevailing view in the literature, retrospective memory as measured by free recall is associated with significantly greater age-related decline (r –.52) than PM, and older participants perform substantially better than their younger counterparts in naturalistic PM studies (rs .35 and .52 for event- and time-based PM, respectively). Much research on cognitive aging has focused on retrospective memory, or recollection of past events (for a review, see Light, 1991), and almost invariably it has been reported that substantial deficits in this aspect of cognition are associated with normal aging. However, interest has increasingly shifted to investigating prospective memory (PM), that is, memory for future intentions. Relative to retrospective memory, PM is believed to be more dependent on internal control mechanisms (Craik, 1983, 1986). This is because, according to Craik’s (1986) theoretical model, the act of recollection is dependent on reconstructing events in memory, and it is suggested that this process must be guided either by external cues, or in their absence, self-initiated cues. In retrospective memory tasks explicit prompts to recall are provided by the experimenter, whereas in PM tasks the cue is not an explicit request for action, but instead it requires either interpretation of a cue or an internal impetus. It has often been argued that this requirement for self-initiated remembering means that PM tasks should be more susceptible to the effects of adult aging than retrospective memory tasks (e.g., Craik, 1986; Maylor, 1995; McDaniel & Einstein, 2000).

A Systematic Review of Action Imitation in Autistic Spectrum Disorder

Abstract: Imitative deficits have been associated with autistic spectrum disorder (ASD) for many years, most recently through more robust methodologies. A fresh, systematic review of the significance, characteristics, and underlying mechanism of the association is therefore warranted. From 121 candidates, we focused on 21 well-controlled studies involving 281 cases of ASD. Overall, children with ASD performed worse on imitative tasks (Combined Logit p value < .00005). The emerging picture is of delayed development in imitation, implicating a deficit in mapping neural codings for actions between sensory and motor modalities, rather than in motivation or executive function. We hypothesise that ASD is characterised by abnormal development of these mappings, such that they are biased towards object-oriented tasks at the expense of those required for action imitation per se.

Uncoupled and surviving: individual mice with high metabolism have greater mitochondrial uncoupling and live longer

Abstract: Two theories of how energy metabolism should be associated with longevity, both mediated via free-radical production, make completely contrary predictions. The 'rate of living-free-radical theory' (Pearl, 1928; Harman, 1956; Sohal, 2002) suggests a negative association, the 'uncoupling to survive' hypothesis (Brand, 2000) suggests the correlation should be positive. Existing empirical data on this issue is contradictory and extremely confused (Rubner, 1908; Yan & Sohal, 2000; Ragland & Sohal, 1975; Daan et al., 1996; Wolf & Schmid-Hempel, 1989]. We sought associations between longevity and individual variations in energy metabolism in a cohort of outbred mice. We found a positive association between metabolic intensity (kJ daily food assimilation expressed as g/body mass) and lifespan, but no relationships of lifespan to body mass, fat mass or lean body mass. Mice in the upper quartile of metabolic intensities had greater resting oxygen consumption by 17% and lived 36% longer than mice in the lowest intensity quartile. Mitochondria isolated from the skeletal muscle of mice in the upper quartile had higher proton conductance than mitochondria from mice from the lowest quartile. The higher conductance was caused by higher levels of endogenous activators of proton leak through the adenine nucleotide translocase and uncoupling protein-3. Individuals with high metabolism were therefore more uncoupled, had greater resting and total daily energy expenditures and survived longest - supporting the 'uncoupling to survive' hypothesis.

Physiology of the endothelium

Abstract: In the past, the endothelium was considered to be inert, described as a 'layer of nucleated cellophane', with only non-reactive barrier properties, such as presentation of a non-thrombogenic surface for blood flow and guarding against pro-inflammatory insults. However, it is now becoming clear that endothelial cells actively and reactively participate in haemostasis and immune and inflammatory reactions. They regulate vascular tone via production of nitric oxide, endothelin and prostaglandins and are involved in the manifestations of atherogenesis, autoimmune diseases and infectious processes. They produce and react to various cytokines and adhesion molecules and it is now clear that they can mount anti- and pro-inflammatory and protective responses depending on environmental conditions and are key immunoreactive cells. Endothelial dysfunction or activation also contributes to a variety of disease states.

Culture on the Ground The World Perceived Through the Feet

Abstract: Classical accounts of human evolution posit a progressive differentiation between the hands as instruments of rational intelligence and feet as integral to the mechanics of bipedal locomotion. Yet evolutionists were modelling pedestrian performance on the striding gait of boot-clad Europeans. The bias of head over heels in their accounts follows a long-standing tendency, in western thought and science, to elevate the plane of social and cultural life over the ground of nature. This tendency was already established among European elites in the practice of destination-oriented travel, the use of shoes and chairs, and the valorization of upright posture. It was further reinforced in urban societies through paving the streets. The groundlessness of metropolitan life remains embedded not only in western social structures but also in the disciplines of anthropology, psychology and biology. A more grounded approach to human movement, sensitive to embodied skills of footwork, opens up new terrain in the study of ...

Cognition and Behavior in Two-Person Guessing Games: An Experimental Study

Abstract: "...professional investment may be likened to those newspaper competitions in which the competitors have to pick out the six prettiest faces from a hundred photographs, the prize being awarded to the competitor whose choice most nearly corresponds to the average preferences of the competitors as a whole; so that each competitor has to pick, not those faces which he himself finds prettiest, but those which he thinks likeliest to catch the fancy of the other competitors, all of whom are looking at the problem from the same point of view. It is not a case of choosing those which, to the best of one's judgment, are really the prettiest, nor even those which average opinion genuinely thinks the prettiest. We have reached the third degree where we devote our intelligences to anticipating what average opinion expects the average opinion to be. And there are some, I believe, who practice the fourth, fifth and higher degrees." - John Maynard Keynes, The General Theory of Employment, Interest, and Money This paper reports experiments that elicit subjects' initial responses to 16 dominance-solvable two-person guessing games. The structure is publicly announced except for varying payoff parameters, to which subjects are given free access, game by game, through an interface that records their information searches. Varying the parameters allows strong separation of the behavior implied by leading decision rules and makes monitoring search a powerful tool for studying cognition. Many subjects' decisions and searches show clearly that they understand the games and seek to maximize their payoffs, but have boundedly rational models of others' decisions, which lead to systematic deviations from equilibrium.

Epidemiology of diabetic retinopathy and macular oedema: a systematic review

Abstract: Aims To systematically review the literature on the prevalence and incidence of diabetic retinopathy (DR) and macular oedema (MO). Methods A search of the bibliographic databases (Medline, Embase, CINAHL) was conducted up to October 2001. Selected relevant studies were scrutinized and included in the review. Results A total of 359 studies were included. The studies were reported in nearly 100 different journals and in over 50 countries. The majority of the studies were US-based, with large studies such as the Wisconsin Epidemiologic Study of Diabetic Retinopathy dominating the literature. The studies were quite dated and highly heterogeneous in nature in terms of patient selection with variable inclusion criteria (age range, gender, diabetes duration and type, ethnicity, comorbidity, and DR status, assessment, and classification). Conclusions There are inconsistencies between epidemiological studies, and differences in study methods may contribute to conflicting reports of prevalence and incidence of DR and MO in diabetic populations. As new therapies for DR and its associated complications emerge, the need to capture and monitor new epidemiological data becomes increasingly important to be able to assess the impact and effectiveness of these therapies. Robust, longitudinal capture of patient data is, therefore, essential to evaluate the impact of current practice on the epidemiology of diabetic eye complications.

Identifying and training non-technical skills for teams in acute medicine

Abstract: The aviation domain provides a better analogy for the ’’temporary’’ teams that are found in acute medical specialities than industrial or military teamwork research based on established teams. Crew resource management (CRM) training, which emphasises portable skills (for whatever crew a pilot is rostered to on a given flight), has been recognised to have potential application in medicine, especially for teams in the operating theatre, intensive care unit, and emergency room. Drawing on research from aviation psychology that produced the behavioural marker system NOTECHS for rating European pilots’ non-technical skills for teamwork on the flightdeck, this paper outlines the Anaesthetists Non-Technical Skills behavioural rating system for anaesthetists working in operating theatre teams. This taxonomy was used as the design basis for a training course, Crisis Avoidance Resource Management for Anaesthetists used to develop these skills, based in an operating theatre simulator. Further developments of this training programme for teams in emergency medicine are outlined.

Patient compliance in hypertension: role of illness perceptions and treatment beliefs.

Abstract: Despite many years of study, questions remain about why patients do or do not take medicines and what can be done to change their behaviour. Hypertension is poorly controlled in the UK and poor compliance is one possible reason for this. Recent questionnaires based on the self-regulatory model have been successfully used to assess illness perceptions and beliefs about medicines. This study was designed to describe hypertensive patients' beliefs about their illness and medication using the self-regulatory model and investigate whether these beliefs influence compliance with antihypertensive medication. We recruited 514 patients from our secondary care population. These patients were asked to complete a questionnaire that included the Beliefs about Medicines and Illness Perception Questionnaires. A case note review was also undertaken. Analysis shows that patients who believe in the necessity of medication are more likely to be compliant (odds ratio (OR)) 3.06 (95% CI 1.74-5.38), P<0.001). Other important predictive factors in this population are age (OR 4.82 (2.85-8.15), P<0.001), emotional response to illness (OR 0.65 (0.47-0.90), P=0.01) and belief in personal ability to control illness (OR 0.59 (0.40-0.89), P=0.01). Beliefs about illness and about medicines are interconnected; aspects that are not directly related to compliance influence it indirectly. The self-regulatory model is useful in assessing patients health beliefs. Beliefs about specific medications and about hypertension are predictive of compliance. Information about health beliefs is important in achieving concordance and may be a target for intervention to improve compliance.

Polymorphisms in Genes Involved in Folate Metabolism and Colorectal Neoplasia: A HuGE Review

Abstract: Epidemiologic and mechanistic evidence suggests that folate is involved in colorectal neoplasia. Some polymorphic genes involved in folate metabolism--methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), methionine synthase reductase (MTRR A66G), cystathionine beta-synthase (CBS exon 8, 68-base-pair insertion), and thymidylate synthase (TS enhancer region and 3' untranslated region)--have been investigated in colorectal neoplasia. For MTHFR C677T and A1298C, the variant allele is associated with reduced enzyme activity in vitro. For the other polymorphisms, functional data are limited and/or inconsistent. Genotype frequencies for all of the polymorphisms show marked ethnic and geographic variation. In most studies, MTHFR 677TT (10 studies, >4,000 cases) and 1298CC (four studies, >1,500 cases) are associated with moderately reduced colorectal cancer risk. In four of five genotype-diet interaction studies, 677TT subjects who had higher folate levels (or a "high-methyl diet") had the lowest cancer risk. In two studies, 677TT homozygote subjects with the highest alcohol intake had the highest cancer risk. Findings from six studies of MTHFR C677T and adenomatous polyps are inconsistent. There have been only one or two studies of the other polymorphisms; replication is needed. Overall, the roles of folate-pathway genes, folate, and related dietary factors in colorectal neoplasia are complex. Research priorities are suggested.