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Biomedical subjects

A Britton

Publications and source records attributed to A Britton.

At least 19 recordsLinked to original sources
PubMed2004

Multidisciplinary team interventions for delirium in patients with chronic cognitive impairment.

BACKGROUND: Delirium is common in hospitalized elderly people. Delirium may affect 60% of frail elderly people in hospital. Among the cognitively impaired, 45% have been found to develop delirium and these patients have longer lengths of hospital stay and a higher rate of complications which, with other factors, increase costs of care. The management of delirium has commonly been multifaceted, the primary emphasis has to be on the diagnosis and therapy of precipitating factors, but as these may not be immediately resolved, symptomatic and supportive care are also of major importance. OBJECTIVES: The objective of this review is to assess the available evidence for the effectiveness, if any, of multidisciplinary team interventions in the coordinated care of elderly patients with delirium superimposed on an underlying chronic cognitive impairment in comparison with usual care. SEARCH STRATEGY: The trials were identified from a last updated search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 3 July 2003 using the terms delirium and confus*. The Register is regularly updated and contains records of all major health care databases and many ongoing trial databases. SELECTION CRITERIA: Selection for possible inclusion in this review was made on the basis of the research methodology - controlled trials whose participants are reported as having chronic cognitive impairment, and who then developed incident delirium and were randomly assigned to either coordinated multidisciplinary care or usual care. DATA COLLECTION AND ANALYSIS: Nine controlled trials were identified for possible inclusion in the review, only one of which met the inclusion criteria. At present the data from that study cannot be analysed. We have requested additional data from the authors and are awaiting their reply. MAIN RESULTS: No studies focused on patients with prior cognitive impairment, so management of delirium in this group could not be assessed. There is very little information on the management of delirium in the literature despite an increasing body of information about the incidence, risks and prognosis of the disorder in the elderly population. REVIEWERS' CONCLUSIONS: The management of delirium needs to be studied in a more clearly defined way before evidence-based guidelines can be developed. Insufficient data are available for the development of evidence-based guidelines on diagnosis or management. There is scope for research in all areas - from basic pathophysiology and epidemiology to prevention and management. Though much recent research has focused on the problem of delirium, the evidence is still difficult to utilize in management programmes. Research needs to be undertaken targeting specific groups known to be at high risk of developing delirium, for example the cognitively impaired and the frail elderly. As has been highlighted by Inouye 1999, delirium has very important economic and health policy implications and is a clinical problem that can affect all aspects of care of an ill older person.Delirium, though a frequent problem in hospitalized elderly patients, is still managed empirically and there is no evidence in the literature to support change to current practice at this time.

Aged↗
PubMed2004

Surface analysis and depth profiling of corrosion products formed in lead pipes used to supply low alkalinity drinking water.

Modern analytical techniques have been applied to investigate the nature of lead pipe corrosion products formed in pH adjusted, orthophosphate-treated, low alkalinity water, under supply conditions. Depth profiling and surface analysis have been carried out on pipe samples obtained from the water distribution system in Glasgow, Scotland, UK. X-ray diffraction spectrometry identified basic lead carbonate, lead oxide and lead phosphate as the principal components. Scanning electron microscopy/energy-dispersive x-ray spectrometry revealed the crystalline structure within the corrosion product and also showed spatial correlations existed between calcium, iron, lead, oxygen and phosphorus. Elemental profiling, conducted by means of secondary ion mass spectrometry (SIMS) and secondary neutrals mass spectrometry (SNMS) indicated that the corrosion product was not uniform with depth. However, no clear stratification was apparent. Indeed, counts obtained for carbonate, phosphate and oxide were well correlated within the depth range probed by SIMS. SNMS showed relationships existed between carbon, calcium, iron, and phosphorus within the bulk of the scale, as well as at the surface. SIMS imaging confirmed the relationship between calcium and lead and suggested there might also be an association between chloride and phosphorus.

Corrosion↗
PubMed2003

A comparison of the alcohol-attributable mortality in four European countries.

BACKGROUND: Deaths due to alcohol consumption are an important component of all-cause mortality, particularly premature mortality. However, there are considerable regional variations, the reasons for which are unclear. METHODS: Estimates were made as reliably as possibly using vital statistics and best estimates of risk of the alcohol-attributable mortality, by age, sex and cause for four European countries (England and Wales, Germany, Denmark and Italy). Twenty-seven alcohol-related conditions were considered including the possible cardio-protective effects of alcohol. RESULTS: It was estimated that there are approximately 2% fewer deaths annually in England and Wales than would be expected in a non-drinking population and 0.3% fewer deaths among East German females. In West Germany, Denmark, Italy and among East German males there are more deaths caused by alcohol than are prevented (between 0.7 and 2.6% of all deaths). The highest age-specific proportion of alcohol-attributable deaths is found in East Germany where around 30% of deaths among males aged 25-44 years are due to drinking. Among young men in all four countries the largest contributor to alcohol-related deaths is road traffic accidents involving alcohol. CONCLUSIONS: Possible explanations for the variation in alcohol-attributable deaths between countries include different underlying heart disease rates, different patterns of alcohol consumption and beverage preferences, and different use of mortality classification. Differences in the reported alcohol consumption levels explain little of the variation in alcohol-attributable deaths. Estimating alcohol-attributable mortality by age and sex across countries may be a useful indicator for developing alcohol strategies and exploring ways of preventing premature mortality.

Adolescent↗
PubMed2001

Curative resection for rectal carcinoma: definition influences outcome in terms of local recurrence.

OBJECTIVE: There are wide variations in local recurrence rate following curative surgery for rectal cancer and there are substantial inconsistencies among surgeons regarding the method of defining curative resection. This paper seeks to explore whether defining criteria is one of the important factors driving the variations in outcome. METHOD: A literature review was undertaken to find all UK-based studies that had data on curative resection and local recurrence rates. The studies were divided into groups with distinct definitions of curative resection for rectal cancer. Meta-analyses were performed to pool the risks of local recurrence by group definition. Statistical tests were used to explore the variation in local recurrence by group. Confounding relationships of age, sex, Dukes stage, length of follow-up and year of study were explored as far as possible given the limitations of the available data. RESULTS: For rectal cancers significant differences were found between the pooled local recurrence risks by group definition (P < 0.01). Meta-regression tests including all the studies indicate that the definition of curative resection is an important predictor of local recurrence. CONCLUSION: It is suggested that a standardized approach towards defining curative resection and local recurrence may have a significant effect on outcomes in colorectal cancer surgery and would enable comparisons to be made between different series.

Journal Article↗
PubMed2001

Daily variations in deaths in Lithuania: the possible contribution of binge drinking.

BACKGROUND: During the early 1990s the countries of the Former Soviet Union experienced a dramatic rise in mortality, especially from cardiovascular diseases. Although still poorly understood there is evidence, particularly from Russia, that this mortality crisis is partly linked to alcohol consumption. In this paper we use data from Lithuania to explore the daily variations of deaths and the probable relationship with binge drinking. METHODS: Computerized death certificates for those aged 20-59 years were analysed according to the day of death, place of death, and cause of death for the years 1988-1997. RESULTS: There is a marked increase in deaths from accidents, violence, and alcohol poisoning at the weekend, suggesting a pattern of binge drinking in Lithuania. There is also a significant increase in ischaemic heart disease (IHD) deaths on Saturdays, Sundays and Mondays. If the analysis is performed separately according to place of death, the day of the week effect is strengthened for cardiovascular deaths outside of hospital; consistent with the idea of a sudden cardiac death. CONCLUSION: The increase in mortality from cardiovascular diseases observed at the weekend in Lithuania is similar to that observed in Moscow and other populations. The relationship with alcohol consumption is supported by the available physiological evidence. We propose that bingeing can be solely responsible for, or acts as a 'catalyst' for, pathophysiological events by increasing blood pressure, cardiac rhythm and coagulability. The increased IHD mortality observed throughout the weekend and on Monday in Lithuania may reflect the influence of alcohol consumption patterns in a population already subject to high psychosocial stress.

Adult↗
PubMed2001

Mortality in England and Wales attributable to current alcohol consumption.

STUDY OBJECTIVE: To estimate the number of deaths attributable to current alcohol consumption levels in England and Wales by age and sex. DESIGN: Epidemiological approach using published relative risks and population data. SETTING: England and Wales. MAIN OUTCOME MEASURES: Numbers of deaths by age and sex and years of life lost for alcohol related conditions. RESULTS: Because of the cardioprotective properties of alcohol, it is estimated that there are approximately 2% fewer deaths annually in England and Wales than would be expected in a non-drinking population. This proportion varies greatly by age and sex and only among men aged over 55 years and women aged over 65 years is there likely to be found a net favourable mortality balance. It is also estimated that there were approximately 75 000 premature years of life lost in England and Wales in 1996 attributable to alcohol consumption. The main causes of alcohol attributable mortality among the young include road traffic fatalities, suicide and alcoholic liver disease. CONCLUSIONS: At a population level, current alcohol consumption in England and Wales may marginally reduce mortality. However, the benefit is disproportionately found among the elderly. Estimating alcohol attributable mortality by age and sex may be a useful indicator for developing alcohol strategies. More research into the possible effect modifications of pattern of consumption, beverage type, age and gender will enable these estimates to be improved.

Accidents↗
PubMed2001

Preferences and understanding their effects on health.

Preference for a particular intervention may, possibly via complicated pathways, itself confer an outcome advantage which will be subsumed in unblind randomised trials as part of the measured effectiveness of the intervention. Where more attractive interventions are compared with less attractive ones, any difference could therefore be a consequence of attractiveness and not its intrinsic worth. For health promotion interventions this is clearly important, but we cannot tell how important it is for therapeutic interventions without special studies to measure or refute such effects. These are difficult to do and are complex. Until the therapeutic effects of preference itself are more clearly understood, understanding the true therapeutic effects will be compromised, at least in principle.

Bias↗
PubMed2000

Multidisciplinary team interventions for delirium in patients with chronic cognitive impairment.

BACKGROUND: Delirium is common in hospitalized elderly people. In the frail elderly, delirium may occur in 60% of those hospitalized. In the cognitively impaired, 45% have been shown to develop delirium and these patients have longer lengths of stay and a higher rate of complications which, amongst other things, together contribute to an increase in cost of care. The combination of being elderly and chronically cognitively impaired leads to a high risk of delirium with the associated increased risk of prolonged hospital stay, complications, and poor outcomes. The management of delirium has commonly been multifaceted - the primary emphasis has always been on the diagnosis and therapy of the precipitating factors, but as this may not be immediately resolved, symptomatic and supportive care may become of major importance. OBJECTIVES: The objective of this review is to assess the available evidence for the effectiveness, if any, of multidisciplinary team interventions in the coordinated care of patients with delirium superimposed on an underlying chronic cognitive impairment compared with the usual care of older cognitively impaired patients. SEARCH STRATEGY: The Cochrane Controlled Trials Register (Cochrane Library, up to and including Issue 1, 1998) was searched using the terms 'delirium, controlled trial, cognitive'. MEDLINE, EMBASE and Psychlit (Ovid via Winspirs up to Feb 1998) were also searched with the same terms. Other sources including personal communications, ongoing trials, conference proceedings, handsearching and reference lists of published papers and books were all searched for relevant randomized controlled trials. The total yield from searching was 157 from which 8 (eight) were retained for consideration in the review. SELECTION CRITERIA: From the initial search yields, all randomised controlled trials involving the management of elderly patients with delirium were identified. A single reviewer (AMB) discarded irrelevant publications based on the title of the publication and its abstract. In the event that the article could possibly be relevant, it was retrieved for further assessment. All references were compiled in a list with a commentary on type of article, eg review, prospective study etc and this was independently considered by the second reviewer (RR) who agreed to review all randomised controlled studies reported on patients with delirium. Selection for possible inclusion in this review was then made on the basis of the participants reported as having chronic cognitive impairment, who then developed incident delirium and were randomly assigned to either coordinated multidisciplinary care or usual care. The outcomes of interest were length of stay in hospital, morbidity (including complications), patient distress & impact on care environment, mortality, discharge arrangements and follow-up including assessment of cognitive function at 6 months. Studies in which patients with chronic cognitive impairment or dementia, managed for incident delirium, according to ICD 9 criteria (see note) were considered eligible for inclusion in the review. Studies of risk factors and non-randomized studies were excluded. Note: this classification has been widely utilised throughout the English speaking medical literature over the past 20 years: ICD 10 is still being incorporated into clinical coding systems and has not been utilised in studies published in 1996. (ABSTRACT TRUNCATED)

Delirium↗
PubMed2000

Public health implications of new guidelines for lead in drinking water: a case study in an area with historically high water lead levels.

Concern about the neurotoxicity of lead, particularly in infants and young children, has led to a revision of blood lead levels which are considered to involve an acceptable level of human exposure. Drinking water guidelines have also been reviewed in order to reduce this source of population exposure to lead. In the last 20 years, guidelines have been reduced from 100 to 50 to 10 microg/litre. Lead in tap water used to be a major public health problem in Glasgow because of the high prevalence of houses with lead service pipes, the low pH of the public water supply and the resulting high levels of lead in water used for public consumption. Following two separate programmes of water treatment, involving the addition of lime and, a decade later, lime supplemented with orthophosphate, it is considered that maximal measures have been taken to reduce lead exposure by chemical treatment of the water supply. Any residual problem of public exposure would require large scale replacement of lead service pipes. In anticipation of the more stringent limits for lead in drinking water, we set out to measure current lead exposure from tap water in the population of Glasgow served by the Loch Katrine water supply, to compare the current situation with 12 years previously and to assess the public health implications of different limits. The study was based on mothers of young children since maternal blood lead concentrations and the domestic water that mothers use to prepare bottle feeds are the principal sources of foetal and infant lead exposure. An estimated 17% of mothers lived in households with tap water lead concentrations of 10 microg/litre (the [WHO,] guideline) or above in 1993 compared with 49% in 1981. Mean maternal blood lead concentrations fell by 69% in 12 years. For a given water lead concentration, maternal blood lead concentrations were 67% lower. The mean maternal blood lead concentration was 3.7 microg/litre in the population at large, compared with 3.3 microg/litre in households with negligible or absent tap water lead. Nevertheless, between 63% and 76% of cases of mothers with blood lead concentrations of 10 microg/dl or above were attributable to tap water lead. The study found that maternal blood lead concentrations were well within limits currently considered safe for human health. About 15% of infants may be exposed via bottle feeds to tap water lead concentrations that exceed the WHO guideline of 10 microg/litre. In the context of the health and social problems which affect the well-being and development of infants and children in Glasgow, however, current levels of lead exposure are considered to present a relatively minor health problem.

Adult↗
PubMed2000

The relation between alcohol and cardiovascular disease in Eastern Europe: explaining the paradox.

BACKGROUND: Recent evidence from Eastern Europe of a positive association between alcohol and cardiovascular disease has challenged the prevailing view that drinking is cardioprotective. Consuming amounts of alcohol comparable to those consumed in France has been linked to detrimental cardiovascular effects. One possibility is that this could be related to the particular consequences of binge drinking, which is common in Russia. METHODS: A systematic review of literature on the relation between cardiovascular disease and heavy drinking and irregular (binge) drinking. RESULTS: Most existing reviews of the relation between alcohol and cardiovascular disease have examined the amount drunk per week or month and have not looked at the pattern of drinking. These have consistently shown that alcohol has a cardioprotective effect, even at high levels of consumption. In contrast, studies that have looked at pattern of drinking, either directly, or indirectly, using indicators such as frequency of hangovers or reports of the consequences of drunkenness, have consistently found an increased risk of cardiovascular death, particularly sudden death. A separate review of the physiological basis for a difference between regular heavy drinking and heavy binge drinking demonstrates that the two types of drinking have quite different effects. CONCLUSION: An association between binge drinking and cardiovascular death meets the standard criteria for causality. It is important that future studies of alcohol related harm examine the pattern of drinking as well as the amount drunk.

Alcohol Drinking↗
PubMed2000

H2-receptor antagonists may increase the risk of cardio-oesophageal adenocarcinoma: a case-control study.

Adenocarcinoma of the lower oesophagus and the gastric cardia has shown a dramatic worldwide increase in incidence over the last 25 years, but the cause is unknown. A large number of drugs have been introduced over this period of time, and it has been suggested that drugs that relax the lower oesophageal sphincter (DRLOS) might be causative, and on the other hand that non-steroidal anti-inflammatory drugs (NSAIDS) may be protective. H2-receptor antagonists (H2RAs) may allow achlorhydric reflux to continue without symptoms, and it is postulated that such asymptomatic reflux is uncontrolled by the usual conservative measures and may lead to increased oesophageal damage. H2RAs were first marketed in 1970 and might be the cause of the observed increase of cardio-oesophageal adenocarcinoma (COA). In a case-control study, the records of 56 subjects who died of COA in the period 1 January 1990 to 31 December 1992 were compared with those of 56 age-/sex-matched controls who died of myocardial infarction. They were 28 females and 84 males, mean age 69.8 years. The NHS records containing the lifetime prescription history of each subject were retrieved from the health authority. Each prescription was recorded, omitting drugs taken in the two years before diagnosis. Analysis was performed using conditional logistic regression. Other variables, including the use of antacids, steroids, smoking and alcohol, were also examined. Subjects dying of COA were more likely to have consumed H2RAs (relative risk (RR) 7.50, 95% CI 1.33-42.09, P < 0.02). On the other hand, they were less likely to have consumed NSAIDs (RR 0.16, 95% CI 0.03-0.93, P < 0.04) or DRLOS (RR 0.14, 95% CI 0.02-1.0, P = 0.05). This study supports a protective effect from NSAIDs against COA, but the similar effect of DRLOS is related to the increased use of cardiac drugs in the control group. H2RAs appear to have a harmful effect, which may be related to the worldwide increase in COA. However, the trend may have been apparent before cimetidine was widely available, and it is possible that the cause is multi-factorial.

Adenocarcinoma↗
PubMed1999

The impact of patient treatment preferences on the interpretation of randomised controlled trials.

Reliable information about aggregate main treatment effects in cancer research comes from randomised controlled trials (RCTs). The possibility of important interactions, such as between treatment preferences and their effects, is necessarily subordinated in the quest for evidence about main treatment effects. If patient preferences can influence the effectiveness of treatments, for which there is some indirect evidence, then those estimates of the treatment's main organic effects from unblind RCTs might be wrong. RCTs clearly disallow patient choice and it is, therefore, important to know the extent of any preference effects in order to interpret the RCT evidence. It may be important to know whether they exist, and where and by how much they affect outcome. It is argued that measuring these effects reliably is methodologically difficult, and will require massive trials each directed at measuring one particular preference effect. Such effects have a slightly fanciful image, particularly in cancer treatment, and may be transient. Given the current uncertainties about their true nature and plausible biological mechanisms, the accumulated evidence is unlikely to provide sufficient justification for investing in such trials, given other current priorities.

Humans↗
PubMed1999

Mortality attributable to drinking, drinking too much, or drinking too little: a comparison of methods.

BACKGROUND: The existence of a U-shaped relationship between alcohol consumption and all-cause mortality complicates the calculation and interpretation of mortality attributable to alcohol consumption. METHODS: We used the relationships between all-cause mortality and alcohol consumption from four British cohort studies. For each study we defined a 'sensible drinking level' asthe level with lowest observed mortality. We estimated the fractions of deaths that were attributable to (1) any drinking (compared with not drinking), (2) drinking more than the 'sensible level', and (3) drinking less than the 'sensible level'. RESULTS: Data from the Doctors' study suggest that on balance 22.3 per cent of deaths are prevented by alcohol consumption, yet the fractions of deaths attributable to drinking more than 8-14 units per week and less than 8-14 units per week are nearly equal (6.5 per cent and 6.4 per cent, respectively). In a sensitivity analysis we show that it is possible for alcohol consumption to prevent deaths overall yet for more deaths to be attributable to drinking above a sensible level than are attributable to drinking below the sensible level. CONCLUSIONS: The balance of deaths attributable to or prevented by alcohol consumption provides no information about the deaths attributable to drinking above or below sensible levels. Using all-cause data in this way is likely to exaggerate the protective effect of alcohol consumption, so our results are only illustrative.

Alcohol Drinking↗
PubMed1999

Threats to applicability of randomised trials: exclusions and selective participation.

BACKGROUND: Although the randomised controlled trial (RCT) is regarded as the 'gold standard' in terms of evaluating the effectiveness of interventions, it is susceptible to challenges to its external validity if those participating are unrepresentative of the reference population for whom the intervention in question is intended. In the past, reporting on numbers and types of potential subjects that have been excluded by design, and centres, clinicians or patients that have elected not to participate, has generally been poor, and the threat to inference posed by possible selection bias is unclear. METHODS: A systematic review was undertaken, based largely on MEDLINE and EMBASE with follow-up of cited references, to assess the extent, nature and importance of excluding potential subjects or the unwillingness of particular centres, clinicians or patients to participate. RESULTS: RCTs vary widely in the extent to which potential future recipients of treatment are included. The reasons cited for excluding certain categories of patient may be medical or scientific. Medical reasons include a high risk of adverse effects and the belief that benefit will be relatively small or absent (or has already been established) in the groups in question. Scientific reasons include more precise estimates of treatment effect because of a relatively homogeneous sample and the reduction of potential bias by excluding those individuals most likely to be lost to follow-up. Many RCTs have blanket exclusions, such as the elderly, women and ethnic minorities, but reasons for these exclusions are seldom given. Evaluative research is undertaken predominantly in university or teaching centres. Non-randomised studies are more likely than RCTs to include non-teaching centres. The effect of patient non-participation appears to depend on whether the RCT is concerned with treatment of an existing condition or with disease prevention. Participants in treatment trials tend to be more severely ill than those who do not participate. In contrast, those who participate in prevention trials are more likely to have adopted a healthy lifestyle than those who decline. Most evaluative studies fail to document adequately the characteristics of those who, while eligible, do not participate. However, subjects included in RCTs (i.e. eligible and participating) tend to have a different prognosis than patients identified from clinical databases. CONCLUSIONS: Narrow inclusion criteria may offer benefits such as increased precision and reduced loss to follow-up, but there are important disadvantages, such as uncertainty about extrapolation of results, which may result in denial of effective treatment to groups who might benefit, and delay in obtaining definitive results because of reduced recruitment rate. Selective participation by teaching centres and sicker patients in treatment RCTs may exaggerate the measured treatment effect. Prevention trials, on the other hand, may underestimate effects as participants have less capacity to benefit.

Australia↗