Biomedical subjects

Paul Elliott

Publications and source records attributed to Paul Elliott.

At least 37 records · Page 2Linked to original sources

PubMed2004

Paediatric cardiac surgical mortality in England after Bristol: descriptive analysis of hospital episode statistics 1991-2002.

OBJECTIVE: To describe trends in mortality of open cardiac surgery in children in Bristol and England since 1991. DESIGN: Retrospective analysis of hospital episode statistics data. SETTING: All open cardiac surgery of children in England. POPULATION: Patients younger than 16 undergoing open cardiac surgical procedures in England between April 1991 and March 2002. Three time periods were defined: epoch 3 (April 1991 to March 1995), epoch 5 (April 1996 to March 1999), epoch 6 (April 1999 to March 2002). MAIN OUTCOME MEASURE: Mortality in hospital within 30 days of a cardiac procedure. RESULTS: We identified 5221 open operations between April 1996 and March 2002 in children under 1 year and 6385 in children aged 1-15 years. Mortality for all centres combined fell from 12% in epoch 3 to 4% in epoch 6. Mortality in children under 1 year at Bristol fell from 29% (95% confidence interval 21% to 37%) in epoch 3 to 3% (1% to 6%) in epoch 6, below the national average. The reduction in mortality did not seem to be due to fewer high risk procedures or an increase in the numbers of low risk cases. Oxford had a significantly higher mortality than the national average in all three epochs (11% (5% to 18%) in epoch 6), which was not affected by adjusting for procedure or the inclusion of cases with missing outcomes. CONCLUSIONS: At Bristol, mortality for open operations in children aged under 1 year has fallen markedly, to below the national average. Nationwide mortality has also fallen. Improved quality of care may account for the drop in mortality, through new technologies or improved perioperative and postoperative care, or both.

Adolescent↗

PubMed2004

Estimating laboratory precision of urinary albumin excretion and other urinary measures in the International Study on Macronutrients and Blood Pressure.

Microalbuminuria is a risk factor for renal failure, stroke, and cardiovascular disease. However, estimating laboratory precision for albumin excretion is problematic because of its highly skewed distribution and the presence of values below assay detection limits. The authors used 781 quality control pairs from 24-hour urine samples collected between 1996 and 1999 in the International Study on Macronutrients and Blood Pressure (INTERMAP) to compare percentage of technical error (%TE), the usual estimate of laboratory precision, with the mean and median values of within-pair coefficients of variation (CVs) for urinary albumin concentration and other urinary variables. In INTERMAP, %TE was larger than mean CV for all variables. Exclusion of potentially mislabeled samples reduced this difference; for example, for sodium, estimates of %TE and mean and median CV were 2.37%, 0.75%, and 0.28%, respectively, for all 781 pairs and 0.84%, 0.48%, and 0.27%, respectively, with possibly mislabeled pairs excluded. For urinary albumin concentration, exclusion of one mislabeled pair changed estimates for %TE and mean CV from 29.6% and 20.8% to 20.6% and 20.6%, while median CV was unchanged at 9.4%. After exclusion of urinary albumin concentration pairs with values below the detection limit, estimates were 15.4%, 11.4%, and 6.4%, respectively. Results indicate that mean and median CV are not equivalent to %TE and that values below the detection limit can markedly affect estimates and should be excluded.

Adult↗

PubMed2004

Blood pressure differences between northern and southern Chinese: role of dietary factors: the International Study on Macronutrients and Blood Pressure.

Blood pressure and prevalence of high blood pressure are greater for northern than southern Chinese. Reasons for these differences are unclear. Relationships of north-south blood pressure differences with multiple dietary factors were investigated in 839 Chinese participants, International Study on Macronutrients and Blood Pressure (INTERMAP), 561 northern, 278 southern, aged 40 to 59 years. Daily nutrient intakes were determined from four 24-hour dietary recalls and 2 timed 24-hour urine collections. Average systolic/diastolic pressure levels were 7.4/6.9 mm Hg higher for northern than southern participants. Southern participants had lower body mass index, sodium intake, sodium/potassium ratio, and higher intake of calcium, magnesium, phosphorus, and vitamins A and C. Considered singly, with control for age and gender, several dietary variables (eg, body mass index, urinary sodium/potassium ratio, urinary sodium, dietary phosphorus, and magnesium) reduced north-south blood pressure differences by > or =10%. Controlled for age and gender, nondietary variables had little effect on north-south blood pressure differences. With inclusion in regression models of multiple dietary variables (sodium, potassium, magnesium or phosphorus, body mass index), north-south blood pressure differences became much smaller (systolic -1.1, diastolic 1.6 mm Hg) and statistically nonsignificant. In conclusion, multiple dietary factors accounted importantly for north-south blood pressure differences. Efforts are needed to improve nutrition in China, especially in the north, as well as in other populations including those in the United States, for prevention and control of adverse blood pressure levels and major adult cardiovascular disease.

Adult↗

PubMed2004

Manifestations of metabolic syndrome after hypertensive pregnancy.

Small follow-up studies of hospital-based series indicate women with preeclampsia have an increased risk of insulin resistance postpartum. However, long-term data are lacking among women with gestational hypertension without proteinuria. Using a general population-based sample of 5889 women from Northern Finland followed longitudinally since birth in 1966, we examined these associations and the influence of the subject's own birth weight and gestational age on this relationship. At age 31, blood pressure was measured and blood samples collected from 2678 women, of which 1463 women had had at least 1 singleton pregnancy. Of these, 45 had been hospitalized because of gestational hypertension and 49 because of preeclampsia. Women who had had either gestational hypertension or preeclampsia during their first pregnancy (average age 25 years) had increased blood pressure at 31 years compared with women with previous normotensive pregnancy, even after adjustment for body mass index (P<0.001 in gestational hypertension, P=0.023 in preeclampsia group). When compared with the whole female population, women with previous gestational hypertension at same age still had higher blood pressure, while this difference was weaker for women with previous preeclampsia. Women with gestational hypertension and preeclampsia also had higher waist circumference, waist/hip ratio, and body mass index, as well as increased serum insulin levels and lower glucose/insulin ratio than women with previous normotensive pregnancy. The associations remained after adjustment for participant's own birth weight or gestational age. Women born before gestational week 37 had a 2-fold risk for gestational hypertension in their first pregnancy (RR: 2.53; 95% CI: 1.0, 6.2).

Adult↗

PubMed2004

Ethyl glucoside in human urine following dietary exposure: detection by 1H NMR spectroscopy as a result of metabonomic screening of humans.

Metabonomic screening of human urine samples using 1H NMR spectroscopy has revealed the presence of signals resulting from the excretion of ethyl glucoside. Experiments in volunteers have demonstrated that this ethyl glucoside results from dietary exposure to the compound, which is present in beverages such as rice wine and sake, rather than representing a new route for the metabolism of ethanol by humans. The limited studies undertaken in volunteers indicate that ethyl glucoside has a longer biological half life than ethanol itself. The potential problems associated with using this glucoside metabolite as a marker of ethanol consumption are considered.

Chromatography, High Pressure Liquid↗

PubMed2004

Resting heart rate and cause-specific death in a 16.5-year cohort study of the Japanese general population.

BACKGROUND: Several prospective studies have reported resting heart rate (HR) to be a risk factor for certain cause-specific death, together with sex- or age-specific differences in the effects of HR on death. However, there have been few prospective data from non-Western populations. METHODS: Cohort study, over 16.5 years to date of death or end of follow-up (November 15, 1998) involving 8800 men and women > or =30 years of age randomly selected throughout Japan, who participated in the National Survey on Circulatory Disorders in 1980. Resting HR was determined from 3 consecutive intervals between R waves on the 12-lead electrocardiogram. RESULTS: For middle-aged men (30 to 59 years of age), in the highest quartile of HR, there was a significant positive association with cardiovascular (RR, 2.55; 95% CI, 1.22 to 5.31) and all-cause death (RR, 1.45; 95% CI, 1.06 to 2.00). For middle-aged women, in the highest quartile, there was a significant positive association with noncancer, noncardiovascular (RR, 2.41; 95% CI, 1.04 to 5.59), and all-cause death (RR, 1.94; 95% CI, 1.26 to 3.01). Resting HR also showed a significant positive association with cardiac events but not to stroke. These relations were not evident for elderly subjects (> or =60 years of age). Results were not affected when deaths within the first 5 years of follow-up were excluded, except for noncancer, noncardiovascular death. CONCLUSIONS: High resting HR is an independent predictor of long-term death in the Japanese general population.

Adult↗

PubMed2004

A combination of serum low albumin and above-average cholesterol level was associated with excess mortality.

BACKGROUND: There is no population-based prospective study concerning the relation between serum albumin and mortality in a non-Western population, and few previous studies included the subgroup analysis stratified by serum cholesterol level. METHODS: A 13.7-year cohort study was conducted on 6,957 males and females aged 30-59 years from 300 randomly selected areas throughout Japan, who participated in the National Survey on Circulatory Disorders in 1980. RESULTS: In the group with median and above of total cholesterol, one standard deviation (SD) increment of serum albumin (2.6 g/L for males and 2.4 g/L for females) was inversely associated with all-cause mortality for both males and females (relative risk RR = 0.68 and 0.81: 95% confidence interval CI = 0.53-0.87 and 0.68-0.98), and with cancer mortality for females (RR = 0.74; 95% Cl = 0.57-0.96);and the lowest category of serum albumin (< or = 43 g/L) showed the highest cardiovascular mortality for males (RR = 5.04; 95% CI = 1.04-24.5) among the three albumin categories. These relationships were not evident in the group with total cholesterol level below median. CONCLUSION: A combination of a low albumin level and above average cholesterol level, even both within the clinical normal range,is associated with excess mortality in the Japanese general population.

Adult↗

PubMed2004

Standardised coding of diet records: experiences from INTERMAP UK.

Coding diet records is a basic element of most dietary surveys, yet it often receives little attention even though errors in coding can lead to flawed study results. In the INTERnational study of MAcro- and micronutrients and blood Pressure (INTERMAP study), efforts were made to minimise errors in coding the 18, 720 diet records. Staff were centrally trained and certified before being able to process study data and ongoing quality control checks were performed. This involved the senior (site) nutritionist re-coding randomly selected diet records. To facilitate standardisation of coding in the UK, a code book was designed; it included information about coding brand items, density and portion size information, and default codes to be assigned when limited information was available for food items. It was found that trainees, despite previous experience in coding elsewhere, made coding errors that resulted in errors in estimates of daily energy and nutrient intakes. As training proceeded, the number of errors decreased. Compilation of the code book was labour-intensive, as information from food manufacturers and retailers had to be collected. Strategies are required to avoid repetition of this effort by other research groups. While the methods used in INTERMAP to reduce coding errors were time consuming, the experiences suggest that such errors are important and that they can be reduced.

Diet↗

PubMed2004

Tracing ingestion of 'novel' foods in UK diets for possible health surveillance--a feasibility study.

OBJECTIVE: To investigate the feasibility of using commercially available data on household food consumption to carry out food and nutritional surveillance. DESIGN: Taylor Nelson Sofres (TNS) collects information on foods brought home for consumption among a representative quota sample of the British population. In total, 33,177 households and 105,667 individuals provided data between 1991 and 2000. These were used to investigate sociodemographic, geographical and temporal trends in purchase patterns of the main macronutrients and four groups of marker products. RESULTS: Sociodemographic characteristics of the TNS sample were broadly consistent with those of the British population. Estimated energy intakes were slightly low (1667+/-715 kcal) in comparison with other national data. However, percentage energy contributions were consistent with national trends: e.g. consumption of alcohol in the home increased between 1991 and 2000 with higher intakes among more affluent households, while fat intakes decreased slightly over the same period. Significant temporal, geographic and socio-economic trends were found for all nutrients (P<0.0001). Intakes of marker products were sparse (purchased by <4% of households), but significant variations were detected in the proportion of households purchasing some or all of the marker products across temporal, geographic and socio-economic strata. CONCLUSIONS: A prospective nutrient surveillance system could be used to trace consumption patterns of foods or nutrients to inform nutritional surveillance. However, existing data sources would require a number of modifications to increase their suitability for such a project. Increasing surveillance to consider ingredients would require the development of a central coding system, with electronically linked barcode, ingredient and nutrient information.

Adolescent↗

PubMed2004

Does gestation vary by ethnic group? A London-based study of over 122,000 pregnancies with spontaneous onset of labour.

BACKGROUND: Evidence exists that normal gestational length varies with ethnicity. This UK-based study compares gestational length amongst a cohort of white European, Black and Asian women. METHODS: The cohort comprised 122 415 nulliparous women with singleton live fetuses at the time of spontaneous labour, giving birth in the former North West Thames Health Region, London, UK. RESULTS: The median gestational age at delivery was 39 weeks in Blacks and Asians and 40 weeks in white Europeans. Black women with normal body mass index (BMI) (18.5-24.9 kg/m(2)) had increased odds of preterm delivery (odds ratio [OR] = 1.33, 95% CI: 1.15, 1.56, adjusted for deprivation and BMI) compared with white Europeans. The OR of preterm delivery was also increased in Asians compared with white Europeans (OR = 1.45, 95% CI: 1.33, 1.56, adjusted for single unsupported status and smoking). Meconium stained amniotic fluid, which is a sign of fetal maturity, was statistically significantly more frequent in preterm Black and Asian infants and term Black infants compared with white European infants. CONCLUSIONS: This research suggests that normal gestational length is shorter in Black and Asian women compared with white European women and that fetal maturation may occur earlier.

Adolescent↗

PubMed2004

Spatial epidemiology: current approaches and future challenges.

Spatial epidemiology is the description and analysis of geographic variations in disease with respect to demographic, environmental, behavioral, socioeconomic, genetic, and infectious risk factors. We focus on small-area analyses, encompassing disease mapping, geographic correlation studies, disease clusters, and clustering. Advances in geographic information systems, statistical methodology, and availability of high-resolution, geographically referenced health and environmental quality data have created unprecedented new opportunities to investigate environmental and other factors in explaining local geographic variations in disease. They also present new challenges. Problems include the large random component that may predominate disease rates across small areas. Though this can be dealt with appropriately using Bayesian statistics to provide smooth estimates of disease risks, sensitivity to detect areas at high risk is limited when expected numbers of cases are small. Potential biases and confounding, particularly due to socioeconomic factors, and a detailed understanding of data quality are important. Data errors can result in large apparent disease excess in a locality. Disease cluster reports often arise nonsystematically because of media, physician, or public concern. One ready means of investigating such concerns is the replication of analyses in different areas based on routine data, as is done in the United Kingdom through the Small Area Health Statistics Unit (and increasingly in other European countries, e.g., through the European Health and Environment Information System collaboration). In the future, developments in exposure modeling and mapping, enhanced study designs, and new methods of surveillance of large health databases promise to improve our ability to understand the complex relationships of environment to health.

Bayes Theorem↗

PubMed2004

Interpreting posterior relative risk estimates in disease-mapping studies.

There is currently much interest in conducting spatial analyses of health outcomes at the small-area scale. This requires sophisticated statistical techniques, usually involving Bayesian models, to smooth the underlying risk estimates because the data are typically sparse. However, questions have been raised about the performance of these models for recovering the "true" risk surface, about the influence of the prior structure specified, and about the amount of smoothing of the risks that is actually performed. We describe a comprehensive simulation study designed to address these questions. Our results show that Bayesian disease-mapping models are essentially conservative, with high specificity even in situations with very sparse data but low sensitivity if the raised-risk areas have only a moderate (less than 2-fold) excess or are not based on substantial expected counts (> 50 per area). Semiparametric spatial mixture models typically produce less smoothing than their conditional autoregressive counterpart when there is sufficient information in the data (moderate-size expected count and/or high true excess risk). Sensitivity may be improved by exploiting the whole posterior distribution to try to detect true raised-risk areas rather than just reporting and mapping the mean posterior relative risk. For the widely used conditional autoregressive model, we show that a decision rule based on computing the probability that the relative risk is above 1 with a cutoff between 70 and 80% gives a specific rule with reasonable sensitivity for a range of scenarios having moderate expected counts (approximately 20) and excess risks (approximately 1.5- to 2-fold). Larger (3-fold) excess risks are detected almost certainly using this rule, even when based on small expected counts, although the mean of the posterior distribution is typically smoothed to about half the true value.

Bayes Theorem↗

PubMed2004

Variation at the insulin gene VNTR (variable number tandem repeat) polymorphism and early growth: studies in a large Finnish birth cohort.

Variation at the insulin gene (INS-)VNTR (variable number of tandem repeats) minisatellite polymorphism has been reported to be associated with both early growth and adult metabolic phenotypes. However, the samples studied have been small and the relationship between INS-VNTR variation and parameters of early growth inconsistent, with four previous studies producing conflicting results. We have studied the relationship between INS-VNTR class (measured by genotyping the nearby -23HphI variant with which it is in tight linkage disequilibrium) and early growth in 5,646 members of the Northern Finnish Birth Cohort of 1966. Comparing class III homozygotes with other genotypes using multivariate linear regression analysis, we found no significant associations with any early growth measure (birth weight, birth length, ponderal index, and head circumference at 1 year), even after stratifying subjects by growth trajectory during infancy and/or birth order. For example, among infants with limited postnatal growth realignment (n = 2,470), class III/III infants were no heavier at birth (difference [+/-SE] in the means [fully adjusted], 58 +/- 51 g; P = 0.26) than class I/- infants. No significant associations were detected following reanalysis with an additive model (for example, for birth weight, beta = 20 g [95% CI -3 to 44], P = 0.09). Studies of this large population-based cohort have failed to generate convincing evidence that INS-VNTR variation influences early growth.

Birth Order↗

PubMed2003

Stroke mortality associated with living near main roads in England and wales: a geographical study.

BACKGROUND AND PURPOSE: Air pollution is associated with stroke, and road traffic is a major source of outdoor air pollution. Using proximity to roads as a proxy for exposure to road traffic pollution, we examined the hypothesis that living near main roads increases the risk of stroke mortality. METHODS: We used a small-area ecological study design based on 113 465 census enumeration districts in England and Wales. Stroke mortality (International Classification of Disease, 9th revision, codes 430 through 438) in England and Wales from 1990 to 1992 for people >or=45 years of age was examined through the use of 1991 population denominators. Exposure was calculated as distance from each enumeration district population centroid to the nearest main road. We adjusted for age, sex, socioeconomic deprivation (using Carstairs index), regional variation, urbanization, and metropolitan area using Poisson regression. RESULTS: The analysis was based on 189 966 stroke deaths and a population of 19 083 979. After adjustment for potential confounders, stroke mortality was 7% (95% confidence interval [CI], 4 to 9) higher in men living within 200 m of a main road compared with men living >or=1000 m away. The corresponding increase in risk for women was 4% (95% CI, 2 to 6) and the risk for men and women combined was 5% (95% CI, 4 to 7). These raised risks diminished with increasing distance from main roads. CONCLUSIONS: Living near main roads is associated with excess risk of mortality from stroke, and if causality were assumed, approximately 990 stroke deaths per year would have been attributable to road traffic pollution.

Age Distribution↗

PubMed2003

The Initial Health Assessment: an intervention to identify the supportive care needs of cancer patients.

BACKGROUND: The first step in effective supportive care delivery is an assessment of patient needs. The Initial Health Assessment Form (IHA) was developed to aid clinicians in recognition and documentation of a patient's supportive care needs during their first visit to a comprehensive cancer centre. The purpose of this study was to determine the relative effectiveness of this instrument as compared to routine practice. METHODS: A before-after study was performed. Charts of consecutive patients with newly diagnosed cancer attending the Hamilton Regional Cancer Centre were selected randomly. Each chart was reviewed to determine the documentation at the initial patient assessment of 22 supportive care items under eight domains of need: physical, psychological, daily living, social, financial, informational, special needs and personal resources. The pre-intervention evaluation (T1) occurred over a 3-month period followed by the introduction of the IHA into clinical practice. Three months after its introduction, the post-intervention (T2) evaluation took place over the ensuing 3 months. RESULTS: A total of 306 charts were evaluated (153 each in T1 and T2). Patients from the two time periods were comparable with respect to background demographic variables. Introduction of the IHA increased the mean documentation of supportive care needs and resources from 26% in T1 to 49% in T2 ( p=0.001). Significant improvements were found in all domains of need. Despite improvements, documentation of assessment continued to remain low for daily living, social, financial, and informational needs. CONCLUSIONS: The IHA improved documentation of supportive care needs and resources. There is still room for improvement.

Adult↗

PubMed2003

Trends in drug overdose deaths in England and Wales 1993-98: methadone does not kill more people than heroin.

AIMS: To test the hypothesis that methadone is responsible for a greater increase in overdose deaths than heroin, and causes proportionally more overdose deaths than heroin at weekends. DESIGN AND SETTING: Multivariate analysis of 3961 death certificates mentioning heroin, morphine and/or methadone held on the Office for National Statistics drug-related poisoning mortality database from 1993 to 1998 in England and Wales. MEASUREMENTS: Percentage increase in deaths by year by drug, odds ratio (OR) of dying at the weekend from methadone-related overdose compared to dying from heroin/morphine overdose. FINDINGS: From 1993 to 1998, annual opiate overdose deaths increased from 378 to 909. There was a 24.7% (95% confidence interval (CI) 22-28%) yearly increase in heroin deaths compared to 9.4% (95% CI 6-13%) for methadone only. This difference was significant (P < 0.001 by test of interaction) after adjustment for sex, age group, polydrug use, area of residence and underlying cause of death. The largest number of deaths occurred on Saturday (673). The OR of death from methadone overdose on Saturday and Sunday was 1.48 (95% CI 1.29-1.71) for methadone-only deaths compared to dying from heroin/morphine at the weekend after adjustment for other covariates, but the OR was not significant (1.09, 95% CI 0.95-1.25) if the weekend was defined as Friday and Saturday. CONCLUSIONS: There was no evidence that the threefold increase in deaths over time was due to methadone. There was equivocal support only for the hypothesis that there was an excess of deaths from methadone at weekends. Increased interventions to prevent overdose among injectors in England and Wales are long overdue.

Adolescent↗

PubMed2003

Protein intake and blood pressure in cardiovascular disease.

Raised blood pressure (BP) is a major cause of CHD and the leading cause of stroke. Although BP rises with age in most populations, there are remote populations around the world where BP does not rise with age and where the high prevalence of high BP and frank hypertension seen in the UK and other Western countries in the older age-groups is not found. However, when such populations migrate to urban settings, their BPs rise, indicating that the population-wide BP problem is largely environmental in origin. Thus, a substantial body of evidence has accumulated on the importance of dietary factors in BP (Na and alcohol intakes (direct relationship) and K intake (inverse relationship)) as well as body weight (direct relationship). More recently, attention has shifted to other dietary factors that might affect BP. Data from studies of vegetarians (who tend to have lower BP than meat-eating populations) as well as clinical data on the adverse effects of protein intake in patients with renal insufficiency led to the view in Western countries that dietary (animal or total) protein had an adverse effect on BP. By contrast, studies in Japan and China suggested that dietary protein might be protective of high BP and stroke. Recent epidemiological studies have found inverse associations between dietary protein intake and BP, consistent with this view, and supported by some evidence from animal studies. Recent controlled clinical trials of soyabean supplementation have also suggested a BP-lowering effect of protein intake. Results of further large-scale epidemiological studies of protein and BP are awaited.

Aging↗

PubMed2003

Erasmus Darwin, Herbert Spencer, and the origins of the evolutionary worldview in British provincial scientific culture, 1770-1850.

The significance of Herbert Spencer's evolutionary philosophy has been generally recognized for over a century, as the familiarity of his phrase "survival of the fittest" indicates, yet accounts of the origins of his system still tend to follow too closely his own description, written many decades later. This essay argues that Spencer's own interpretation of his intellectual development gives an inadequate impression of the debt he owed to provincial scientific culture and its institutions. Most important, it shows that his evolutionism was originally stimulated by his association with the Derby philosophical community, for it was through this group--of which his father, who also appears to have espoused a deistic evolutionary theory, was a member--that he was first exposed to progressive Englightenment social and educational philosophies and to the evolutionary worldview of Erasmus Darwin, the first president of the Derby Philosophical Society. Darwin's scheme was the first to incorporate biological evolution, associationist psychology, evolutionary geology, and cosmological developmentalism. Spencer's own implicit denials of the link with Darwin are shown to be implausible in the face of Darwin's continuing influence on the Derby savants, the product of insecurity in his later years when he feared for his reputation as Lamarckism became increasingly untenable.

Biological Evolution↗