140 research outputs found
Feral oilseed rape populations within a scottish landscape :Implications for GM coexistence and environmental risk assessment
Reported frequency of physical activity in a large epidemiological study: relationship to specific activities and repeatability over time
BACKGROUND How overall physical activity relates to specific activities and how reported activity changes over time may influence interpretation of observed associations between physical activity and health. We examine the relationships between various physical activities self-reported at different times in a large cohort study of middle-aged UK women. METHODS At recruitment, Million Women Study participants completed a baseline questionnaire including questions on frequency of strenuous and of any physical activity. About 3 years later 589,896 women also completed a follow-up questionnaire reporting the hours they spent on a range of specific activities. Time spent on each activity was used to estimate the associated excess metabolic equivalent hours (MET-hours) and this value was compared across categories of physical activity reported at recruitment. Additionally, 18,655 women completed the baseline questionnaire twice, at intervals of up to 4 years; repeatability over time was assessed using the weighted kappa coefficient (κweighted) and absolute percentage agreement. RESULTS The average number of hours per week women reported doing specific activities was 14.0 for housework, 4.5 for walking, 3.0 for gardening, 0.2 for cycling, and 1.4 for all strenuous activity. Time spent and the estimated excess MET-hours associated with each activity increased with increasing frequency of any or strenuous physical activity reported at baseline (tests for trend, P < 0.003), although the associations for housework were by far the weakest (Spearman correlations, 0.01 and -0.03 respectively for housework, and 0.11-0.37 for all other activities). Repeatability of responses to physical activity questions on the baseline questionnaire declined significantly over time. For strenuous activity, absolute agreement was 64% (κweighted = 0.71) for questionnaires administered less than 6 months apart, and 52% (κweighted = 0.51) for questionnaires more than 2 years apart. Corresponding values for any physical activity were 57% (κweighted = 0.67) and 47% (κweighted = 0.58). CONCLUSIONS In this cohort, responses to simple questions on the frequency of any physical activity and of strenuous activity asked at baseline were associated with hours spent on specific activities and the associated estimated excess MET-hours expended, reported 3 years later. The weakest associations were with housework. Agreement for identical questions asked on two occasions about the frequency of physical activity decreased over time.This work was supported by public funds from Cancer
Research UK and the UK Medical Research Council
Linear law for the logarithms of the Riemann periods at simple critical zeta zeros
Each simple zero 1/2 + iγn of the Riemann zeta function on the critical line with γn > 0 is a center for the flow s˙ = ξ(s) of the Riemann xi function with an associated period Tn. It is shown that, as γn →∞, log Tn ≥ π/4 γn + O(log γn).
Numerical evaluation leads to the conjecture that this inequality can be replaced by an equality. Assuming the Riemann Hypothesis and a zeta zero separation conjecture γn+1 − γn≥ γn-θ for some exponent θ > 0, we obtain the upper bound log Tn ≤ γn2 + θ Assuming a weakened form of a conjecture of Gonek, giving a bound for the reciprocal of the derivative of zeta at each zero, we obtain the expected upper bound for the periods so, conditionally, log Tn = π/ 4 γn +O(log γn). Indeed, this linear relationship is equivalent to the given weakened conjecture, which implies the zero separation conjecture, provided the exponent is sufficiently large. The frequencies corresponding to the periods relate to natural eigenvalues for the Hilbert–Polya conjecture. They may provide a goal for those seeking a self-adjoint operator related to the Riemann hypothesis
Breast Cancer Risk in Relation to the Interval Between Menopause and Starting Hormone Therapy
Background: Although breast cancer risk is greater in users of estrogen-progestin than estrogen-only formulations of menopausal hormonal therapy, reports on their effects have been somewhat inconsistent. We investigated whether the timing of these therapies affected breast cancer incidence. Methods: A total of 1 129 025 postmenopausal UK women provided prospective information on hormonal therapy use and other factors relevant for breast cancer risk. We used Cox regression to estimate adjusted relative risks (RRs) of breast cancer in hormonal therapy users vs never users and calculated standardized incidence rates. All statistical tests were two-sided. Results: During 4.05 million woman-years of follow-up, 15 759 incident breast cancers occurred, with 7107 in current users of hormonal therapy. Breast cancer incidence was increased in current users of hormonal therapy, returning to that of never users a few years after use had ceased. The relative risks for breast cancer in current users were greater if hormonal therapy was begun before or soon after menopause than after a longer gap (Pheterogeneity <. 001, for both estrogen-only and estrogen-progestin formulations). Among current users of estrogen-only formulations, there was little or no increase in risk if use began 5 years or more after menopause (RR = 1.05, 95% confidence interval [CI] = 0.89 to 1.24), but risk was statistically significantly increased if use began before or less than 5 years after menopause (RR = 1.43, 95% CI = 1.35 to 1.51). A similar pattern was observed among current users of estrogen-progestin formulations (RR = 1.53, 95% CI = 1.38 to 1.70, and RR = 2.04, 95% CI = 1.95 to 2.14, respectively). At 50-59 years of age, annual standardized incidence rates for breast cancer were 0.30% (95% CI = 0.29% to 0.31%) among never users of hormone therapy and 0.43% (95% CI = 0.42% to 0.45%) and 0.61% (95% CI = 0.59% to 0.64%), respectively, among current users of estrogen-only and estrogen-progestin formulations who began use less than 5 years after menopause. Conclusions: There was substantial heterogeneity in breast cancer risk among current users of hormonal therapy. Risks were greater among users of estrogen-progestin than estrogen-only formulations and if hormonal therapy started at around the time of menopause than later
Type and timing of menopausal hormone therapy and breast cancer risk: individual participant meta-analysis of the worldwide epidemiological evidence
B
Background
Published findings on breast cancer risk associated with different types of menopausal hormone therapy (MHT) are inconsistent, with limited information on long-term effects. We bring together the epidemiological evidence, published and unpublished, on these associations, and review the relevant randomised evidence.
Methods
Principal analyses used individual participant data from all eligible prospective studies that had sought information on the type and timing of MHT use; the main analyses are of individuals with complete information on this. Studies were identified by searching many formal and informal sources regularly from Jan 1, 1992, to Jan 1, 2018. Current users were included up to 5 years (mean 1·4 years) after last-reported MHT use. Logistic regression yielded adjusted risk ratios (RRs) comparing particular groups of MHT users versus never users.
Findings
During prospective follow-up, 108 647 postmenopausal women developed breast cancer at mean age 65 years (SD 7); 55 575 (51%) had used MHT. Among women with complete information, mean MHT duration was 10 years (SD 6) in current users and 7 years (SD 6) in past users, and mean age was 50 years (SD 5) at menopause and 50 years (SD 6) at starting MHT. Every MHT type, except vaginal oestrogens, was associated with excess breast cancer risks, which increased steadily with duration of use and were greater for oestrogen-progestagen than oestrogen-only preparations. Among current users, these excess risks were definite even during years 1–4 (oestrogen-progestagen RR 1·60, 95% CI 1·52–1·69; oestrogen-only RR 1·17, 1·10–1·26), and were twice as great during years 5–14 (oestrogen-progestagen RR 2·08, 2·02–2·15; oestrogen-only RR 1·33, 1·28–1·37). The oestrogen-progestagen risks during years 5–14 were greater with daily than with less frequent progestagen use (RR 2·30, 2·21–2·40 vs 1·93, 1·84–2·01; heterogeneity p<0·0001). For a given preparation, the RRs during years 5–14 of current use were much greater for oestrogen-receptor-positive tumours than for oestrogen-receptor-negative tumours, were similar for women starting MHT at ages 40–44, 45–49, 50–54, and 55–59 years, and were attenuated by starting after age 60 years or by adiposity (with little risk from oestrogen-only MHT in women who were obese). After ceasing MHT, some excess risk persisted for more than 10 years; its magnitude depended on the duration of previous use, with little excess following less than 1 year of MHT use.
Interpretation
If these associations are largely causal, then for women of average weight in developed countries, 5 years of MHT, starting at age 50 years, would increase breast cancer incidence at ages 50–69 years by about one in every 50 users of oestrogen plus daily progestagen preparations; one in every 70 users of oestrogen plus intermittent progestagen preparations; and one in every 200 users of oestrogen-only preparations. The corresponding excesses from 10 years of MHT would be about twice as great.Central data collection, checking, analysis, and manuscript preparation was supported by the
core funding of the Cancer Epidemiology Unit by CR-UK (C570/A16491)
and the MRC (MR/K02700X/1)
Integrated palliative care in oncology: a protocol for a realist synthesis
Introduction Emerging evidence suggests improved quality of life, reduced symptom burden and lower health services costs when integrated palliative care and cancer care are implemented. Integrated palliative care aims to achieve care continuity by integrating organisational, administrative and clinical services involved in patient care networks. However, integrated palliative care for cancer is not common practice. This project, therefore, aims to understand how integrated palliative care and cancer care works in different healthcare settings (inpatient/outpatient), and for which groups of people (at what stage of the cancer journey), so we can develop guidance for optimal delivery.
Methods and analysis We will conduct a realist synthesis to develop a programme theory of how integrated palliative care in cancer works, for whom and in what contexts to achieve improved symptom management and quality of life for patients and their families.
This realist synthesis will follow the five stages outlined by Pawson: (1) locating existing theories, (2) searching for evidence, (3) article selection, (4) extracting and organising data and (5) synthesising the evidence and drawing conclusions. We will work closely with our expert stakeholder group, which includes health and social care professionals providing palliative care and oncology; management and policy groups and members of the public and patients. We will adhere to RAMESES quality standards for undertaking a realist synthesis.
Ethics and dissemination Ethics approval for this project is not required.
The realist synthesis will develop a programme theory that provides clarity on the optimal delivery of palliative care for adults with cancer. We will use the programme theory to coproduce guidance and user-friendly outputs, working with stakeholders to inform delivery of best practice. Findings will inform further research in integrated palliative care and cancer. Stakeholder engagement will assist in the dissemination of our findings.
PROSPERO registration number CRD42023389791
Comparison of various characteristics of women who do and do not attend for breast cancer screening
BACKGROUND: Information regarding the characteristics and health of women who do and do not attend for breast cancer screening is limited and representative data are difficult to obtain. METHODS: Information on age, deprivation and prescriptions for various medications was obtained for all women at two UK general practices who were invited to breast cancer screening through the National Health Service Breast Screening Programme. The characteristics of women who attended and did not attend screening were compared. RESULTS: Of the 1064 women invited to screening from the two practices, 882 (83%) attended screening. Screening attenders were of a similar age to non-attenders but came from significantly less deprived areas (30% of attenders versus 50% of non-attenders came from the most deprived areas, P < 0.0001) and were more likely to have a current prescription for hormone replacement therapy (32% versus 19%, P < 0.0001). No significant differences in recent prescriptions of medication for hypertension, heart disease, hypercholesterolaemia, diabetes mellitus, asthma, thyroid disease or depression/anxiety were observed between attenders and non-attenders. CONCLUSION: Women who attend the National Health Service Breast Screening Programme come from less deprived areas and are more likely to have a current prescription for hormone replacement therapy than non-attenders, but do not differ in terms of age or recent prescriptions for various other medications
Многоволновая диагностика нанодисперсных частиц, образующихся при плазмохимических процессах, протекающих в магнитном поле
Relationship between body mass index and length of hospital stay for gallbladder disease.
Background: Obesity increases the risk of hospital admission for gallbladder disease but its impact on the length of hospital stay is largely unknown. Methods: Prospective population-based study of 1.3 million women aged 56 years on average, recruited from 1996 to 2001 in England and Scotland and followed-up through NHS hospital admission record databases for gallbladder disease (cholelithiasis, cholecystitis, cholecystectomy) over a total of 7.8 million person-years. Results: During follow-up, 24 953 women were admitted with gallbladder disease, 87% who had a cholecystectomy. After adjusting for age, socioeconomic status and other factors, women with higher BMI at recruitment to the study were more likely to be admitted and spend more days in hospital. For 1000 person-years of follow-up, women in BMI categories of 18.5-24.9, 25-29.9, 30-39.9, 40+ kg/m2 spent, respectively, 16.5[16.0-17.0], 28.6[28.3-28.8], 44.0[43.4-44.5] and 49.4[45.7-53.0] days in hospital for gallbladder disease. Conclusion: On the basis of these estimates, over a quarter of all the days in hospital for gallbladder disease in middle-aged women can be attributed to obesity
Cancer risk among 21st century blood transfusion recipients
Background:
Some carcinogenic viruses are known to be transmissible by blood transfusion. Intensive viral screening of transfused blood now exists in most countries. In the UK, high-sensitivity nucleic acid amplification tests for hepatitis C virus were introduced in 1999 and it was thought that this would reduce, and possibly eliminate, transfusion-related liver cancer. We aimed to investigate cancer risk in recipients of blood transfusion in 2000 or after.
Methods:
A total of 1.3 million UK women recruited in 1998 on average were followed for hospital records of blood transfusion and for cancer registrations. After excluding women with cancer or precancerous conditions before or at the time of transfusion, Cox regression yielded adjusted relative risks of 11 site-specific cancers for women with compared to without prior blood transfusion.
Results:
During follow up, 11 274 (0.9%) women had a first recorded transfusion in 2000 or after, and 1648 (14.6%) of them were subsequently diagnosed with cancer, a mean 6.8 years after the transfusion. In the first 5 years after transfusion there were significant excesses for most site-specific cancers examined, presumably because some had preclinical cancer. However, 5 or more years (mean 8 years) after blood transfusion, there were significant excess risks only for liver cancer (adjusted relative risk = 2.63, 95%CI 1.45-4.78) and for non-Hodgkin lymphoma (adjusted relative risk = 1.74, 1.21-2.51). When analyses were restricted to those undergoing hip or knee replacement surgery, the commonest procedure associated with transfusion, these relative risks were not materially altered.
Conclusions:
In a large cohort of UK women, transfusions in the 21st century were associated with long-term increased risks of liver cancer and non-Hodgkin lymphoma. Some of these malignancies may have been caused by carcinogenic agents that are not currently screened for in transfused blood.The Million Women Study is funded by Medical Research
Council and Cancer Research UK (Cancer Research UK: C570/
A16491, Medical Research Council: MR/K02700X/1
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