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339 result(s) for "Doll, Richard"
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Mortality in relation to smoking: 50 years' observations on male British doctors
Abstract Objective To compare the hazards of cigarette smoking in men who formed their habits at different periods, and the extent of the reduction in risk when cigarette smoking is stopped at different ages. Design Prospective study that has continued from 1951 to 2001. Setting United Kingdom. Participants 34 439 male British doctors. Information about their smoking habits was obtained in 1951, and periodically thereafter; cause specific mortality was monitored for 50 years. Main outcome measures Overall mortality by smoking habit, considering separately men born in different periods. Results The excess mortality associated with smoking chiefly involved vascular, neoplastic, and respiratory diseases that can be caused by smoking. Men born in 1900-1930 who smoked only cigarettes and continued smoking died on average about 10 years younger than lifelong non-smokers. Cessation at age 60, 50, 40, or 30 years gained, respectively, about 3, 6, 9, or 10 years of life expectancy. The excess mortality associated with cigarette smoking was less for men born in the 19th century and was greatest for men born in the 1920s. The cigarette smoker versus non-smoker probabilities of dying in middle age (35-69) were 42% ν24% (a twofold death rate ratio) for those born in 1900-1909, but were 43% ν 15% (a threefold death rate ratio) for those born in the 1920s. At older ages, the cigarette smoker versus non-smoker probabilities of surviving from age 70 to 90 were 10% ν 12% at the death rates of the 1950s (that is, among men born around the 1870s) but were 7% ν 33% (again a threefold death rate ratio) at the death rates of the 1990s (that is, among men born around the 1910s). Conclusion A substantial progressive decrease in the mortality rates among non-smokers over the past half century (due to prevention and improved treatment of disease) has been wholly outweighed, among cigarette smokers, by a progressive increase in the smoker ν non-smoker death rate ratio due to earlier and more intensive use of cigarettes. Among the men born around 1920, prolonged cigarette smoking from early adult life tripled age specific mortality rates, but cessation at age 50 halved the hazard, and cessation at age 30 avoided almost all of it.
Cancer Risks Attributable to Low Doses of Ionizing Radiation: Assessing What We Really Know
High doses of ionizing radiation clearly produce deleterious consequences in humans, including, but not exclusively, cancer induction. At very low radiation doses the situation is much less clear, but the risks of low-dose radiation are of societal importance in relation to issues as varied as screening tests for cancer, the future of nuclear power, occupational radiation exposure, frequent-flyer risks, manned space exploration, and radiological terrorism. We review the difficulties involved in quantifying the risks of low-dose radiation and address two specific questions. First, what is the lowest dose of x- or γ-radiation for which good evidence exists of increased cancer risks in humans? The epidemiological data suggest that it is ≈10-50 mSv for an acute exposure and ≈50-100 mSv for a protracted exposure. Second, what is the most appropriate way to extrapolate such cancer risk estimates to still lower doses? Given that it is supported by experimentally grounded, quantifiable, biophysical arguments, a linear extrapolation of cancer risks from intermediate to very low doses currently appears to be the most appropriate methodology. This linearity assumption is not necessarily the most conservative approach, and it is likely that it will result in an underestimate of some radiation-induced cancer risks and an overestimate of others.
The Effect of Group Psychosocial Support on Survival in Metastatic Breast Cancer
In this randomized trial, the addition of a form of group therapy called supportive–expressive group therapy to standard medical care did not prolong the survival of women with metastatic breast cancer. The therapy did, however, alleviate psychological symptoms. In this randomized trial, the addition of group therapy to standard care did not prolong survival. In 1989, Spiegel et al. 1 reported a randomized trial of supportive–expressive group therapy in women with metastatic breast cancer. Supportive–expressive group therapy is a standardized treatment for those with life-threatening illness that encourages participants to express feelings and concerns about their illness and its effect on their lives in the supportive environment of a therapist-led group. The women who participated in such therapy lived a mean of 18 months longer than the women in the control group. 2 , 3 However, since the statistical analysis of survival had not been planned, these results called for further investigation. Two recent randomized trials of . . .
Alcohol Consumption and Mortality among Middle-Aged and Elderly U.S. Adults
Men and women who drink alcoholic beverages regularly have, in comparison with abstainers, higher death rates from injuries, 1 , 2 violence, 2 suicide, 2 poisoning, 3 cirrhosis, 4 certain cancers, 5 and possibly hemorrhagic stroke, 6 , 7 but lower death rates from coronary heart disease and thrombotic stroke. 8 – 27 The net balance of risks and benefits is likely to differ in different age groups and populations. Examining this balance in a particular population requires large epidemiologic studies that have information on all causes of death and include sufficient numbers of people and deaths to estimate risks reliably within subgroups defined according to age, sex, and tobacco use. . . .
The Psychosocial Screen for Cancer (PSSCAN): Further validation and normative data
Background We have previously reported on the development of a cancer-specific screening instrument for anxiety and depression (PSSCAN). No information on cut-off scores or their meaning for diagnosis was available when PSSCAN was first described. Needed were additional analyses to recommend empirically justified cut-off scores as well as data norms for healthy adult samples so as to lend meaning to the recommended cut-off scores. Methods We computed sensitivity/specificity indices based on a sample of 101 cancer patients who had provided PSSCAN data on anxiety and depression and who had completed another standardized instrument with strong psychometrics. Next, we compared mean scores for four samples with known differences in health status, a healthy community sample (n = 561), a sample of patients with a representative mix of cancer subtypes (n = 570), a more severely ill sample of in-patients with cancer (n = 78), and a community sample with a chronic illness other than cancer (n = 85). Results Sensitivity/specificity analyses revealed that an excellent balance of sensitivity/specificity was achievable with 92%/98% respectively for clinical anxiety and 100% and 86% respectively for clinical depression. Newly diagnosed patients with cancer were no more anxious than healthy community controls but showed elevations in depression scores. Both, patients with chronic illness other than cancer and those with longer-standing cancer diagnoses revealed greater levels of distress than newly diagnosed cancer patients or healthy adult controls. Conclusion These additional data on criterion validity and community versus patient norms for PSSCAN serve to enhance its utility for clinical practice.
Mortality of British Radiologists: A Lecture Note
The precautions introduced after the first 23 years experience of the use of x-rays for medical diagnosis proved adequate to eliminate the acute hazards of exposure, but it was much longer before it was realized that small doses that did not produce any acute effect could increase the risk of cancer. British radiologists who took up the specialty at different periods have, therefore, been studied to see if the risk has now been adequately controlled. Four groups have been studied starting respectively before 1921, in 1921-34, 1935-54, and 1955-77, corresponding approximately to periods when different limits of exposure were applied. Altogether 2698 male radiologists have been identified and all but 27 followed successfully to emigration, death, or survival to January 1st 1997. Of the 1198 who had died, 228 are known to have died of cancer. Two problems arise in evaluating the carcinogenic hazard to which they were exposed: the assessment of the doses received and the selection of an appropriate control group with which to compare their mortality. The most appropriate comparison group would seem to be medical practitioners in general. In comparison with them, radiologists entering in the first 3 periods had increased risks of death from cancer though appreciably less than would have been predicted from the expected effect of the radiation they had received. Those who joined in the latest period had a relatively reduced risk, irrespective of any effect of the small dose of radiation they are likely to have received. Independent evidence suggests, however, that since 1951 radiologists have smoked less than other doctors and the lower than predicted risk in the groups exposed since 1920 is limited to smoking related cancers, the mortality from other cancers being higher than in doctors generally. In assessing the risk of occupational exposure to radiation, life-style has to be taken into consideration, as well as dose of radiation.
Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials
Low-dose aspirin is of definite and substantial net benefit for many people who already have occlusive vascular disease. We have assessed the benefits and risks in primary prevention. We undertook meta-analyses of serious vascular events (myocardial infarction, stroke, or vascular death) and major bleeds in six primary prevention trials (95 000 individuals at low average risk, 660 000 person-years, 3554 serious vascular events) and 16 secondary prevention trials (17 000 individuals at high average risk, 43 000 person-years, 3306 serious vascular events) that compared long-term aspirin versus control. We report intention-to-treat analyses of first events during the scheduled treatment period. In the primary prevention trials, aspirin allocation yielded a 12% proportional reduction in serious vascular events (0·51% aspirin vs 0·57% control per year, p=0·0001), due mainly to a reduction of about a fifth in non-fatal myocardial infarction (0·18% vs 0·23% per year, p<0·0001). The net effect on stroke was not significant (0·20% vs 0·21% per year, p=0·4: haemorrhagic stroke 0·04% vs 0·03%, p=0·05; other stroke 0·16% vs 0·18% per year, p=0·08). Vascular mortality did not differ significantly (0·19% vs 0·19% per year, p=0·7). Aspirin allocation increased major gastrointestinal and extracranial bleeds (0·10% vs 0·07% per year, p<0·0001), and the main risk factors for coronary disease were also risk factors for bleeding. In the secondary prevention trials, aspirin allocation yielded a greater absolute reduction in serious vascular events (6·7% vs 8·2% per year, p<0.0001), with a non-significant increase in haemorrhagic stroke but reductions of about a fifth in total stroke (2·08% vs 2·54% per year, p=0·002) and in coronary events (4·3% vs 5·3% per year, p<0·0001). In both primary and secondary prevention trials, the proportional reductions in the aggregate of all serious vascular events seemed similar for men and women. In primary prevention without previous disease, aspirin is of uncertain net value as the reduction in occlusive events needs to be weighed against any increase in major bleeds. Further trials are in progress. UK Medical Research Council, British Heart Foundation, Cancer Research UK, and the European Community Biomed Programme.
Effect of four monthly oral vitamin D3 (cholecalciferol) supplementation on fractures and mortality in men and women living in the community: randomised double blind controlled trial
Abstract Objective: To determine the effect of four monthly vitamin D supplementation on the rate of fractures in men and women aged 65 years and over living in the community. Design: Randomised double blind controlled trial of 100 000 IU oral vitamin D3 (cholecalciferol) supplementation or matching placebo every four months over five years. Setting and participants: 2686 people (2037 men and 649 women) aged 65-85 years living in the general community, recruited from the British doctors register and a general practice register in Suffolk. Main outcome measures: Fracture incidence and total mortality by cause. Results: After five years 268 men and women had incident fractures, of whom 147 had fractures in common osteoporotic sites (hip, wrist or forearm, or vertebrae). Relative risks in the vitamin D group compared with the placebo group were 0.78 (95% confidence interval 0.61 to 0.99, P=0.04) for any first fracture and 0.67 (0.48 to 0.93, P=0.02) for first hip, wrist or forearm, or vertebral fracture. 471 participants died. The relative risk for total mortality in the vitamin D group compared with the placebo group was 0.88 (0.74 to 1.06, P=0.18). Findings were consistent in men and women and in doctors and the general practice population. Conclusion: Four monthly supplementation with 100 000 IU oral vitamin D may prevent fractures without adverse effects in men and women living in the general community. What is already known in this topic Vitamin D and calcium supplements are effective in preventing fractures in elderly women Whether isolated vitamin D supplementation prevents fractures is not clear What this paper adds Four monthly oral supplementation with 100 000 IU vitamin D reduces fractures in men and women aged over 65 living in the general community Total fracture incidence was reduced by 22% and fractures in major osteoporotic sites by 33%
Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies
Abstract Objective and design: To relate UK national trends since 1950 in smoking, in smoking cessation, and in lung cancer to the contrasting results from two large case-control studies centred around 1950 and 1990. Setting: United Kingdom. Participants: Hospital patients under 75 years of age with and without lung cancer in 1950 and 1990, plus, in 1990, a matched sample of the local population: 1465 case-control pairs in the 1950 study, and 982 cases plus 3185 controls in the 1990 study. Main outcome measures: Smoking prevalence and lung cancer. Results: For men in early middle age in the United Kingdom the prevalence of smoking halved between 1950 and 1990 but the death rate from lung cancer at ages 35–54 fell even more rapidly, indicating some reduction in the risk among continuing smokers. In contrast, women and older men who were still current smokers in 1990 were more likely than those in 1950 to have been persistent cigarette smokers throughout adult life and so had higher lung cancer rates than current smokers in 1950. The cumulative risk of death from lung cancer by age 75 (in the absence of other causes of death) rose from 6% at 1950 rates to 16% at 1990 rates in male cigarette smokers, and from 1% to 10% in female cigarette smokers. Among both men and women in 1990, however, the former smokers had only a fraction of the lung cancer rate of continuing smokers, and this fraction fell steeply with time since stopping. By 1990 cessation had almost halved the number of lung cancers that would have been expected if the former smokers had continued. For men who stopped at ages 60, 50, 40, and 30 the cumulative risks of lung cancer by age 75 were 10%, 6%, 3%, and 2%. Conclusions: People who stop smoking, even well into middle age, avoid most of their subsequent risk of lung cancer, and stopping before middle age avoids more than 90% of the risk attributable to tobacco. Mortality in the near future and throughout the first half of the 21st century could be substantially reduced by current smokers giving up the habit. In contrast, the extent to which young people henceforth become persistent smokers will affect mortality rates chiefly in the middle or second half of the 21st century.
Familial breast cancer: collaborative reanalysis of individual data from 52 epidemiological studies including 58 209 women with breast cancer and 101 986 women without the disease
Women with a family history of breast cancer are at increased risk of the disease, but no study has been large enough to characterise reliably how, over women's lives, this risk is influenced by particular familial patterns of breast cancer. This report, on the relevance of breast cancer in first-degree relatives, is based on combined data from 52 epidemiological studies. Individual data on breast cancer in first-degree relatives (mothers, sisters, and daughters) of 58 209 women with breast cancer and of 101 986 controls were collected, checked, and analysed centrally. Risk ratios for breast cancer were calculated by conditional logistic regression, stratified by study, age, menopausal status, number of sisters, parity, and age when the first child was born. Breast-cancer incidence and mortality rates for particular family histories were calculated by applying age-specific risk ratios to breast-cancer rates typical for more-developed countries. Altogether 7496 (12·9%) women with breast cancer and 7438 (7·3%) controls reported that one or more first-degree relatives had a history of breast cancer: 12% of women with breast cancer had one affected relative and 1% had two or more. Risk ratios for breast cancer increased with increasing numbers of affected first-degree relatives: compared with women who had no affected relative, the ratios were 1·80 (99% CI 1·69–1·91), 2·93 (2·36–3·64), and 3·90 (2·03–7·49), respectively, for one, two, and three or more affected first-degree relatives (p<0·0001 each). The risk ratios were greatest at young ages, and for women of a given age, were greater the younger the relative was when diagnosed. The results did not differ substantially between women reporting an affected mother (9104) or sister (6386). Other factors, such as childbearing history, did not significantly alter the risk ratios associated with a family history of breast cancer. For women in more-developed countries with zero, one, or two affected first-degree relatives, the estimated cumulative incidence of breast cancer up to age 50 was 1·7%, 3·7%, and 8·0%, respectively; corresponding estimates for incidence up to age 80 were 7·8%, 13·3%, and 21·1%. Corresponding estimates for death from breast cancer up to age 80 were 2·3%, 4·2%, and 7·6%. The age when the relative was diagnosed had only a moderate effect on these estimates. Eight out of nine women who develop breast cancer do not have an affected mother, sister, or daughter. Although women who have first-degree relatives with a history of breast cancer are at increased risk of the disease, most will never develop breast cancer, and most who do will be aged over 50 when their cancer is diagnosed. In countries where breast cancer is common, the lifetime excess incidence of breast cancer is 5·5% for women with one affected first-degree relative and 13·3% for women with two.