ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We conducted a nested case-control study to estimate and compare the relative risks for hospitalizations for newly diagnosed acute liver injury associated with the use of non-steroidal antiinflammatory drugs (NSAIDs) and other hepatotoxic drugs and their interaction. The source population comprised 228,392 members of the Saskatchewan Health Plan from 1982 to 1986. We used hospital records and the databases of the Department of Health. Thirty-four cases with confirmed liver injury were hospitalized. We randomly selected 500 controls from the source population. Crude risks ranged from 1 case per 100,000 prescriptions in current users of methyldopa, ampicillin, or NSAIDs to 14 cases per 100,000 prescriptions in current users of erythromycin estolate. The age-adjusted odds ratios for current users of NSAIDs was 1.8 [95% confidence interval (CI) = 0.8–3.7] and for other hepatotoxic drugs 5.9 (95% CI = 2.8–12.4). The adjusted relative excess risk due to the interaction between current exposure to both categories of drugs was 3.6, accounting for 31% of the cases of acute liver injury among those with exposure to both types of drugs. We conclude that the risk of hospitalization for acute noninfectious liver injury is different among users of various individual potentially hepatotoxic drugs. Concomitant current exposure to two or more drugs increases this risk above what would merely be expected from the sum of the individual risks. (Epidemiology 1993;4:496–501

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We used a model, originally applied in the context of occupational cohort studies to evaluate confounding from smoking, to estimate lung cancer death rates in the Italian population not attributable to active smoking (background rates). Relevant parameters were the percentages of current and former smokers in the population, as derived from national interview surveys, and rate ratios for lung cancer and smoking. We studied differences over time (1956–1958 to 1987–1989) and place (urban/rural) in the background lung cancer death rates while allowing for changes in the average daily amount of tobacco consumption and in duration of smoking. We applied two functions proposed by Whittemore to obtain rate ratios for smokers: one assumes a linear relation between cumulative number of cigarettes smoked and lung cancer death rates; the other is closer to the multistage carcinogenesis theory. All our calculations indicate that the estimated background rates increased in Italy from the period 1956–1958 to the period 1987–1989; the increase was stronger in males than in females. In 1980–1982, higher background rates were observed in heavily urbanized areas than in rural areas. The results did not change when we considered cohort effects in smoking prevalence and when the key parameters were perturbed in a sensitivity analysis. It appears that factors other than smoking play an important role in causing lung cancer in Italy. (Epidemiology 1993;4:502–510

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We conducted a case-control study in Athens, Greece, bepositively related to coronary heart disease, and total carbo-tween January 1990 and April 1991 to examine the associa-hydrates were negatively related to coronary heart disease, tion between diet and coronary heart disease. The case seriesthe nutrient-specific relative risks for a quintile increase being comprised 329 patients with electrocardiographically con1.19 (95% confidence interval = 0.96–1.48) and 0.81 (95% confidence interval = 0.96–1.48) and 0.81 (95% confidence interval =-0.67–0 97),-respectively.-Major fat components (saturated, monounsaturated, and polyunsaturated fat) did not appear to have differential risk implications for coronary heart disease; however, cooking with margarine was associated with an increased relative risk (1.87; 95% confidence interval = 0.82–4.28). Dietary proteins, cholesterol, and vitamin C were not associated with coronary heart disease. (Epidemiology 1993, 4:511–516)

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We considered a simple formulation of the sufficient causes model, in which a preventive agent exerts its effect by preventing a sufficient cause of the disease from occurring, while-leaving another sufficient cause unaffected. Ina-group unexposed to the preventive agent, a case of the disease is caused by whichever of the two sufficient causes occurs alone or first in the subject. Among exposed subjects, the preventive agent prevents only the cases of disease in which the sufficient cause it blocks would have occurred alone, not the cases in which the other sufficient cause also occurs during the study period. The proportion of subjects who would avoid the disease if exposed to the preventive agent is the risk difference. The risk difference varies over time, even when the rates of occurrence of the sufficient causes are constant It increases to a maximum and then declines, as the subjects who have avoided the disease because of the agent later contract the same disease because of exposure to the other sufficient cause. This maximum and the time at which it occurs are readily computed from the incidence rates of disease among exposed and unexposed subjects. (Epidemiology 1993;4:517–523)

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

IfTdis the relative risk of a disorder in the entire population, and rd, is the relative risk of the disorder in i = I,...m strata, then one may show readily that Td= |GS c1Tdwhere ciis the product of two terms, Tithe risk ratio of being in the ith stratum, and Pi,unexp d1the proportion of those with the disorder and unexposed who are in the ith stratum. This formulation is of primary interest in epidemiology when relative risks are available on one or only some strata of a variable that itself may be affected by exposure (what one may define as a “susceptible” covariate) such as mortality or hospitalization. Although relative risks within strata of such a variable may be of some intrinsic clinical interest, only the risk ratio unstratified on such a variate may be pertinent to a causal effect (unlike the case fornonsusceptiblevariables such as sex, age, etc). In some instances, as for birth defects, one may have data from a few strata or only one (for example, livebirths) of a susceptible covariate (for example, conceptus viability). But one may still be able to draw useful inferences about Td,I the risk ratio in the entire population, because if rd,i|Mg 1/ci(or k/ci), one may conclude that Tdis, at least, greater than 1.0 (or k). Similarly, a study of a disorder limited to hospitalized cases and controls may enable investigators to infer, using the same criterion, a positive association in the entire population despite the presence of hospitalization bias of the type described by Berkson. (Epidemiology 1993;4:524529)

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

In a multicenter case-control study that included 400 cases and 297 controls, we examined the relation of moderate alcohol consumption to risk of endometrial cancer. We estimated average weekly intake of alcohol during adulthood from the reported frequency of intake of beer, wine, and liquor. The relative risk of endometrial cancer was 0.82 (95% confidence interval = 0.6–1.2) among women who drank, compared with lifelong abstainers. The weak protective effect of alcohol was due to a stronger inverse association among young women (<55 years). In young women, the age-adjusted relative risks for three levels of drinking (<1, 1–4, > 4 drinks per week), from lowest to highest, were 0.78, 0.64, and 0.41 compared with nondrinkers. The risk estimates were not materially altered after adjustment for a variety of factors related to alcohol intake and to low risk of the disease (for example, smoking, oral contraceptive use, low body mass index, increased physical activity). The protective effect of alcohol could not be attributed to one particular type of alcohol-containing beverage, but beer appeared to have the most pronounced effect. These results suggest an inverse association between moderate alcohol consumption and endometrial cancer risk among young women, but support for a causal association is qualified and requires confirmation. (Epidemiology 1993;4:530–536)

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We examined the cross-sectional relation of dietary vitamin C intake to serum lipids in 1,825 preadolescent black and white girls. Dietary vitamin C intake exclusive of supplement use, determined by 3-day diet record, appeared unrelated to total-serum ein–eholesterol, low-density lipoprotein-cholesterol, and triglyceride levels. Because other investigators have demonstrated an inverse association between vitamin C and total serum cholesterol in individuals with elevated total serum cholesterol levels, we analyzed the subgroup of 285 girls (142 blacks and 143 whites) with total serum cholesterol levels ?|Mg.200 mg per dl. Multivariate analyses of this subgroup, which adjusted for saturated fat, polyunsaturated fat, monounsaturated fat, cholesterol, fiber, and energy intake and for body mass index, demonstrated negative associations between vitamin C intake and total serum cholesterol. In girls with total serum cholesterol levels 200 mg per dl, each 100 mg per day increase in -dietary vitamin-C-intake (ranges 13 373 and-14–242 mg-per - day for blacks and whites, respectively) was associated with a total serum cholesterol decrease of 4 mg per dl (95% confidence limits = −10.34, 2.77) in blacks and 13 mg per dl (95% confidence limits = −22.99, −2.68) in whites. If the observed association is causal and generalizable, our results suggest that increased vitamin C intake could play an important role in the cholesterol homeostasis of females with elevated total cholesterol levels. (Epidemiology 1993;4:537–542)

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID