ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The assessment of leisure-time physical activity in four studies that used a similar questionnaire was carried out by the University of Minnesota between 1957–1960 and 1985–1987. Each study included adults living in the Upper Midwest. In men, age-adjusted leisure-time energy expenditure consistently increased over time, with the greatest increase occurring between 1957–1960 and 1974–1975. Much of this increase occurred in moderate and heavy intensity activity and was greater for white collar workers than for blue collar workers. The increase in the last period was similar for both classes of workers. Data were unavailable for women before 1980. Age-adjusted leisure-time physical activity in women also increased between 1980–1982 and 1985–1987. This increase was greater for blue collar than for white collar women. A major strength of these analyses is the last two surveys, which were specifically designed to assess time trends. Exact comparability of the earlier two surveys with the two latter surveys cannot be established; however, the use of the same detailed questionnaire across 30 years is unique. We conclude that leisure-time physical activity has been increasing for three decades, including substantial increases in vigorous activities

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

As part of a prospective study begun in 1981, we evaluated 8,600 postmenopausal women and 5,049 men residing in a southern California retirement community for risk factors for hip fracture. Incidence rates were twice as high in women as in men, but in both sexes the rates nearly doubled every 5 years between 70 and 90 years. Active exercise was strongly and negatively associated with hip fracture risk in both sexes; the age-adjusted relative risk was 0.6 and 0.5 for females and males, respectively, for 1 or more hours of exercise per day compared with less than 1/2 hour of exercise. A high body mass index (upper tertile of weight divided by height squared) was associated with a strong reduction in hip fracture risk for females (RR = 0.5). Current cigarette smokers had a significantly increased risk (RR = 1.8 and RR = 2.2 for females and males, respectively) compared with never-smokers, but the risk for past smokers was not different from that of lifetime nonsmokers. Other factors related to reduced hip fracture risk in women were high parity, late age at menarche, and long menstrual cycle length. These age-adjusted relative risk estimates did not change materially in multivariate analysis when adjusted simultaneously for age, active exercise, body mass, smoking, and, for women, age at menarche and number of children. Among estrogen users, the lowest risk of hip fracture was observed for recent users (RR = 0.8), while users who had stopped estrogen use 15 or more years ago had a relative risk of 1.1, suggesting that the protective effect of estrogen dissipates after many years since cessation of estrogen therapy

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We investigated the prevalence and correlates of angina pectoris in 6573 men and women aged 20–59 participating in the Italian National Multicenter Study on Risk Factors for Arteriosclerosis. In both sexes, the prevalence of angina pectoris, as assessed by the Rose questionnaire, increased sharply with age (from 0.8% to 5.1% for men and from 1.7% to 6.9% for women). In all age groups, there was a higher prevalence of angina pectoris for women than for men. In men, a strong positive association was found between angina pectoris and myocardial infarction (both by self-report and electrocardiographic documentation) and self-reported dyspnea. In women, myocardial infarction (self-reported), electrocardiographic-documented myocardial ischemia, intermittent claudication, and dyspnea were all associated with angina pectoris. In both sexes, angina pectoris was positively associated with body mass index. Males with diabetes had two times the prevalence of angina pectoris as males without diabetes; in females, diabetes was only weakly associated with angina pectoris. None of other major ischemic heart disease risk factors (blood pressure, serum lipids, or smoking) was associated with angina pectoris

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A cohort of 9,055 singleton pregnancies was identified by conventional urine tests or physician examination at the Kaiser Permanente Medical Care Program in Northern California in 1981–1982. Using life table methods, we estimated the cumulative risk of spontaneous abortion or fetal death through the end of pregnancy as 13.0% of all pregnancies surviving 1 week or more past the time of the first missed menses. This value was lower than the estimates of 1 5.1% and 16.0%, respectively, from two previous fetal life table studies conducted at Kaiser Permanente in prior decades, but similar to estimates from recent, smaller studies of early pregnancy diagnosed by human chorionic gonadotropin. The major difference in survival between the three Kaiser Permanente cohorts was in the earliest gestational week of observation, week 5 from the last menstrual period, where the older data were sparse and potentially biased. High loss rates during this week accounted for one-fourth to one-third of the cumulative risk observed in the older studies. Although the older cohorts were larger, the 1981–1982 cohort included five times and three times as many pregnancies under observation during week 5 from the last menstrual period, yielding more stable estimates for this period. Because of improved reliability of early pregnancy testing and an emphasis on early prenatal care, the mean gestational age at entry to the 1981–1982 cohort was 10.4 weeks from the last menstrual period compared to 14–3 weeks and 13.7 weeks for the older studies. All three studies showed a peak for risk of spontaneous abortion around weeks 10–12 from the last menstrual period

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

To explore the possible association between vaginal douching and tubal pregnancy, we interviewed 273 women who were diagnosed with tubal pregnancy at Group Health Cooperative between September 31, 1981 and October 1, 1986. Their responses were compared with responses of a random sample of 722 female members of Group Health Cooperative who were assumed to be at risk of becoming pregnant at the time the cases conceived. After adjusting for differences between cases and controls with regard to other measured risk factors, we found a modest increase in risk associated with having douched more than two times per year in the past (RR = 1.3, 95% CI: 0.9–1.8). Among women who had more than one sexual partner during their lifetime, however, the risk for those who had douched more than twice per year was somewhat higher (RR = 1.6, 95% CI: 1.1–2.3). There was an indication that women who had been exposed to Chlamydia trachomatis, as indicated by elevated antibody titers, may further increase their risk for tubal pregnancy by douching (RR = 2.4, 95% CI: 0.8–7.3). The associations found in other studies between douching and pelvic inflammatory disease, and between pelvic inflammatory disease and subsequent tubal pregnancy, argue that a relation between douching and tubal pregnancy might be anticipated. Our results offer further support for this hypothesis

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Standardized mortality ratios (SMRs) for occupational diseases are confounded by health differences between industrial and general populations. In 109 industrial cohorts largely free of work-related mortality, these selection effects were sizable for both malignant and nonmalignant outcomes. All-cancer SMRs were considerably less than 1.0 for many cohorts, and lung cancer was subject to almost as much selection-derived confounding as nonmalignant disease. Standardized proportional mortality ratios (PMRs) (approximated by relative SMRs (RSMRs)) were less confounded than SMRs in estimating occupational risk. PMRs appeared to overestimate cancer mortality on average by 6%, while SMRs underestimated by 13%. PMRs underestimated nonmalignant respiratory disease by 16 percent but SMRs underestimated by 39 percent. The sources of confounding, in addition to selection on health status at hire, most likely include social class. SMRs, in the absence of internal population comparisons, would fail to detect both malignant and nonmalignant work-related mortality in many industrial cohorts

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1991

数据来源: OVID