Journal of chronic diseases最新文献

To confirm the reported association of body fat distribution with cardiovascular disease, diabetes, blood pressure and serum cholesterol, data from the 1960-62 Health Examination Survey were analyzed. In this sample drawn from the noninstitutionalized population of the United States aged 18–79, mean values of two indices of upper versus lower body fat distribution increased steadily with age. Men had higher values than women, and black women had higher values than white women. Higher values of the indices were significantly associated with higher blood pressure, post-load serum glucose and greater prevalence of definite hypertension and definite hypertensive heart disease independent of multiple confounders. Associations with higher serum cholesterol and definite coronary heart disease prevalence were independent of overall ponderosity but not of age and multiple other confounders. Greater abdominal relative to lower body fat deposits were independently associated with increased cardiovascular risk in men and women, blacks and whites.

Prognostic studies hinge on the assembly of a proper inception cohort. The stepwise assembly of a “true” inception cohort of hypertension complicating pregnancy is reported. Standard assembly procedures would have resulted in the preferential reporting of the severest cases of the prognostically worst categories of disease. The less severe cases would have been missed. Prognostic studies should utilize and report a method for assessing potential missed cases, such as a random selection of records for independent review.

The impact of disease and treatment on patients' lives is frequently measured by endpoints such as health status, well being and quality of life. The objective of this paper is to introduce a new but related outcome concept termed “reintegration to normal living” and to compare it to the quality of life. The concept of “reintegration” is closely allied to functional performance. Like quality of life, it is important to measure when therapeutic goals cannot include a cure but are directed at controlling the disease process or fostering compensation for impairment. A Reintegration to Normal Living (RNL) Index has been developed. Although more limited in conceptual focus, its content is similar to global quality of life measures. It is internally consistent, demonstrates content and construct validity, can be completed by patients or significant others and is sensitive to changes in patient status. The degree of reintegration achieved by patients after an incapacitating illness is seen as contributing to the quality of their lives.

Clinical trials are commonly performed in surgery to assess the efficacy of one or more treatments. Many therapies result in only partial or temporary improvement, rather than cure. Others sharply affect the quality of patients' lives or of their deaths. For most interventions, it is important to document effects on quality of life as well as morbidity and mortality rates. Yet, a review of the literature reveals that very few surgical trials consider quality of life variables as outcome measures. Surgical investigators in areas like cancer, inflammatory bowel disease, end stage renal disease, and cardiac disease have examined quality of life issues extensively using a variety of scales and indices. However, most studies on quality of life are hampered by poor design and inadequate methods of assessment. Failure to evaluate quality of life variables prevents the recognition and full use of potentially beneficial therapies and the rejection of potentially harmful ones.

We used two methods to examine how lung cancer death rates vary with cumulative exposures to radiation and tobacco among U.S. uranium miners. We assumed that exposures act proportionately on age-specific death rates among nonsmokers who are unexposed to uranium. The two methods produced similar results when death rate ratios were taken to be the product of radiation and tobacco effects. The estimates were discrepant when death rate ratios were taken to be the sum of radiation and tobacco effects. Both methods indicated better fit for the multiplicative model, as judged by the maximized loglikelihood values. Death rates estimated in this way for white males in the absence of mining and smoking increased only weakly with age. This weak relation suggests that our models of death rates fit poorly. It may be that cumulative exposures are inappropriate measures of the effects of radiation and tobacco on lung cancer death rates.

The most central epidemiological feature of cancers of the breast, ovary and endometrium is the enormous protective effect of menopause. Simple mathematical “models” of the age-incidence of these tumours suggests that their incidence by age 70 would be between 4 and 8-fold increased if women continued to menstruate into old age. Using the notion of “effective cell-cycle time” to explain this phenomenon, different “models” are constructed for each of these three tumour sites and shown to provide an excellent description of most of the known epidemiology of each of the cancers, and to provide a basis for predicting the long-term effects of various factors on the risk of these diseases. In particular, the model suggests that 5 years of combination-type oral contraceptive use will approximately halve the lifelong risk of both ovarian cancer and endometrial cancer.

Assessing latency for neoplastic diseases is crucial for determining the causal effects of a complex mix of carcinogenic exposures. An initial assessment of cancer risks in a U.S. tire and rubber plant revealed a significant SMR of 140 for prostatic cancer. Using an industry-based, case-control death certificate study of prostatic malignancies, we found matched odds ratios of about 3 (p < 0.025) for Batch Preparation, the work area with the greatest exposure to carbon black, solvents, and heavy metal oxides. To assess latency, we used the matched case-control series to calculate annual estimates of the odds ratio by determining the proportion of cases and controls employed for greater than 1 month in Batch Preparation during each year under study. This approach produced a plot with great fluctuations. To reduce variability in the resulting curve, a method was developed that measured the “etiologic fraction,” which is its highest point represents an estimate of the peak of the latency distribution. For Batch Preparation the modal point was 29 years before death with the greatest risk occurring from employment in the mid-1940's. The latency method allows risk assessment for time and year of greatest exposure difference, thus suggesting appropriate prevention strategies. Applications of this method for other types of studies and exposures are discussed.