Lung disease mortality in the United States: the National Longitudinal Mortality Study.

SETTING: The National Longitudinal Mortality Study (NLMS) offers the advantage of assessing mortality in a representative population of the United States. OBJECTIVE: To evaluate health disparities associated with lung cancer and chronic obstructive pulmonary disease (COPD) mortality in the United States and whether these associations are similar between these outcomes. DESIGN: The NLMS is a prospective study. Data from NLMS cohort years 1985, 1992, 1993, 1995 and 1996 were included, representing nearly 1.5 million person-years. Lung cancer and COPD mortality relative risks (RRs) from Cox regression analysis, including residential characteristics, marital status, education, health insurance and family income, were evaluated. RESULTS: By 1998, 1273 lung cancer deaths and 772 COPD deaths occurred. Lung cancer mortality rates were approximately two times higher than COPD mortality rates among race and ethnic groups. Cox regression analysis revealed that low education (RR = 1.77, significant, P = 0.01) and low family income (RR = 1.50, significant, P = 0.01) are associated with lung cancer and COPD mortality, controlling for age, race/ethnicity, sex and smoking status. CONCLUSIONS: COPD and lung cancer mortality have similar associations with health disparity indicators in the NLMS data, with some differences in the magnitude of the effect.

Cancer surveillance series: interpreting trends in prostate cancer--part I: Evidence of the effects of screening in recent prostate cancer incidence, mortality, and survival rates.

BACKGROUND: The prostate-specific antigen test was approved by the U.S. Food and Drug Administration in 1986 to monitor the disease status in patients with prostate cancer and, in 1994, to aid in prostate cancer detection. However, after 1986, the test was performed on many men who had not been previously diagnosed with prostate cancer, apparently resulting in the diagnosis of a substantial number of early tumors. Our purpose is to provide insight into the effect of screening on prostate cancer rates. Detailed data are presented for whites because the size of the population allows for calculating statistically reliable rates; however, similar overall trends are seen for African-Americans and other races. METHODS: Prostate cancer incidence data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program and mortality data from the National Center for Health Statistics were analyzed. RESULTS/CONCLUSIONS: The following findings are consistent with a screening effect: 1) the recent decrease since 1991 in the incidence of distant stage disease, after not having been perturbed by screening; 2) the decline in the incidence of earlier stage disease beginning the following year (i.e., 1992); 3) the recent increases and decreases in prostate cancer incidence and mortality by age that appear to indicate a calendar period effect; and 4) trends in the incidence of distant stage disease by tumor grade and trends in the survival of patients with distant stage disease by calendar year that provide suggestive evidence of the tendency of screening to detect slower growing tumors. IMPLICATIONS: The decline in the incidence of distant stage disease holds the promise that testing for prostate-specific antigen may lead to a sustained decline in prostate cancer mortality. However, population data are complex, and it is difficult to confidently attribute relatively small changes in mortality to any one cause.

Quality-of-life outcomes after primary androgen deprivation therapy: results from the Prostate Cancer Outcomes Study.

PURPOSE: To compare health-related quality-of-life outcomes after primary androgen deprivation (AD) therapy with orchiectomy versus luteinizing hormone-releasing hormone (LHRH) agonists for patients with prostate cancer. PATIENTS AND METHODS: Men (n = 431) newly diagnosed with all stages of prostate cancer from six geographic regions who participated in the Prostate Cancer Outcomes Study and who received primary AD therapy but no other treatments within 12 months of initial diagnosis were included in a study of health outcomes. Comparisons were statistically adjusted for patient sociodemographic and clinical characteristics, timing of therapy, and use of combined androgen blockade. RESULTS: More than half of the patients receiving primary AD therapy had been initially diagnosed with clinically localized prostate cancer. Among these patients, almost two thirds were at high risk of progression on the basis of prognostic factors. Sexual function outcomes were similar by treatment group both before and after implementation of AD therapy. LHRH patients reported more breast swelling than did orchiectomy patients (24.9% v 9.7%, P <.01). LHRH patients reported more physical discomfort and worry because of cancer or its treatment than did orchiectomy patients. LHRH patients assessed their overall health as fair or poor more frequently than did orchiectomy patients (35.4% v 28.1%, P =.01) and also were less likely to consider themselves free of prostate cancer after treatment. CONCLUSION: Most endocrine-related health outcomes are similar after surgical versus medical primary hormonal therapy. Stage at diagnosis had little effect on outcomes. These results provide representative information comparing surgical and medical AD therapy that may be used by physicians and patients to inform treatment decisions.

Physical activity and incidence of coronary heart disease in middle-aged women and men.

Few studies of physical activity and coronary heart disease (CHD) have included women or blacks. We examined this association in a biracial cohort of 45- to 64-yr-old adults. We related the sports, leisure, and work indices developed by J. A. H. Baecke et al. to CHD incident events (N = 97 in women, N = 223 in men) over 4-7 yr in the Atherosclerosis Risk in Communities study. The age-, race-, and field center-adjusted relative risk of CHD was 0.73 in women and 0.82 in men per each standard deviation increment in the sports index (P < 0.05). For the leisure index, these relative risks were 0.78 for both sexes (P < 0.05). The work index was not associated with CHD. These inverse associations held for non-blacks, but there was no association between the sport or leisure indices and CHD among blacks. Vigorous sports participation was strongly inversely associated with CHD, but an independent contribution of nonvigorous activity (e.g., walking) could not be demonstrated conclusively. Adjustment for other risk factors attenuated the relative risks, as one might expect if these risk factors mediated any protective effect of physical activity. Our findings reinforce evidence that regular physical activity should protect women, as well as men, from CHD. Explanations for no association among blacks, if real, are needed.

A marginal mixed baseline hazards model for multivariate failure time data.

In multivariate failure time data analysis, a marginal regression modeling approach is often preferred to avoid assumptions on the dependence structure among correlated failure times. In this paper, a marginal mixed baseline hazards model is introduced. Estimating equations are proposed for the estimation of the marginal hazard ratio parameters. The proposed estimators are shown to be consistent and asymptotically Gaussian with a robust covariance matrix that can be consistently estimated. Simulation studies indicate the adequacy of the proposed methodology for practical sample sizes. The methodology is illustrated with a data set from the Framingham Heart Study.

Association of coronary heart disease incidence with carotid arterial wall thickness and major risk factors: the Atherosclerosis Risk in Communities (ARIC) Study, 1987-1993.

Few studies have determined whether greater carotid artery intima-media thickness (IMT) in asymptomatic individuals is associated prospectively with increased risk of coronary heart disease (CHD). In the Atherosclerosis Risk in Communities Study, carotid IMT, an index of generalized atherosclerosis, was defined as the mean of IMT measurements at six sites of the carotid arteries using B-mode ultrasound. The authors assessed its relation to CHD incidence over 4-7 years of follow-up (1987-1993) in four US communities (Forsyth County, North Carolina; Jackson, Mississippi; Minneapolis, Minnesota; and Washington County, Maryland) from samples of 7,289 women and 5,552 men aged 45-64 years who were free of clinical CHD at baseline. There were 96 incident events for women and 194 for men. In sex-specific Cox proportional hazards models adjusted only for age, race, and center, the hazard rate ratio comparing extreme mean IMT (> or = 1 mm) to not extreme (< 1 mm) was 5.07 for women (95% confidence interval 3.08-8.36) and 1.85 for men (95% confidence interval 1.28-2.69). The relation was graded (monotonic), and models with cubic splines indicated significant nonlinearity. The strength of the association was reduced by including major CHD risk factors, but remained elevated at higher IMT. Up to 1 mm mean IMT, women had lower adjusted annual event rates than did men, but above 1 mm their event rate was closer to that of men. Thus, mean carotid IMT is a noninvasive predictor of future CHD incidence.

Partitioning linear trends in age-adjusted rates.

OBJECTIVE: Surveillance of chronic diseases includes monitoring trends in age-adjusted rates in the general population. Statistics that are calculated to describe and compare trends include the annual percent change and the percent change for a specified time period. However, it is also of interest to determine the contribution specific diseases make to an overall trend in order to better understand the impact of interventions and changes in the prevalence of risk factors. The objective here is to provide a method for partitioning a linear trend in age-adjusted rates into disease-specific components. METHODS: The method presented is based on linear regression. The decreasing trend in age-adjusted cancer mortality rates for the total United States during the period 1991-96 is analyzed to illustrate the method. RESULTS: Trends in mortality for cancers of the colon/rectum, breast, lung/bronchus, and prostate are found to be responsible for 75% of the decreasing trend in cancer mortality. CONCLUSIONS: It is possible to partition an overall trend in age-adjusted rates under the assumption that it and the trends for all mutually exclusive and exhaustive subgroups of interest are linear.

Carotid wall thickness is predictive of incident clinical stroke: the Atherosclerosis Risk in Communities (ARIC) study.

Few studies have determined whether carotid artery intima-media thickness (IMT) is associated prospectively with risk of first ischemic stroke. In the Atherosclerosis Risk in Communities Study, carotid IMT, an index of generalized atherosclerosis, was defined as the mean of IMT measured by B-mode ultrasonography at six sites of the carotid arteries. The authors assessed the relation of mean IMT to stroke incidence over 6-9 years' follow-up (1987-1995) among 7,865 women and 6,349 men aged 45-64 years without prior stroke at baseline in four US communities. There were 90 incident ischemic stroke events for women and 109 for men. In sex-specific Cox proportional hazards models adjusting only for age, race, and community, the hazard rate ratios comparing extreme mean IMT values (> or =1 mm) to values less than 0.6 mm were 8.5 for women (95% confidence interval: 3.5, 20.7) and 3.6 for men (95% confidence interval: 1.5, 9.2). The relation was graded, and models with cubic splines indicated significant nonlinearity, with hazards increasing more rapidly at lower IMTs than at higher IMTs. Thus, models using linear IMT values substantially underestimate the strength of the association at lower IMTs. The strength of the association was reduced by the inclusion of putative stroke risk factors, but it remained elevated at higher IMTs. Hence, mean carotid IMT is a noninvasive predictor of future ischemic stroke incidence.

Comparison of self-reported initial treatment with medical records: results from the prostate cancer outcomes study.

Medical records are generally accepted as the most accurate source of information documenting cancer treatments. However, as the health care system becomes more decentralized and more cancer care is delivered in outpatient settings, it is increasingly difficult and expensive to review records from the many surgeons and medical/radiation oncologists who administer cancer therapies in the community setting. Using 1994-1995 data, the authors compared initial treatment for prostate cancer self-reported (from a mailed questionnaire or telephone/in-person interview) by 3,196 US men in the population-based Prostate Cancer Outcomes Study with information obtained from medical records. Agreement between self-reports and medical records varied by type of treatment. Generally, agreement was excellent for more invasive procedures such as prostatectomy or radiation (kappa values > 0.8), with decreasing agreement for hormone shots and pills (kappa values < 0.7). If the medical record abstract is assumed to be the "gold standard," the estimated sensitivity was generally high (>80%) for prostatectomy and radiation but low (68%) for hormone pills, although the estimated specificity was 90% or greater for all treatments. These results can serve as a useful guide to researchers contemplating the use of surveys as an alternative to medical record abstraction to ascertain treatment in studies of patient outcomes.

Methods for evaluation of retinal microvascular abnormalities associated with hypertension/sclerosis in the Atherosclerosis Risk in Communities Study.

OBJECTIVE: To develop protocols to photograph and evaluate retinal vascular abnormalities in the Atherosclerosis Risk in Communities (ARIC) Study; to test reproducibility of the grading system; and to explore the relationship of these microvascular changes with blood pressure. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Among 4 examination centers, 11,114 participants (48-73 years of age) at their third triennial examination, after excluding persons with diabetes from this analysis. METHODS: One eye of each participant was photographed by technicians with nonmydriatic fundus cameras. Reading center graders evaluated focal arteriolar narrowing, arteriovenous (AV) nicking, and retinopathy by examining slides on a light box and measured diameters of all vessels in a zone surrounding the optic disc on enhanced digitized images. To gauge generalized narrowing, vessel diameters were combined into central arteriolar and venular equivalents with formulas adjusting for branching, and the ratio of equivalents (A/V ratio) was calculated. MAIN OUTCOME MEASURES: Retinal vascular abnormalities, mean arteriolar blood pressure (MABP). RESULTS: Among 11,114 participants, photographs were obtained of 99%, with quality sufficient to perform retinal evaluations in 81%. In the 9040 subjects with usable photographs, A/V ratio (lower values indicate generalized arteriolar narrowing) ranged from 0.57 to 1.22 (median = 0.84, interquartile range = 0.10), focal arteriolar narrowing was found in 7%, AV nicking in 6%, and retinopathy in 4%. Because of attrition of subjects and limitation of methods, prevalence of abnormality was likely underestimated. Controlling for gender, race, age, and smoking status, these retinal changes were associated with higher blood pressure. For every 10-mmHg increase in MABP, A/V ratio decreased by 0.02 unit (P < 0.0001), focal arteriolar narrowing had an odds ratio (OR) of 2.00 (95% confidence interval [CI] = 1.87-2.14), AV nicking had an OR of 1.25 (95% CI = 1.16-1.34), and retinopathy had an OR of 1.25 (95% CI = 1.15-1.37). For any degree of generalized narrowing, individuals with focal narrowing had MABP approximately 8 mmHg higher than those without (P < 0.0001). Masked replicate assessment of a sample found the following reproducibility: for A/V ratio, correlation coefficient = 0.79 and median absolute difference = 0.03; for focal arteriolar narrowing, kappa = 0.45; for AV nicking, kappa = 0.61; and for retinopathy, kappa = 0.89. CONCLUSION: Protocols have been developed for nonmydriatic fundus photography and for evaluation of retinal vascular abnormalities. Several microvascular changes were significantly associated with higher blood pressure; follow-up will show whether these are predictive of later cerebrovascular or cardiovascular disease independently of other known risk factors.