Joy L. Wood

The Effect of Age on the Association between Body-Mass Index and Mortality

BACKGROUND The effect of age on optimal body weight is controversial, and few studies have had adequate numbers of subjects to analyze mortality as a function of body-mass index across age groups. METHODS We studied mortality over 12 years among white men and women who participated in the American Cancer Societys Cancer Prevention Study I (from 1960 through 1972). The 62,116 men and 262,019 women included in this analysis had never smoked cigarettes, had no history of heart disease, stroke, or cancer (other than skin cancer) at base line in 1959-1960, and had no history of recent unintentional weight loss. The date and cause of death for subjects who died were determined from death certificates. The associations between body-mass index (defined as the weight in kilograms divided by the square of the height in meters) and mortality were examined for six age groups in analyses in which we adjusted for age, educational level, physical activity, and alcohol consumption. RESULTS Greater body-mass index was associated with higher mortality from all causes and from cardiovascular disease in men and women up to 75 years of age. However, the relative risk associated with greater body-mass index declined with age. For example, for mortality from cardiovascular disease, the relative risk associated with an increment of 1 in the body-mass index was 1.10 (95 percent confidence interval, 1.04 to 1.16) for 30-to-44-year-old men and 1.03 (95 percent confidence interval, 1.02 to 1.05) for 65-to-74-year-old men. For women, the corresponding relative risk estimates were 1.08 (95 percent confidence interval, 1.05 to 1.11) and 1.02 (95 percent confidence interval, 1.02 to 1.03). CONCLUSIONS Excess body weight increases the risk of death from any cause and from cardiovascular disease in adults between 30 and 74 years of age. The relative risk associated with greater body weight is higher among younger subjects.

Neighborhood Income, Health Insurance, and Prehospital Delay for Myocardial Infarction: The Atherosclerosis Risk in Communities Study

BACKGROUND Outcomes following an acute myocardial infarction (AMI) are generally more favorable if prehospital delay time is minimized. METHODS We examined the association of neighborhood household income (nINC) and health insurance status with prehospital delay among a weighted sample of 9700 men and women with a validated, definite, or probable AMI in the Atherosclerosis Risk in Communities (ARIC) community surveillance study (1993-2002). Weighted multinomial regression with generalized estimation equations was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and to account for the clustering of patients within census tracts. RESULTS Low nINC was associated with a higher odds of long vs short delay (OR, 1.46; 95% CI, 1.09-1.96) and medium vs short delay (OR, 1.43; 95% CI, 1.12-1.81) compared with high nINC in a model including age, sex, race, diabetes, hypertension, presence of chest pain, arrival at the hospital via emergency medical service, distance from residence to hospital, study community, and year of AMI event. Meanwhile, compared with patients with prepaid insurance or prepaid plus Medicare, patients with Medicaid were more likely to have a long vs short delay (OR, 1.87; 95% CI, 1.10-3.19) and a medium vs short delay (OR, 1.76; 95% CI, 1.13-2.74). CONCLUSIONS Both low nINC and being a Medicaid recipient are associated with longer prehospital delay. Reducing socioeconomic and insurance disparities in prehospital delay is critical because excess delay time may hinder effective care for AMI.

A case control study of multiple myeloma at four nuclear facilities.

PURPOSE Reported elevations of multiple myeloma among nuclear workers exposed to external penetrating ionizing radiation, based on small numbers of cases, prompted this multi-facility study of workers at US Department of Energy facilities. METHODS Ninety-eight multiple myeloma deaths and 391 age-matched controls were selected from the combined roster of 115,143 workers hired before 1979 at Hanford, Los Alamos National Laboratory, Oak Ridge National Laboratory, and the Savannah River site. These workers were followed for vital status through 1990 (1986 for Hanford). Demographic, work history, and occupational exposure data were derived from personnel, occupational medicine, industrial hygiene, and health physics records. Exposure-disease associations were evaluated using conditional logistic regression. RESULTS Cases were disproportionately African American, male, and hired prior to 1948. Lifetime cumulative whole body ionizing radiation dose was not associated with multiple myeloma, however, there was a significant effect of age at exposure, with positive associations between multiple myeloma and doses received at older ages. Dose response associations increased in magnitude with exposure age (from 40 to 50) and lag assumption (from 5 to 15 years), while a likelihood ratio goodness of fit test reached the highest value for cumulative doses received at ages above 45 with a 5-year lag (X2=5.43,1 df; relative risk = 6.9% per 10 mSv). Dose response associations persisted with adjustment for potential confounders. CONCLUSIONS Multiple myeloma was associated with low level whole body penetrating ionizing radiation doses at older ages. The exposure age effect is at odds with interpretations of A-bomb survivor studies but in agreement with several studies of cancer among nuclear workers.

Neighborhood socioeconomic status, Medicaid coverage and medical management of myocardial infarction: Atherosclerosis risk in communities (ARIC) community surveillance

BackgroundPharmacologic treatments are efficacious in reducing post-myocardial infarction (MI) morbidity and mortality. The potential influence of socioeconomic factors on the receipt of pharmacologic therapy has not been systematically examined, even though healthcare utilization likely influences morbidity and mortality post-MI. This study aims to investigate the association between socioeconomic factors and receipt of evidence-based treatments post-MI in a community surveillance setting.MethodsWe evaluated the association of census tract-level neighborhood household income (nINC) and Medicaid coverage with pharmacologic treatments (aspirin, beta [β]-blockers and angiotensin converting enzyme [ACE] inhibitors; optimal therapy, defined as receipt of two or more treatments) received during hospitalization or at discharge among 9,608 MI events in the ARIC community surveillance study (1993-2002). Prevalence ratios (PR, 95% CI), adjusted for the clustering of hospitalized MI events within census tracts and within patients, were estimated using Poisson regression.ResultsSeventy-eight percent of patients received optimal therapy. Low nINC was associated with a lower likelihood of receiving β-blockers (0.93, 0.87-0.98) and a higher likelihood of receiving ACE inhibitors (1.13, 1.04-1.22), compared to high nINC. Patients with Medicaid coverage were less likely to receive aspirin (0.92, 0.87-0.98), compared to patients without Medicaid coverage. These findings were independent of other key covariates.ConclusionsnINC and Medicaid coverage may be two of several socioeconomic factors influencing the complexities of medical care practice patterns.

Neighborhood disparities in incident hospitalized myocardial infarction in four U.S. communities: the ARIC surveillance study.

PURPOSE Hospital-based surveillance of myocardial infarction (MI) in the United States (U.S.) typically includes age, gender, and race, but not socioeconomic status (SES). We examined the association between neighborhood median household income (nINC) and incident hospitalized MI in four U.S. communities (1993-2002). METHODS Average annual indirect age-standardized MI rates were calculated using community-specific and community-wide nINC tertiles. Poisson generalized linear mixed models were used to calculate MI incidence rate ratios by tertile of census tract nINC (high nINC group referent). RESULTS Within community, and among all race-gender groups, those living in low nINC neighborhoods had an increased risk of MI compared to those living in high nINC neighborhoods. This association was present when both community-specific and community-wide nINC cut points were used. Blacks and, to a lesser extent, women, were disproportionately represented in low nINC neighborhoods, resulting in a higher absolute burden of MI in blacks and women living in low compared with high nINC neighborhoods. CONCLUSIONS These findings suggest a need for the joint consideration of racial, gender, and social disparities in interventions aimed at preventing coronary heart disease.

Long-term association between self-reported signs and symptoms and heart failure hospitalizations: the Atherosclerosis Risk In Communities (ARIC) Study

Although studies of the accuracy of heart failure (HF) classification scoring systems are available, few have examined their performance when restricted to self‐reported items.

Change in the prevalence of leisure activity with the number of activities recalled

PURPOSE The purpose of this study was to examine how the estimated prevalence of leisure activity changed when respondents self-reported up to four activities, compared with using information only from the respondents one, two, and three most commonly performed leisure activities. METHODS Information on leisure activities, sociodemographics, and body mass index (BMI) categories was collected in the year 2000 during a telephone interview of 1813 randomly selected adults living in six North Carolina counties. Recommended activity was defined as moderate leisure activity > or =5x wk(-1) for > or =30 min per session or vigorous leisure activity > or =3x wk(-1) for > or =20 min per session. RESULTS Among respondents, 32.1% reported participation in no leisure activity, 41.7% reported one activity, 21.5% reported two activities, 3.8% reported three activities, and 0.9% reported four activities during the past month. The largest change in prevalence occurred when using two activities compared with one activity for recommended activity, overall and by sociodemographic and BMI categories. The prevalence of recommended activity determined by using 1, 2, 3, or 4 activities was 21.0%, 26.0%, 26.5%, and 26.7%, respectively. CONCLUSION In this study, collecting information on two leisure activities was the most efficient balance for population specific accuracy of recommended activity.