Validity of self-reported hypertension in the National Health and Nutrition Examination Survey III, 1988-1991.

BACKGROUND: The National Health and Nutrition Examination Survey (NHANES) is the main data source for hypertension surveillance. However, because of a gap of almost 10 years between each NHANES, self-reported data from annual surveys need to be examined as an alternative data source. This study analyzes the validity of self-reported hypertension in a national sample of non-Hispanic whites, non-Hispanic blacks, and Mexican-Americans. METHODS: Sensitivity, specificity, and predictive values positive (PVP) and negative (PVN) of self-reported hypertension were calculated against two definitions of hypertension: the definition recommended by the Third Joint National Committee on Hypertension, JNC III (blood pressure > or = 140/90 and/or taking antihypertension medication) and a broader definition including control with lifestyle modifications. Data used come from the NHANES III, 1988-1991. RESULTS: Overall test characteristics using the JNC III definition are sensitivity 71%, specificity 90%, PVP 72%, and PVN 89%. Test characteristics were consistently higher for the broad than for the JNC III definition. Validity of self-reported hypertension is higher among women than among men and among persons with a medical visit during the past year than among those with no visits: validity was lowest among Mexican-American men. Due to the similarity between sensitivity and PVP, the prevalence of self-reported hypertension is nearly equal to the prevalence of JNC III-defined hypertension. CONCLUSIONS: Self-reported hypertension may be used for surveillance of hypertension trends, in the absence of measured blood pressure, among non-Hispanic whites and non-Hispanic black women and persons with a medical visit in the past year. Validation should be repeated with each NHANES.

Hypertension and other cardiovascular disease risk factors among Mexican Americans, Cuban Americans, and Puerto Ricans from the Hispanic Health and Nutrition Examination Survey.

DESPITE THEIR HIGHER PREVALENCE of obesity and diabetes, Hispanics have lower or equal rates of hypertension than non-Hispanic whites (1-4). Healthy People 2000 objectives call for increasing the proportion of hypertensive men whose blood pressure is under control to at least 40%. In addition, the objectives recommend reducing the prevalence of overweight to 41% among hypertensive women, and to 35% among hypertensive men (5). The Hispanic Health and Nutrition Examination Survey (HHANES) collected data on Mexican Americans (MA), Cuban Americans (CA), and Puerto Ricans (PR) living in the continental United States. A trained physician measured systolic (SBP) and diastolic (DBP) blood pressure twice in one visit. Our findings provide data to assess baseline estimates for several Healthy People 2000 objectives among Hispanics. Based on criteria from The Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC-V), we found Hispanic women to have higher rates of awareness, treatment, and control of hypertension than men. Only 8% of MA and PR men and 9% of CA men who were hypertensive had their high blood pressure under control. The prevalence of overweight among hypertensive men ranged from 39% to 60%; and among hypertensive women, from 44% to 74%. Hispanic women with six or fewer years of education had higher prevalence of hypertension and other cardiovascular disease (CVD) risk factors. Future research should investigate the socioeconomic factors associated with the presence of these risk factors.

Hodgkin's disease and Vietnam service.

Earlier studies that showed an association between exposure to phenoxy herbicides and the risk of malignant lymphomas have sparked concerns among Vietnam veterans over Agent Orange exposure. The Department of Veterans Affairs (VA) undertook a hospital-based case-control study to examine the association between military service in Vietnam and several histologic types of malignant lymphomas. This is a report of 283 Vietnam-era veteran patients who were treated in one of 172 VA hospitals from 1969 to 1985 with a diagnosis of Hodgkin's Disease (HD). Four hundred and four Vietnam-era veteran patients with diagnosis other than malignant lymphoma served as a comparison group. Military service in Vietnam was not associated with any significant increase in the risk of HD (adjusted odds ratio = 1.28; 95% confidence interval = 0.94, 1.76). Surrogate measures of potential Agent Orange exposure such as service in a specific military branch, in a certain region within Vietnam, in a combat role, or extended Vietnam service time were not associated with any significant increased risk of HD.

Trends in the prevalence, awareness, treatment, and control of hypertension in the adult US population. Data from the health examination surveys, 1960 to 1991.

The objective of this study was to describe secular trends in the distribution of blood pressure and prevalence of hypertension in US adults and changes in rates of awareness, treatment, and control of hypertension. The study design comprised nationally representative cross-sectional surveys with both an in-person interview and a medical examination that included blood pressure measurement. Between 6530 and 13,645 adults, aged 18 through 74 years, were examined in each of four separate national surveys during 1960-1962, 1971-1974, 1976-1980, and 1988-1991. Protocols for blood pressure measurement varied significantly across the surveys and are presented in detail. Between the first (1971-1974) and second (1976-1980) National Health and Nutrition Examination Surveys (NHANES I and NHANES II, respectively), age-adjusted prevalence of hypertension at > or = 160/95 mm Hg remained stable at approximately 20%. In NHANES III (1988-1991), it was 14.2%. Age-adjusted prevalence at > or = 140/90 mm Hg peaked at 36.3% in NHANES I and declined to 20.4% in NHANES III. Age-specific prevalence rates have decreased for every age-sex-race subgroup except for black men aged 50 and older. Age-adjusted mean systolic pressures declined progressively from 131 mm Hg at the NHANES I examination to 119 mm Hg at the NHANES III examination. The mean systolic and diastolic pressures of every sex-race subgroup declined between NHANES II and III (3 to 6 mm Hg systolic, 6 to 9 mm Hg diastolic). During the interval between NHANES II and III, the threshold for defining hypertension was changed from 160/95 to 140/90 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of hypertension in the US adult population. Results from the Third National Health and Nutrition Examination Survey, 1988-1991.

The purpose of this study was to estimate the current prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the US adult population. The study used a cross-sectional survey of the civilian, noninstitutionalized population of the United States, including an in-home interview and a clinic examination, each of which included measurement of blood pressure. Data for 9901 participants 18 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey, collected from 1988 through 1991, were used. Twenty-four percent of the US adult population representing 43,186,000 persons had hypertension. The age-adjusted prevalence in the non-Hispanic black, non-Hispanic white, and Mexican American populations was 32.4%, 23.3%, and 22.6%, respectively. Overall, two thirds of the population with hypertension were aware of their diagnosis (69%), and a majority were taking prescribed medication (53%). Only one third of Mexican Americans with hypertension were being treated (35%), and only 14% achieved control in contrast to 25% and 24% of the non-Hispanic black and non-Hispanic white populations with hypertension, respectively. Almost 13 million adults classified as being normotensive reported being told on one or more occasions that they had hypertension; 51% of this group reported current adherence to lifestyle changes to control their hypertension. Hypertension continues to be a common finding in the general population. Awareness, treatment, and control of hypertension have improved substantially since the 1976-1980 National Health and Nutrition Examination Survey but continue to be suboptimal, especially in Mexican Americans.(ABSTRACT TRUNCATED AT 250 WORDS)

The third National Health and Nutrition Examination Survey: contributing data on aging and health.

The third National Health and Nutrition Examination Survey (NHANES III, 1988-94) is the most recent in a series of national examination studies conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention. Prior to NHANES III the upper age limit was 74; the upper age limit was removed for NHANES III. Persons 60 years and older in the black and Mexican American populations, and those 60-69, 70-79, and 80 years and older in the white population were oversampled. The NHANES III component for older persons provides a multidimensional overview of physical health status and aspects of functional health status. The key components for older persons are: Osteoporosis, arthritis, nutrition, cardiovascular disease, pulmonary disease, and physical, cognitive, and social function.

Declining serum total cholesterol levels among US adults. The National Health and Nutrition Examination Surveys.

OBJECTIVE: To examine the secular trend in serum total cholesterol levels of the US adult population. DESIGN: Nationally representative cross-sectional surveys with both an in person interview and a medical examination that included the measurement of blood lipid levels. SETTING/PARTICIPANTS: Between 6000 and 13,000 adults aged 20 through 74 years examined in each of four separate national surveys during 1960 through 1962, 1971 through 1974, 1976 through 1980, and 1988 through 1991. RESULTS: Mean serum total cholesterol levels in US adults aged 20 through 74 years have consistently declined over the time period 1960 through 1991. More than half of the decline occurred during the time period 1976 through 1991. This decline occurred across the entire distribution of serum cholesterol levels and in all age-sex groups. High-density lipoprotein cholesterol and very low-density lipoprotein cholesterol levels have not changed, suggesting that the decline in total cholesterol levels is due to a decline in low-density lipoprotein cholesterol levels. CONCLUSIONS: These results document a continuing and substantial decline in serum cholesterol levels among US adults. They suggest that public health programs, designed to reduce cholesterol levels, are proving successful. The observed downward trend in serum cholesterol levels has coincided with a continuing decline in coronary heart disease mortality. These observations suggest that the Healthy People 2000 goal of reducing the mean serum cholesterol level of US adults to no more than 200 mg/dL (5.17 mmol/L) is attainable.

Prevalence of high blood cholesterol among US adults. An update based on guidelines from the second report of the National Cholesterol Education Program Adult Treatment Panel.

OBJECTIVE: To estimate the current levels and trends in the proportion of US adults with high blood cholesterol based on guidelines from the second report of the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP II). DESIGN: Nationally representative cross-sectional surveys. SETTING/PARTICIPANTS: Data for 7775 participants 20 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey (NHANES III) (data collected from 1988 through 1991) and for 9797 participants 20 through 74 years of age from NHANES II (data collected from 1976 through 1980) were used. RESULTS: From the data collection period in NHANES II (1976 through 1980) to the period in NHANES III (1988 through 1991), the proportion of adults with high blood cholesterol levels (> or = 240 mg/dL [6.21 mmol bd) fell from 26% to 20%, while the proportion with desirable levels (< 200 mg/dL [5.17 mmol/L]) rose from 44% to 49%. Currently, using the ATP II guidelines and NHANES III data, 40% of all adults 20 years of age and older would require fasting lipoprotein analysis; and 29% of all adults would be candidates for dietary therapy (as compared with 36%, using NHANES II data). Based on 1990 population data, it is estimated that approximately 52 million Americans 20 years of age and older would be candidates for dietary therapy. Assuming that dietary intervention would reduce low-density lipoprotein (LDL) cholesterol levels by 10%, as many as 7% of all adult Americans (approximately 12.7 million) might be candidates for cholesterol-lowering drugs. This estimate reflects approximately 4 million adults with established coronary heart disease, of whom half are aged 65 years and older, and up to 8.7 million adults without established coronary heart disease, of whom up to 3.1 million are aged 65 years and older. CONCLUSIONS: Substantial progress has been made in reducing the prevalence of high blood cholesterol; yet a large proportion of all adults, approximately 29%, require dietary intervention for high blood cholesterol.

The National Health and Nutrition Examination Survey III: describing the health and nutritional status of older Americans.

The National Health and Nutrition Examination III will provide important data for examination of the health and nutritional status of persons in the U.S. Innovations in the study, particularly the inclusion of persons over age 74 and the focus of the survey on the major chronic diseases of old age, will enhance the value for older persons. Response rates for phase 1 (1988-1991) show that about 80% of all older subjects agreed to the interview; examination rates declined with age, but the use of a home examination increased the response rate for those aged 75 or older by about 9% to 67% for men and about 62% for women. Analytic plans include examination of the effect of nutrition on health, as well as the effect of health status on the distribution of nutritional risk factors in old age.

Non-Hodgkin's lymphoma among Vietnam veterans.

In light of findings suggesting an increase in the risk for non-Hodgkin's lymphoma among men exposed to phenoxyherbicides and concerns among veterans over Agent Orange exposure, a hospital-based case-control study was undertaken to examine the association between military service in Vietnam and non-Hodgkin's lymphoma. The cases consisted of 201 Vietnam-era veteran patients who were treated in one of 172 Department of Veterans Affairs hospitals from 1969 through 1985 with a diagnosis of non-Hodgkin's lymphoma. 358 Vietnam-era veteran patients with a diagnosis other than malignant lymphoma served as a comparison group. Military service information was obtained from a review of the veteran's military personnel records. Service in Vietnam did not increase the risk of non-Hodgkin's lymphoma either in general (branch adjusted odds ratio = 1.03, 95% confidence interval = 0.70-1.50) or with increased latency period as defined as the duration in years from first service in Vietnam to hospital discharge. Surrogate measures of potential Agent Orange exposure such as service in a specific military branch, in a certain region within Vietnam, or in a combat role as determined by military occupational speciality were not associated with any increased risk of non-Hodgkin's lymphoma.

Data collection frequency effect in the National Medical Care Expenditure Survey.

The National Medical Care Expenditure Survey (NMCES) was characterized by a longitudinal survey design, with data collection targeted to five points in time covering the survey year. Field conditions did not allow for all interviews to be conducted over the targeted time periods. A subset of sampled households (holdovers) were not contacted for a particular wave of the survey and data were gathered at the subsequent time period for the two time intervals that were spanned. National estimates for a representative set of health care utilization and expenditure measures were derived from the sample of holdovers and compared with estimates derived from the respondents with five complete waves of data collection. Controlling for relevant predispositional factors in the estimation of health care utilization and expenditure measures, a test for data collection frequency effect is also considered.

A comparison of methods to approximate standard errors for complex survey data.

Complex survey designs are characterized by multistage selections with stratification and clustering. The departure from simple random sampling assumptions requires special consideration with regard to variance estimation. Specially designed software packages exist to generate variance estimates for statistics from complex survey data. The variance estimation techniques used include balanced repeated replication, jackknife, and Taylor series linearization. Many complex surveys generate thousands of tables. The computational and publishing costs soar if estimates of standard error are required for all statistics. To decrease these costs, several alternative techniques to approximate the standard errors of estimates are available. These include the widely used relative variance curve, a method based on the average relative standard error, and the average design effect model. In this paper these three methods are compared with respect to accuracy, computational and publishing costs, and ease of implementation.