Biomedical subjects

B M Psaty

Publications and source records attributed to B M Psaty.

At least 19 recordsLinked to original sources

PubMed1992

Isolated systolic hypertension and subclinical cardiovascular disease in the elderly. Initial findings from the Cardiovascular Health Study.

OBJECTIVE: To assess the association between isolated systolic hypertension (ISH) and subclinical disease in adults aged 65 years and above. DESIGN: Medicare eligibility lists were used to obtain a representative sample of 5201 community-dwelling elderly persons for the Cardiovascular Health Study, a National Heart, Lung, and Blood Institute--sponsored cohort study of risk factors for coronary heart disease and stroke. In this cross-sectional analysis of baseline data, we excluded 3012 participants who were receiving antihypertensive medications, had clinical cardiovascular disease, or had a diastolic blood pressure of at least 90 mm Hg. MAIN OUTCOME MEASURES: For electrocardiogram: myocardial infarction, left ventricular hypertrophy, and left ventricular mass as measures of myocardial damage and strain; for echocardiography: left ventricular mass, fractional shortening, and Doppler flow velocities as measures of cardiac systolic and diastolic function; and for carotid sonography: carotid arterial intima-media thickness as a measure of atherosclerosis. RESULTS: Among the 2189 men and women in this analysis, 195 (9%) had ISH (systolic blood pressure, greater than or equal to 160 mm Hg) and 596 (23%) had borderline ISH (systolic blood pressure, 140 to 159 mm Hg). Systolic blood pressure was associated with myocardial infarction by electrocardiogram (P = .02). Borderline and definite ISH were strongly associated with left ventricular mass (P less than .001). While there was little association with cardiac systolic function, borderline and definite ISH were associated with cardiac diastolic function (P less than .001). Isolated systolic hypertension was also strongly associated with increased intima-media thickness of the carotid artery (P less than .001). CONCLUSIONS: While cohort analyses of future repeated measures will provide a better assessment of risk, both borderline and definite ISH were strongly related to a variety of measures of subclinical disease in elderly men and women.

Aged↗

PubMed1992

Assessing response bias in random-digit dialling surveys: the telephone-prefix method.

Knowledge of the characteristics of survey non-respondents is important to determine generalizability to the population of interest. In a recent random-digit dialling survey of health behaviours only 73 per cent of the households contacted provided any information about household composition, and only 74 per cent of those actually completed the extended interview, for an overall response rate of 54 per cent. To identify possible biases we grouped all attempted phone numbers by their prefix, and looked for the association between the response rate for that prefix and other summary variables known about the prefix. A simulation study showed that the method can identify non-response biases if certain assumptions are correct. The analysis suggested that our survey data under-represent older people and those with a college education. We found no significant biases in health behaviours, possibly because the basic assumptions did not hold. This method may assist in identification of non-response bias in other studies.

Adult↗

PubMed1992

Major electrocardiographic abnormalities in persons aged 65 years and older (the Cardiovascular Health Study). Cardiovascular Health Study Collaborative Research Group.

Electrocardiographic abnormalities are often found in older patients, but their prevalence in free-living elderly populations is not well-defined. In addition, the clinical significance of many of these abnormalities is uncertain. The prevalence of major electrocardiographic abnormalities was determined in 5,150 adults aged greater than or equal to 65 years from the Cardiovascular Health Study--a study of risk factors for stroke and coronary heart disease in the elderly. Ventricular conduction defects, major Q/QS waves, left ventricular hypertrophy, isolated major ST-T-wave abnormalities, atrial fibrillation and first-degree atrioventricular block were collectively categorized as major electrocardiographic abnormalities. Prevalence of any major electrocardiographic abnormality was 29% in the entire cohort, 19% among 2,413 participants who reported no history of coronary artery disease or systemic hypertension, and 37% among 2,737 participants with a history of coronary artery disease or hypertension. Prevalence of major electrocardiographic abnormalities was higher in men than in women regardless of history, and tended to increase with age. Major Q/QS waves were found in 5.2%, and more than half were in those who did not report a previous myocardial infarction. Major electrocardiographic abnormalities are common in elderly men and women irrespective of the history of heart disease.

Age Factors↗

PubMed1992

Sodium and blood pressure: the puzzling results of intrapopulation epidemiologic studies.

Most intrapopulation epidemiologic studies have been unable to find a significant association between sodium intake and blood pressure. The researchers have offered 2 opposing explanations: the hypothesis of the genetic susceptibility to sodium and the hypothesis of a weak association in general population. The evidence for and against each hypothesis is reviewed. The direction of future research is suggested.

Animals↗

PubMed1992

Assessing the use of medications in the elderly: methods and initial experience in the Cardiovascular Health Study. The Cardiovascular Health Study Collaborative Research Group.

The Cardiovascular Health Study (CHS), a cohort study of risk factors for coronary heart disease and stroke, recruited 5201 community-dwelling adults aged 65 years or older. To assess the prevalence of medication use at baseline, we used the method of medication inventory and transcribed information about drug names and doses from prescription bottles. Using a specially-written computer program, persons without a knowledge of drug nomenclature coded 10,511 (89%) of the 11,846 medicines entered. We compared the results of the medication inventory and answers to questions on specific medications for reliability and validity. The use of beta-blockers and beta-agonists assessed by the method of medication inventory, but not by the method of directed recall, was associated with a significant effect on mean heart rate. Among 5197 participants with medication data, 76.1% were taking at least one medicine, and the mean number of drugs per person was 2.28. Among those with a reported history of high blood pressure, participants with cardiovascular disease (CVD) were more likely to be treated, and they were more likely to be taking beta-blockers and calcium-channel blockers than those without CVD. Daily aspirin use was also more common among those with CVD (30.5% of women and 43.2% of men) than among those without CVD (14.0% of women and 14.0% of men). The prevalence of post-menopausal estrogen use differed significantly among the four clinical centers (range = 5.5%-22.5% of women). We conclude that this method of assessing medications was easy to use and provided estimates of exposure to drugs that may affect risk of cardiovascular disease.

Aged↗

PubMed1992

The distribution of coagulation factors VII and VIII and fibrinogen in adults over 65 years. Results from the Cardiovascular Health Study.

The Cardiovascular Health Study (CHS) was designed to examine cardiovascular disease and its risk factors in older adults. We report here the distributions of the coagulation factors fibrinogen, factor VII, and factor VIII in a population-based cohort of men and women 65 years or older. In other studies of middle-aged individuals, these factors were shown to be associated with cardiovascular risk. In the CHS cohort, all three factors were elevated, compared to levels reported in middle-aged individuals, and fibrinogen and factor VIII values were higher in each successive age group; factor VII values, in contrast, declined slightly with age in the CHS cohort. Compared to white subjects, blacks had higher values for fibrinogen and factor VIII and lower values for factor VII. While women had markedly higher values for factor VII and factor VIII than men at all ages in the CHS, mean fibrinogen values were not different between men and women.

Age Factors↗

PubMed1992

Level of blood pressure and risk of myocardial infarction among treated hypertensive patients.

To examine the association between the level of treated blood pressure and the incidence of myocardial infarction, we conducted a population-based case-control study of 912 members of a health maintenance organization who were receiving standard clinical treatment for hypertension. We found a J-shaped relationship between the most recently measured diastolic blood pressure and the risk of myocardial infarction, the lowest risk occurring at 84 mm Hg. The relative risk of myocardial infarction at 60 mm Hg was 2.07 (95% confidence interval, 0.86 to 5.01), and at 100 mm Hg, 1.45 (95% confidence interval, 1.02 to 2.06). Treated systolic pressure bore a linear relationship to the risk of infarction. We conclude that the optimum target range for diastolic blood pressure in hypertensive patients may be 84 to 90 mm Hg. Levels outside this range may be associated with increased risk of myocardial infarction.

Adrenergic beta-Antagonists↗

PubMed1992

Medical care and cost outcomes after pentoxifylline treatment for peripheral arterial disease.

We assessed the medical outcomes and costs associated with the pharmacologic treatment of patients with peripheral arterial disease (PAD) in a population-based historical cohort study of patients enrolled in a health maintenance organization. For up to 2 years, we compared 58 patients who used therapeutic amounts of pentoxifylline with a comparison group of 112 patients who received a minimal subefficacious trial of pentoxifylline. Medical records data were used to assess and control for the severity of PAD and other potentially confounding factors. Continuous use of a therapeutic amount of pentoxifylline during an initial 120-day period significantly reduced the incidence of PAD-related invasive therapeutic and diagnostic procedures in the first year of follow-up (adjusted relative risk, 0.35; 95% confidence interval, 0.12 to 0.99). However, there were no significant differences in the risk of a PAD-related hospitalization or cost of PAD-related care between continuous pentoxifylline users and the comparison group. Pentoxifylline therapy may reduce the risk of vascular surgery while not increasing the total cost of PAD care.

Aged↗

PubMed1991

Sampling elderly in the community: a comparison of commercial telemarketing lists and random digit dialing techniques for assessing health behaviors and health status.

A study of health behaviors in four communities in the western United States in 1988 provided the opportunity to compare two methods of sampling elderly respondents for a telephone interview. The Polk telemarketing lists were used to identify 1,407 respondents aged 65 years and older in four communities, where 253 respondents in the same age group were also identified by the method of random digit dialing. Individuals identified from the Polk lists received a letter prior to the initial telephone contact. The overall response rate was 49.3% for random digit dialing and 57.3% for the Polk lists. On the average, the identification of one elderly respondent using the Polk lists required about 20-25% as much interviewer time per subject identified as was required by the random digit dialing method. The elderly identified by the Polk lists were significantly older than those identified by random digit dialing, and the proportions of the Polk sample who were married, white, or had an income of greater than $10,000 were slightly higher than those of the random digit dialing sample. Among 40 variables measuring various health behaviors, indicators of health status, and participation in health-related programs and classes, only three differed significantly between the two samples. The authors conclude that sampling from commercial telemarketing lists was an efficient method of identifying elderly respondents and that in these four communities, the estimates of health behaviors and health status were comparable with those obtained by random digit dialing techniques.

Aged↗

PubMed1991

An approach to several problems in using large databases for population-based case-control studies of the therapeutic efficacy and safety of anti-hypertensive medicines.

In this paper we discuss approaches to two distinct problems in using large computerized databases to conduct population-based case-control studies. The first topic, concerning case ascertainment, is a methodologic problem, and the second, concerning confounding by indication, is an analytic problem. The first involves attempting to ascertain all incident cases of coronary disease among enrollees of Group Health Cooperative of Puget Sound (GHC), a large health-maintenance organization. Methodologic studies reported here have helped us improve the efficiency of using the large computerized databases for case ascertainment at GHC. The second problem involves the issue of confounding by drug indication. Drugs such as beta-blockers have multiple indications, including the treatment of both high blood pressure and angina. These two indications may make it difficult in an observational study to determine whether beta-blockers may prevent coronary disease in patients with high blood pressure. We discuss here our current thinking about the best analytic approach to this problem.

Adrenergic beta-Antagonists↗

PubMed1991

The place of human values in the language of science: Kuhn, Saussure, and structuralism.

The current paradigm in medicine generally distinguishes between genetic and environmental causes of disease. Although the word "paradigm" has become a commonplace, the theories of Thomas Kuhn have not received much attention in the journals of medicine. Kuhn's structuralist method differs radically from the daily activities of the scientific method itself. Using linguistic theory, this essay offers a structuralist reading of Thomas Kuhn's The Structure of Scientific Revolutions. Our purpose is to highlight the similarities between these structuralist models of science and language. In part, we focus on the logic that enables Kuhn to assert the priority of perception over interpretation in the history of science. To illustrate some of these issues, we refer to the distinction between environmental and genetic causes of disease. While the activity of scientific research results in the revision of concepts in science, the production of significant differences that shape our knowledge is in part a social and linguistic process.

Disease↗

PubMed1991

Community-level comparisons between the grocery store environment and individual dietary practices.

BACKGROUND: This article examines the relationship at the community level between individual dietary practice and the grocery store environment. METHODS: Individual dietary practice was measured in 12 communities using a telephone survey to obtain self-reported diet. A protocol was developed to measure two aspects of the grocery store environment in these same 12 communities: the relative availability of healthful (low-fat and high-fiber) products, and the amount of health-education information provided. Comparisons were made between individual and store-level measures at two levels of geographic aggregation: community (typically a county) and zip code within community (n = 34). RESULTS: We found positive and statistically significant correlations at both the community and the zip code level between the availability of healthful products in stores and the reported healthfulness of individual diets. Positive correlations were also found between measures of the amount of health-education material provided by stores and the healthfulness of individual diets, but these correlations did not reach statistical significance. CONCLUSIONS: The results provide support for including measures of the grocery store environment as part of a community-level assessment of dietary behavior.

Adult↗

PubMed1991

The evaluation of the Henry J. Kaiser Family Foundation's Community Health Promotion Grant Program: design.

The Kaiser Family Foundation's Community Health Promotion Grant Program (CHPGP) provides funding and technical assistance in support of community-based efforts to prevent major health problems. The first phase of the program was implemented in 11 communities in the western United States. This paper describes the evaluation design of the CHPGP in the West, the methods of data collection, and the baseline comparability of intervention and control communities. Major features of the evaluation design include: (1) the randomization of qualified communities making application into funded and unfunded comparison groups; (2) a second set of matched control communities for some intervention sites; (3) data gathering through repeated surveys of community residents (probability samples of adults and adolescents) and institutions (health-related organizations and randomly sampled grocery stores and restaurants); and (4) the use of secondary data to monitor health events. Selected baseline data show that intervention and control communities differ in racial/ethnic composition, but relevant health behaviors and ratings of community activation for health promotion appear comparable.

Adolescent↗

PubMed1991

Data analysis and sample size issues in evaluations of community-based health promotion and disease prevention programs: a mixed-model analysis of variance approach.

The growing interest in community-based approaches to health promotion and disease prevention (HP/DP) has been accompanied by a growing need to evaluate the effectiveness of such programs. Special issues that arise in these evaluation studies include (1) entire communities are assigned to intervention and control groups, (2) only a small number of communities can usually be studied, (3) the time course of changes in behavior and other outcomes is often of interest, and (4) surveys to measure such changes over time can be conducted with either repeated cross-sectional samples or with longitudinal samples. This paper shows how these issues can be addressed under a mixed-model analysis of variance approach. This approach serves to unify several ideas in the literature on evaluation of community studies, including use of time-series regression and the question of whether the individual or the community should be the unit of analysis. We also describe how the method can be used to estimate sample size requirements, statistical power, or minimum detectable program effect.

Analysis of Variance↗

PubMed1991

Use of sonography to evaluate carotid atherosclerosis in the elderly. The Cardiovascular Health Study. CHS Collaborative Research Group.

Carotid sonography is being performed on more than 5,000 participants in the Cardiovascular Health Study, a prospective, multicenter study of cardiovascular disease in men and women aged 65 years and older. The sonographic methods used to examine and measure the extracranial carotid arteries are described. Initial validation studies were performed on 61 subjects with a mean age of 68.6 years. Analysis of within- and between-sonographer differences and between-reader differences were performed for selected variables. In general, the mean absolute differences for within- and between-sonographer comparisons were small, with even less variability between readers. Variability was less for the common carotid artery than for the internal carotid artery. These data suggest that carotid sonography is a reliable and reproducible method for use in the study of carotid atherosclerosis in population studies.

Age Factors↗

PubMed1991

Alcohol counseling in a general medicine clinic. A randomized controlled trial of strategies to improve referral and show rates.

We conducted a controlled trial of two interventions to increase the number of patients receiving alcohol counseling in an academic, general medicine clinic. Ongoing randomization yielded similar groups of patients and providers. By applying a two-item alcoholism-screening instrument incorporated into the routine intake process, nursing staff were successful in screening 90.4% of the 1,328 eligible patients seen during a 4-month study period. Of the patients screened, 428 (35.6%) were found to be positive. In those groups where nurses were allowed to refer directly on the basis of a positive screening result, over four times as many patients (10.8% versus. 2.3%) accepted appointments for counseling, as did patients seen by physicians providing standard care. Patients who were briefly introduced to the alcohol counselor at the time referral were no more likely to keep their first, formal appointments than were patients scheduled in the usual manner. Patients who did receive counseling had their diagnoses confirmed by the 25-item Michigan Alcoholism Screening Test. We conclude that the adoption of an alcohol screening program in our clinic increased the number of patients appropriately referred for counseling.

Alcoholism↗

PubMed1990

Beta blockers and the primary prevention of nonfatal myocardial infarction in patients with high blood pressure.

A population-based, case-control study was conducted to determine whether beta blockers, used for the treatment of high blood pressure, prevent first events of coronary heart disease. All study subjects were health-maintenance organization enrollees with pharmacologically treated hypertension. Patients presented in 1982 to 1984 with new coronary heart disease, and control subjects were a probability sample of eligible hypertensive enrollees free of coronary heart disease. With the investigators blind to case-control status, the subjects' medical records were reviewed for other coronary risk factors, and the health-maintenance organization's computerized pharmacy database was used to ascertain the use of beta blockers. A larger proportion of controls than cases were using beta blockers. This difference was confined to the subgroup with nonfatal myocardial infarctions. For current use, the estimated relative risk for nonfatal myocardial infarction was 0.62 (95% confidence interval, 0.39 to 0.99). Among current users of beta blockers, higher doses conferred greater protection. Past use and total lifetime intake of beta blockers were only weakly associated with case-control status. The current use of beta blockers may prevent first events of nonfatal myocardial infarction in patients with high blood pressure.

Adrenergic beta-Antagonists↗

PubMed1990

Risk ratios and risk differences in estimating the effect of risk factors for cardiovascular disease in the elderly.

This article reviews the nature of the effects of hypertension, smoking and cholesterol on the incidence of cardiovascular disease and emphasizes how these effects vary by age. In the Methods section, we discuss briefly the concepts of additive and multiplicative statistical models as tools for summarizing data. In the results section, we summarize available data on the association between incident stroke and coronary heart disease in the elderly and each of these major risk factors. The traditional multiplicative model parsimoniously characterizes the individual and joint effects of age and high blood pressure in terms of risk ratios; but, for smoking and cholesterol, an additive model appears to be the most parsimonious. We discuss the consequences of these observations for the study and prevention of cardiovascular disease in the elderly.

Adult↗