Biomedical subjects

D Wentworth

Publications and source records attributed to D Wentworth.

26 records · Page 2Linked to original sources

PubMed1986

Serum cholesterol, blood pressure, and mortality: implications from a cohort of 361,662 men.

The risks associated with various levels of serum cholesterol were determined by analysis of 6-year mortality in 361,662 men aged 35-57. Above the 20th percentile for serum cholesterol (greater than 181 mg/dl, greater than 4.68 mmol/l), coronary heart disease (CHD) mortality increased progressively; the relative risk was large (3.8) in the men with cholesterol levels above the 85th percentile (greater than 253 mg/dl, greater than 6.54 mmol/l). When men below the 20th cholesterol percentile were used as the baseline risk group, half of all CHD deaths were associated with raised serum cholesterol concentrations; half of these excess deaths were in men with cholesterol levels above the 85th percentile. For both CHD and total mortality, serum cholesterol was similar to diastolic blood pressure in the shape of the risk curve and in the size of the high-risk group. This new evidence supports the policy of a moderate fat intake for the general population and intensive treatment for those at high risk. There is a striking analogy between serum cholesterol and blood pressure in the epidemiological basis for identifying a large segment of the population (10-15%) for intensive treatment.

Adult↗

PubMed1986

Prevalence and prognostic significance of hypercholesterolemia in men with hypertension. Prospective data on the primary screenees of the Multiple Risk Factor Intervention Trial.

To assess the impact of serum cholesterol level on the risk of fatal coronary heart disease for men with high blood pressure, the six-year follow-up data from 361,662 men (aged 35 to 57 years) screened in 18 cities in the recruitment effort for the Multiple Risk Factor Intervention Trial were evaluated. Of these men, 356,222 reported no history of hospitalization for myocardial infarction; 100,032 of these 356,222 had a baseline mean diastolic blood pressure equal to or greater than 90 mm Hg. For those men with high blood pressure, the overall age-adjusted six-year rate of coronary heart disease death was 79 percent higher than for those with diastolic blood pressure less than 90 mm Hg. Compared with men with diastolic blood pressure less than 90 mm Hg and serum cholesterol below 182 mg/dl, men with diastolic blood pressure equal to or greater than 90 mm Hg had the following relative risks, based on the serum cholesterol level: for those with a serum cholesterol level less than 182 mg/dl, risk was 1.64; for those with a level of 182 to 202 mg/dl, risk was 2.14; for those with a level of 203 to 220 mg/dl, risk was 3.14; for those with a level of 221 to 244 mg/dl, risk was 3.29; and for those with a level equal to or greater than 245 mg/dl, risk was 5.14. Thus, for men with high blood pressure, serum cholesterol related to coronary heart disease risk in a strong, graded way, over the entire distribution of serum cholesterol, from levels of 182 mg/dl and higher. This was the case for hypertensive male smokers and nonsmokers, with cigarette use associated with a further marked increase in risk--at least a doubling of the mortality rate--at any level of serum cholesterol. These data underscore the necessity for a strategy of comprehensive care for persons with high blood pressure, including approaches to both nutritional and hygienic counseling and drug treatment, aimed at controlling all of the established major risk factors influencing prognosis.

Adult↗

PubMed1986

Overall and coronary heart disease mortality rates in relation to major risk factors in 325,348 men screened for the MRFIT. Multiple Risk Factor Intervention Trial.

The influence of risk factors on CHD and all-cause mortality rates in 35- to 57-year-old men is examined by means of data on 325,348 white men who were screened for the MRFIT. This large data set permits an unusually detailed analysis of factors associated with the 6968 deaths, including 2426 ascribed to CHD, that were detected in the Social Security Administration data set during 6 years of follow-up. Simple cross classification of the data confirms the independent effect of serum cholesterol concentration, diastolic blood pressure, and cigarette smoking as risk factors for CHD and all-cause mortality rates. A distinct escalation of risk is noted for combinations of these risk factors. The strength of the association of each of the risk factors with CHD and all-cause mortality rates diminished with increasing age, although the number of excess deaths attributable to the risk factors increased because of the higher death rates in older men. Comparison of these findings with those observed in the five populations studied in the Pooling Project revealed an overall similarity in the risk relationships. It is estimated that elimination of these risk factors has the potential for reducing the CHD mortality rate by two thirds in 35- to 45-year old men, and by one half in 46- to 57-year-old men.

Adult↗

PubMed1986

Comparability of ophthalmic diagnoses by clinical and Reading Center examiners in the Visual Acuity Impairment Survey Pilot Study.

Technologic advances in ophthalmic equipment offer the possibility of replacing direct clinical examinations with Reading Center evaluations of data recorded in epidemiologic studies. Clinical and Reading Center examiners made independent ophthalmic diagnoses of 133 right and 132 left eyes of 138 adults in the Visual Acuity Impairment Survey Pilot Study, carried out in three US cities, Boston, Detroit, and Minneapolis, in August 1981-December 1982. The Reading Center diagnosed eye conditions using only photographic and visual field data collected at the time of the clinical examination. In the comparisons of clinical and Reading Center evaluations reported here, only eyes judged by the examiners to have pathology severe enough to reduce visual acuity to 6/9 or worse were classified as having pathology. (No visual acuity criterion was required for the diagnosis of glaucoma or diabetic retinopathy.) There was agreement in diagnostic assessments between clinical and Reading Center examiners in about 80% of eyes. The kappa statistic, which adjusts for chance agreement, was in the fair to good range: 0.60 for 133 right eyes and 0.62 for 132 left eyes. When the Reading Center examiners were provided with additional information on medical history, refractive error and best corrected visual acuity, the agreement between clinical and Reading Center assessments among the subset of eyes with 6/9 or worse vision again was in the fair to good range, with kappas of 0.61 for 45 right eyes and 0.68 for 48 left eyes. Inter-observer agreement between Reading Center examiners in diagnosing pathology was in the good to excellent range. Use of Reading Centers in future epidemiologic studies should be considered, but elimination of the clinical examinations is not recommended until modifications in the protocol described here have been made and shown to improve levels of agreement between clinical and Reading Center examiners.

Eye Diseases↗

PubMed1986

Lessons from the Visual Acuity Impairment Survey pilot study.

The Visual Acuity Impairment Survey (VAIS) pilot study was carried out in three large metropolitan areas of the United States to determine whether it would be feasible to conduct a large two-stage survey of the prevalence of visual acuity impairment and its causes. The study was conducted in conjunction with the Health Interview Survey (HIS), performed by the National Center for Health Statistics and the Census Bureau. In the first stage, a simple vision screening test was administered to 1,868 adults in their homes by specially trained Census Bureau interviewers. All those who failed the test, and a sample of those who passed it, were invited to a local clinic for a check on the accuracy of the screen and a detailed eye examination to establish the cause of the impairment. About 89 per cent of the HIS interviewees took the vision screening test in the home and agreed to have the results released, making it possible for the clinic to invite them for an examination. The principal obstacle to the success of the feasibility study was a low rate (less than 50 per cent) of participation in the clinic examination by the target population. Such low participation would leave the survey open to a serious question about its representativeness. The methods and findings of the pilot study are presented because the lessons may be of value to those attempting similar studies in the future. Suggestions are made for methodological modifications that may enhance the chances for success.

Adult↗

PubMed1984

Total and cardiovascular mortality in relation to cigarette smoking, serum cholesterol concentration, and diastolic blood pressure among black and white males followed up for five years.

The Multiple Risk Factor Intervention Trial screening program provided an opportunity (1) to study the association of diastolic blood pressure level, serum cholesterol concentration, and cigarettes per day with all-cause and cause-specific mortality after 5 years among 23,490 black males and (2) to compare these associations with those observed among 325,384 white males. The relationship of serum cholesterol concentration and reported cigarettes per day to all-cause, coronary heart disease (CHD), and cerebrovascular disease mortality was similar for black and white males. Diastolic blood pressure was more positively associated with cerebrovascular disease death among black males than white males (p = 0.047) according to logistic regression analysis. The lower CHD mortality among black males compared to white males was most apparent among hypertensive males (diastolic blood pressure greater than or equal to 90 mm Hg). The relative risk (black vs white) of CHD death adjusted for age, serum cholesterol concentration, and cigarettes per day was 0.69 for hypertensive males compared to 1.15 for nonhypertensive males (p = 0.012 for difference in relative risk estimates). These findings suggest that the causes of CHD and cerebrovascular disease may be different for black and white males, particularly in regard to how these disease processes relate to blood pressure.

Adult↗

PubMedDate not supplied

An examination of the efficiency of some quality assurance methods commonly employed in clinical trials.

The cost and efficiency of training clinical centre staff and of duplicate data entry in clinical trials is reviewed. Training is an essential component of quality assurance programmes and it is usually carried out at regular intervals in long-term clinical trials. Initial training of staff and regular retraining is important to assure standardization and it can lead to reduced trial costs. Interim training for new staff and for remedial purposes is less efficient than regularly scheduled training sessions. Regional centres for training and the use of computer aided instruction are two ways such interim training can be made more efficient and standardized. Duplicate data entry or verification can result in a substantial reduction in data entry errors depending on the nature of the data being keyed. Selective verification should especially be considered for important fields for which consistency checks cannot be performed, that are alphabetic or that are several characters in length. Quality assurance procedures should be implemented to monitor data entry accuracy in clinical trials.

Documentation↗

PubMedDate not supplied

Predictors of prism response during prism adaptation. Prism Adaptation Study Research Group.

Results of the Prism Adaptation Study (PAS) indicate that prism adaptation improves the success rate of strabismus surgery for patients with acquired esotropia. Patients who show a fusion response to the prisms benefit most from this preoperative treatment. This study analyzes the characteristics of those patients who were and were not prism responders in the PAS. Significant factors predicting a prism response included: patients who were older at the time of onset of their esodeviation (P = .007), duration of deviation less than 1 year (P = .04), alternating fixation (P = .003), fusion on the Worth four-dot test at near with prism neutralization (P = .008), and equal vision (P = .009). Demographic characteristics were similar for both responders and nonresponders except that non-Hispanic patients were significantly more likely to respond to prisms than Hispanic patients (P less than .002). No test or characteristic was found which could reliably predict the prism response. Therefore, all patients with acquired esodeviations should be considered candidates for prism adaptation prior to strabismus surgery.

Adaptation, Ocular↗