Denis A. Evans

Use of brief cognitive tests to identify individuals in the community with clinically diagnosed Alzheimer's disease.

Two brief screening tests, the Short Portable Mental Status Questionnaire (SPMSQ) and the East Boston Memory Test (EBMT), were included in a population questionnaire administered to 3,811 persons 65 years of age and older. A detailed clinical evaluation was then administered to 467 persons (drawn from high, medium and low performers on the EBMT) to determine who was cognitively impaired and the disorders that were responsible for that cognitive impairment. The results showed that the EBMT was better at enriching the population of the poor performance group with persons who had Alzheimers disease (AD). It had a lower refusal rate among non-proxy respondents: 2% for the EMBT versus 9% for the SPMSQ. The sensitivity and positive predictive value were also higher for the EBMT than the SPMSQ when the diagnosis of interest was AD. However, there were persons with AD in all strata of performance on both the EBMT and the SPMSQ, emphasizing the importance of selecting persons from all performance strata in multistage community studies of AD.

Established populations for epidemiologic studies of the elderly: Study design and methodology

A project initiated by the intramural Epidemiology, Demography and Biometry Program of the National Institute on Aging, entitled “Established Populations for Epidemiologic Studies of the Elderly” (EPESE), has developed information on death, chronic conditions, disabilities, and institutionalization for representative samples of elderly people living in communities. The EPESE consists of prospective epidemiologic studies of approximately 14 000 persons 65 years of age and older in four different communities: East Boston, Massachusetts; two rural counties in Iowa; New Haven, Connecticut; and segments of five counties in the north-central Piedmont area of North Carolina. The study design includes an initial baseline household interview followed by continued surveillance of morbidity and mortality. Participants are re-contacted annually in conjunction with the collection of data on cause of death and factors related to hospitalization and nursing home admissions. Concurrently, the investigators developed substudies focused on specific problems of the elderly. The value of this research lies in the longitudinal design which allows for analyses aimed at identifying risk factors of diseases, disabilities, hospitalizations, institutionalization, and mortality. (Aging Clin. Exp. Res. 5: 27–37, 1993)

Short-Term Variability of Measures of Physical Function in Older People

Self reported physical function was assessed in telephone interviews approximately 3 weeks apart for a sample of 193 persons aged 69 or older. Three measures of physical function were used: a modified Activities of Daily Living scale, three items proposed by Rosow and Breslau, and five items from among those used by Nagi. Agreement between first and second interviews was very good; most subjects reported no impairment in function at either interview. Among those who reported some impairment, the degree of limitation within the specific activities reported as limited and the total number of activities with any degree of limitation agreed exactly for most and within one level for almost all subjects. There was no evidence to suggest that age or cognitive impairment affected the variability of the responses, and reported declines and improvements in function were about equally common.

Combinations of Potassium, Calcium, and Magnesium Supplements in Hypertension

Dietary intakes of potassium, calcium, and magnesium have each been reported to lower blood pressure, but the extent of blood pressure reduction in epidemiological studies and clinical trials has tended to be small and inconsistent. We hypothesized that combinations of these mineral supplements would lower blood pressure and that the reductions would be greater than that usually reported in studies of each cation alone. One hundred twenty-five patients 82 men and 43 women) with untreated mild or borderline hypertension were randomly assigned to daily treatment with one of the following four regimens: 60 mmol potassium and 25 mmol (1000 mg) calcium, 60 mmol potassium and 15 mmol (360 mg) magnesium, calcium and magnesium, or placebo. Standardized clinic blood pressure measurements were obtained on 3 days at baseline and after 3 and 6 months of treatment. At baseline, systolic and diastolic blood pressures (mean +/- SD) were 139 +/- 12 and 90 +/- 4 mm Hg, respectively, and dietary intakes of potassium, calcium, and magnesium were 77 +/- 32, 19 +/- 13, and 12 +/- 52 mmol/d, respectively. The mean differences (with 95% confidence intervals) of the changes in systolic and diastolic blood pressures between the treatment and placebo groups were not significant: -0.7 (-4.3 to +2.9) and -0.4 (-2.9 to +2.1) for potassium and calcium, -1.3 (-4.4 to +1.8) and 0.4 (-2.5 to +3.3) for potassium and magnesium, and +2.1 (-1.8 to +6.0) and +2.2 (-1.0 to +5.4) for calcium and magnesium. In conclusion, this trial provides little evidence of an important role of combinations of cation supplements in the treatment of mild or borderline hypertension.

Progression and Resolution of Delirium in Elderly Patients Hospitalized for Acute Care

The authors describe the clinical course of delirium in 325 elderly patients hospitalized for acute care. Of those patients who developed DSM-III delirium (n = 91), over two-thirds of patients (69.2%) experienced a prodromal period of at least 1 day prior to meeting full DSM-III criteria. Clinical evidence of delirium frequently persisted after hospital discharge although there was evidence of lessening of the extent of symptoms over time. These findings have implications for discharge planners concerned with providing appropriate supports for those still experiencing delirium symptoms at the time of hospital discharge.

Population prevalence estimates from complex samples

Epidemiologic studies are often designed to severe several purposes. The complex sampling plans necessary to ensure an adequate number of cases, a similar age distribution among cases and controls, or other important design constraints for comparative studies may make the additional goal of estimating prevalence in the population or in important subgroups difficult to attain with existing computer software, which typically assumes simple random sample selection. We consider here various methods for estimating overall and subgroup prevalence from complex samples, including crude prevalences, direct standardization of prevalences, and standardization using logistic regression to smooth the sampling group prevalences. We illustrate these methods using a complex sample to estimate the prevalence of Alzheimers disease in an urban community. A simulation study under various models in this setting is also described. We conclude that the use of logistic regression to smooth sampling group prevalences before standardization is an effective method for estimation of overall prevalence, provided that the adequacy of fit of a logistic model is carefully checked.

Role of Striated and Smooth Muscle Components in the Urethral Pressure Profile in Traumatic Neurogenic Bladders: A Neuropharmacological and Urodynamic Study. Preliminary Report

Urodynamic investigations with urethral pressure profile, and vesical, intrarectal and anal pressure recordings were performed in 37 patients with spinal cord lesions. The recordings were done before and after phentolamine injections and/or pudendal nerve blocks to evaluate the respective contribution of sympathetic and somatic innervation to the maximum urethral closure pressure in the mid and distal portions of the membranous urethra. A pressure gradient was demonstrated in the membranous urethra with higher values in the distal than in the mid portion. These results emphasize that the interrupted withdrawal technique is superior to the continuous technique in patients with upper motor neuron bladders. Mid urethral striated and smooth muscle components were shown to represent approximately 60 and 30 per cent of the maximum urethral closure pressure, respectively. In the distal urethra striated and smooth components are more abundant than in the mid portion and contribute in equal proportion to the maximum urethral closure pressure. No substantial role was found for the vascular bed in the maximum urethral closure pressure. The greatest pressure decrease in the mid and distal urethra of patients with lower motor neuron bladders was believed to be an effect of denervation supersensitivity. The results of pudendal blocks showed sphincter dyssynergia to be mediated through pudendal nerves via spinal reflex arcs. Phentolamine effects on bladder activity suggest that blockade of alpha-adrenergic receptors inhibits primarily the transmission in vesical and/or pelvic parasympathetic ganglia and acts secondarily through direct depression of the vesical smooth muscle. Our neuropharmacological results raise strong doubts as to the existence of a sympathetic innervation of the striated urethral muscle in humans.

The respective contribution of smooth and striated components in the urethral pressure profile of the spinal cord injured. a neuropharmacological and urodynamic study

The respective contribution of smooth and striated components in the urethral pressure profile of the spinal cord injured. a neuropharmacological and urodynamic study