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Biomedical subjects

J L Fozard

Publications and source records attributed to J L Fozard.

At least 19 recordsLinked to original sources
PubMed1992

Estimation of prostatic growth using serial prostate-specific antigen measurements in men with and without prostate disease.

Prostate growth curves were estimated from serial prostate-specific antigen (PSA) measurements on frozen sera in three groups of men: (a) 16 men with no prostatic disease by urological history and examination; (b) 20 men with a histological diagnosis of benign prostatic hyperplasia (BPH) who had undergone simple prostatectomy; and (c) 18 men with a histological diagnosis of prostate cancer. The median number of repeated PSA measurements over an 8- to 26-yr period prior to histological diagnosis or exclusion of prostate disease was eight and 11 for noncancer and cancer subjects, respectively. Predicted rates of change in PSA (PSA velocity) were linear and curvilinear for control and BPH subjects, respectively. Subjects with cancer demonstrated both a linear and an exponential phase of PSA velocity. Based on time to double PSA, we estimated the epithelial doubling time for men without prostate disease to range from 54 +/- 13 yr at age 40 to 84 +/- 13 yr at age 70. For men with BPH, doubling times ranged from 2 +/- 13 yr at age 40 to 17 +/- 5 yr at age 85. Subjects with local/regional and advanced/metastatic cancer had similar PSA doubling times of 2.4 +/- 0.6 yr and 1.8 +/- 0.2 yr, respectively. These data are consistent with what is known about prostatic growth with age in men without prostate disease and BPH, and the kinetics of prostate cancer growth. Estimates of prostatic growth rate from changes in PSA may be useful clinically in management of men with prostate disease.

Aged↗
PubMed1992

Response stability and reliability in longitudinal health evaluations.

Two approaches were used to study the stability over time and intravisit reliability of health questions and clinical medical examination items in the Baltimore Longitudinal Study of Aging (BLSA). The stability of responses was determined by evaluating the medical history and physical examination completed at each visit to identify items that once answered in a positive manner, should continue to be answered positively over time. Stability for each question and subject was calculated by the number of positive responses following the first positive response divided by the total number of visits following the first positive response. For 35 questions answered by the subject, the stability was 58% by a simple average or 64% when weighted for the percentage of subjects who had a positive response to the question; for 10 physician-asked questions, the corresponding figures were 29% or 36%. Eighteen items from the physical examination had a stability of 34% or 37%. Intravisit reliability was estimated by comparing responses from the general health questionnaire to responses on the Cornell Medical Index completed at the same visit. Subject-completed questions had substantial agreement (Kappa = 0.74, for questions worded the same), while physician-asked questions had moderate agreement (Kappa = 0.44).

Adult↗
PubMed1992

Vision, aging, and driving: the problems of older drivers.

Although there are well-recognized declines in visual functioning with age, their contribution to the problems of older persons on tasks in the natural environment, including driving, are largely unknown. Adults ranging in age from 22-92 years were surveyed in regard to their visual difficulties when driving and performing everyday tasks. The visual problems of drivers increased with age along five different visual dimensions: unexpected vehicles, vehicle speed, dim displays, windshield problems, and sign reading. Several of the age-related visual problems that were reported appear to be related to the types of automobile accidents more common among older drivers. The study also replicated the findings from an earlier investigation of non-driving tasks that showed visual declines with age on five dimensions: visual processing speed, light sensitivity, dynamic vision, near vision and visual search. These findings indicate promising areas of research regarding the effects of visual aging on tasks in the natural environment.

Adult↗
PubMed1992

How comparable are healthy 60- and 80-year-old men?

A critical issue in cross-sectional aging studies is the comparability of subjects of different ages, particularly regarding health status. For example, it is typically assumed that healthy 60-year-old men are equivalent to healthy 80-year-old men when both age groups are selected using the same criteria. The 60-year-old, however, may not survive or be healthy at age 80. To examine this issue, 212 healthy 60-year-old men in the Baltimore Longitudinal Study of Aging were identified. By life table analysis, 30% were expected to survive and remain healthy to age 80. In this study, 61 healthy 60-year-old men were followed to age 80. When compared with 125 healthy 80-year-old men, they had more heart disease, cancer, stroke, arterial, digestive, and peripheral nervous system diseases. Twenty-seven of the 61 men (44%) actually continued to be healthy at age 80. At age 60, systolic pressure and total serum cholesterol were predictive of who would be healthy at age 80.

Age Factors↗
PubMed1991

Effect of age of entry to a longitudinal study on cross-sectional determination of cardiovascular disease.

Cross-sectional analysis from longitudinal studies for a specific age can include subjects who entered the study at different ages (i.e. younger individuals followed to the age of interest, and those who entered at the age of interest). This represents a potential source of bias, since the state of health at a given age may vary based on age at entry. We investigated such bias as it affected the prevalence of cardiovascular diagnoses in men from the Baltimore Longitudinal Study of Aging. Subjects who entered the study in either their 60's, 70's or 80's (New subjects) were compared to individuals who entered the study at an age at least 10 years younger and were followed into these same age decades (Continuing subjects). No differences were found between New and Continuing subjects for coronary heart or cerebrovascular diseases, but were present for hypertension. The greater prevalence of hypertension in Continuing subjects appeared to be of minor clinical importance because other diagnostic differences were absent. The study found evidence for potential selection bias based on age at entry, but the consequence of the bias appeared to be slight.

Age Factors↗
PubMed1990

Symptoms and signs of prostatism as risk factors for prostatectomy.

Symptom questionnaires and physical examinations administered periodically to 1,057 men followed prospectively for up to 30 years in the Baltimore Longitudinal Study of Aging (BLSA) were analyzed to determine which symptoms of prostatism were predictive of subsequent prostatectomy for benign prostatic hyperplasia (BPH). Change in the size and force of the urinary stream (P = 0.0001) and a sensation of incomplete emptying (P = 0.0005) were the only symptoms positively predictive in a multivariate analysis. Prostate enlargement by rectal palpation was an independent risk factor for prostatectomy (P less than 0.03) and was associated with hesitancy (P less than 0.02) and a sensation of incomplete emptying (P less than 0.02). Of the men with all three risk factors, 37% (41/112) eventually had a prostatectomy, in contrast to 8% of the remaining 945 men. This is the first study to document the extent to which urologic symptoms and a digital rectal examination predict subsequent prostatectomy for BPH.

Adolescent↗
PubMed1990

Cumulative prevalence of prostatism matches the autopsy prevalence of benign prostatic hyperplasia.

The age-specific cumulative prevalence of clinically diagnosed prostatism among 1,057 generally healthy men followed for up to 30 years in the Baltimore Longitudinal Study of Aging was compared with the age-specific autopsy prevalence of pathologically defined benign prostatic hyperplasia (BPH) from a published compilation of five independent autopsy studies involving 1,075 prostates. Clinical prevalences based on medical histories and digital rectal examinations showed excellent agreement with autopsy prevalences at all ages. Despite the well-known lack of correspondence between prostatism and objective urologic evidence of BPH in individual patients, these results suggest that the proportion of the male population with clinically recognizable prostatism by a given age is about the same as the proportion with pathological evidence of BPH.

Adult↗
PubMed1990

Next steps in describing aging and disease in longitudinal studies.

Longitudinal studies have contributed much to the understanding of aging. Traditionally, age-specific changes in physiological functioning are inferred from studies in which persons with disease processes believed to be relevant to the function in question are excluded from the results. The main theme of this review is that, in the future, studies of aging must better attempt to capture the interplay between disease and aging processes. A variety of research results, mostly from the Baltimore Longitudinal Study of Aging, are used to support this argument. Topics covered include: the role of longitudinal studies in aging research; the complexity of the aging process; the significance of cohort and secular changes for understanding both aging and disease processes; age changes over the adult life span in the significance of risk factors for disease; and age-related increases in morbidity in a longevous group of men.

Aging↗
PubMed1990

Age changes in pure-tone hearing thresholds in a longitudinal study of normal human aging.

Hearing thresholds were obtained on 813 adult males (20-95 years) measured at 11 frequencies ranging from 0.125-8 kHz from pure-tone audiograms collected over a 20-year period from 1968 to 1987. Audiograms taken at two to six different ages spanning a maximum observation period of 15 years were obtained for each male belonging to one of seven different age groups (20,30,...,80 years) based on the age of initial observation. The males were participants in the Baltimore Longitudinal study of Aging (BLSA), a multidisciplinary community-based study of normal human aging. Changes in hearing thresholds occurred in all age groups during the 15-year follow-up period. For example, at 0.5 and 8 kHz for combined left and right ears there was an average longitudinal loss of 5.7-7.6 and 5.1-21.1 dB, respectively, for 20-year-olds, 10.0-12.7 and 35.2-53.0 dB for 50-year-olds, and 22.9-48.5 and 69.0-84.5 dB for 80-year-olds. As in results from previous cross-sectional studies, hearing loss in the males 70 years and older is greatest at the highest frequencies. The rate of change for these older males is faster in the speech-range frequencies 0.5-2 kHz than in the higher frequencies, since their hearing has already diminished at the high frequencies.

Adult↗
PubMed1990

A longitudinal study of the relationship between intraocular and blood pressures.

The relationship between intraocular and systemic blood pressures was investigated in a prospective study of 572 middle-aged men. There was no consistent relationship between intraocular pressure at first visit and age. Subjects with an intraocular pressure greater than 20 mm Hg had a significantly higher systolic blood pressure than controls matched for age. An autoregressive model was used to examine the relationship between change in intraocular pressure and initial intraocular pressure, age, and blood pressure. When the authors compared data obtained 1 or 2 years apart, a change in intraocular pressure was positively correlated with a change in systolic blood pressure. Thus, the results of this study indicate that changes in intraocular pressure over time are associated with changes in systolic blood pressure and that intraocular pressure does not necessarily increase with age.

Adult↗
PubMed1979

A questionnaire assessment of age differences in retention of recent and remote events.

Age-related differences in memory for recently and remotely dated events have been evaluated through questionnaire assessment. Results from previous studies employing the technique differ in the analysis of retrieval of recent and remote events. In attempting to reconcile extant results from the literature, the following study employed a group of healthy males ranging in age from 26 to 69. The results showed: 1. The elderly exhibited no impairment of the ability to remember recent colloquial events. 2. The elderly's surprisingly accurate recall of remote events was not a product of selective and frequent rehearsal.

Adult↗
PubMed1978

Remembering the person: relations of individual difference variables to memory.

Individual differences in personality and temperament variables were examined in relation to measures of simple mental performance in an attempt to determine the effects of personality on cognitive functioning in the elderly. Shorter latencies in binary decision and choice reaction times, and in recognition memory and object naming tasks were found to be associated with greater trait anxiety and experiential openness. The need to include clinical assessments of memory impairment and measures of more global cognitive abilities and styles in future research on personality and mental performance was discussed, and ways in which information on personality variables might be incorporated into programs of intervention for memory impairment in the elderly were suggested.

Adolescent↗
PubMed1978

Toward applying cognitive skill training to memory problems.

Four elements of a successful program of cognitive skill training for the elderly include: (a) the use of mnemonic aids for the memorization of new information; (b) the development of motivational techniques to enhance attention to materials and maintenance of cognitive skills acquired through training; (c) the design of techniques which utilize individual differences in abilities, personality, and cognitive style to enhance individual programs of cognitive skill training; and (d) the use of appropriate medical and/or psychiatric care when necessary.

Aged↗
PubMed1978

Age and familiarity in memory scanning.

Sixty-five healthy males (31 to 75 years old) memorized lists of six letters (familiar or unfamiliar organization). Letters were then presented singly, and subjects responded yes or no according to whether a given letter was in the memorized set. Subjects of all ages took longer to respond in the case of the unfamiliar list. This was disproportionately true for the oldest subjects, consistent with the idea that the age-related differences in the unfamiliar condition could not be wholly accounted for by psychomotor factors. The distributions of response latencies in the oldest groups had greater variance and skew.

Adult↗
PubMed1978

Speed of retrieval from long-term memory in relation to age, familiarity, and datedness of information.

The time required to name four groups of pictures was measured in 83 community dwelling males (18-70 years of age). One group consisted of objects used 50 to 70 years ago (unique dated exemplars), and another consisted of objects unique to contemporary times (unique contemporary exemplars). For comparison, other pictures of contemporary and dated objects commonly used in both periods were employed. There were three major findings. One, the familiarity of the pictured object is the major determinant of the time required to retrieve its name. Older subjects named the dated unique objects that were relatively more familiar to them more rapidly than did younger adults, while the reverse was true for contemporary unique objects. No age difference in the speed of naming common contemporary objects was found. Two, the overall age-related difference in naming latency was attributed to perceptual-motor aspects of the task. Three, the physical features as well as the familiarity of the object contributed to the speed of retrieval of the object's name.

Adolescent↗
PubMed1978

Retrieval time from different memory stores.

Two experiments were carried out to measure age-related differences in speed of error-free recall by normal adults. The major results were that: (a) the time taken to read a word aloud (retrieval from lexical memory) does not increase appreciably until subjects reach their 60s; (b) the time taken to recall a verbal item just attended to (retrieval from primary memory) increases steadily throughout the adult years, and most markedly between the sixth and seventh decades; and, (c) the time taken to recall recent verbal information outside the span of attention (retrieval from secondary memory) also increases as a function of chronological age, at a relatively rapid rate and most markedly between the fifth and sixth decades. The effects are independent of the number of stimulus-response alternatives.

Adult↗
PubMed1977

Age-related differences in naming latency.

Older people seem to have difficulty learning new materials, perhaps because it takes them longer to retrieve relevant encoding information from memory. To assess the effects of age on speed of retrieval, 60 healthy males from 25 to 74 were shown pictures of common objects they were to name aloud as quickly as possible. The older subjects took longer to name the pictured objects. This difference was minimized with practice or when the name was cued, but did not interact with word frequency. The pattern of results for healthy older subjects was not similar to that found by Wingfield for brain-damaged subjects.

Adult↗