Biomedical subjects
A Looker
Publications and source records attributed to A Looker.
Comparison of two phantoms for body composition with dual-energy X-ray absorptiometry.
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International comparison of hip fracture rates in 1988-89.
A comparison of hip fracture rates among nine countries (Canada, Chile, Finland, Hong Kong, Scotland, Sweden, Switzerland, the United States and Venezuela) was made using national hospital discharge data for the same time interval. The rates increased by age and were higher for females than males in all nine countries. When based on overall discharge rates, the incidence of hip fracture appeared high in three European countries (Finland, Scotland and Sweden) relative to the other countries. However, when transfer cases were removed and adjustments made for differences in case definition, the risk of hip fracture for both men and women was much similar among the four European and two North American countries, but higher than in Hong Kong. Rates of fracture were lowest in Venezuela and Chile, varying from three to 11 times less than for residents of the other seven countries. Although there are limitations in using hospital discharge data as a measure of incidence, the wide variation in the risk of hip fracture across the nine countries appears real but differences between North American and north European countries may not be as great as previously reported. Such cross-national comparisons may help clarify different etiologic hypotheses.
Quality control of bone densitometry in a national health survey (NHANES III) using three mobile examination centers.
A quality control (QC) program for bone mineral measurements at the proximal femur by dual-energy x-ray absorptiometry (DXA) was designed for the osteoporosis component of the Third National Health and Nutrition Examination Survey (NHANES III). Major elements of the QC program are (1) a QC center for review of all scans, (2) setup procedures for and continuous monitoring of daily QC procedures, (3) reference standards for cross-calibration, (4) longitudinal studies for assessment of instrument stability, (5) monitoring of technologist performance, and (6) training. This report describes the results of the QC program of the first half of this 6 year study, which began in 1988. Measurements were performed on 7376 subjects in three mobile examination centers, which traveled to a new location about every 3 months, a total of 44 locations. A small percentage (3.5%) of all scans were rejected, mostly because of patient motion during scanning, but 33% of the remaining scans required reanalysis at the QC center to refine the location of the regions of interest. Precision in spine and hip phantoms was below 1% at all ROIs. In 535 subjects with duplicate scans, age 20-91 of both sexes, examined in a blinded review, precision for BMD at the femur neck ROI was 3.2% (CV) and 5.1% for Ward's triangle BMD. The central review improved scan quality, increased the number of usable scans, and reduced significantly the range of the mean percentage difference in the duplicate scans. Minor alterations in machine function were observed and corrected. QC results on phantoms were similar to those obtained with stationary instruments in dedicated laboratories. Retrospective analysis of the regression slopes from QC records did not show a need for correction of the data base, indicating that the instruments were stable during the course of the study.
Hip fracture rates in Hong Kong and the United States, 1988 through 1989.
OBJECTIVES: Prior studies have suggested that hip fracture rates are substantially lower in Asian countries than in the United States. However, comparisons have been limited by unavailability of recent data, differences in case definition, lack of data from similar time periods, and small sample sizes. This study sought to examine trends by age and sex, with separate statistics for those aged 85 or older. METHODS: Hospital discharge data were used to obtain hip fracture incidence in Hong Kong and the United States from 1988 through 1989. RESULTS: Within each population, women had higher hip fracture rates than men. Fracture rates in the United States were significantly higher for both sexes than rates in Hong Kong. For persons over the age of 80, rates of hip fracture among White US males exceeded those for Hong Kong women. Inclusion of transferred cases in hip fracture rates minimized differences between the countries. CONCLUSIONS: Despite increasing hip fracture rates in Hong Kong, those rates are still substantially lower than the rates in the United States. Identifying factors responsible for this variation may prove useful in the search for preventive strategies.
Vitamin-mineral supplement use: association with dietary intake and iron status of adults.
Although vitamin-mineral supplement use is increasing in the United States, few researchers have examined whether supplement users have better nutritional status than do nonusers. Data from 10,515 persons examined in the second National Health and Nutrition Examination Survey (NHANES II) were used to compare mean dietary intakes of several nutrients and food groups, hemoglobin, mean corpuscular volume, transferrin saturation, erythrocyte protoporphyrin, and serum ferritin between regular supplement users and nonusers aged 16 to 74 years. Prevalences of impaired iron status also were compared between user groups. Users consumed more vitamin C and ate fruits and vegetables more frequently than did nonusers in all age/sex groups. No significant differences in mean iron status indicators were observed except in the 65 to 74 year age/sex groups: transferrin saturation among men and mean corpuscular volume, erythrocyte protoporphyrin, and serum ferritin among women. In each case, users had higher values than nonusers in this age group. Prevalences of impaired iron status did not differ between users and nonusers in any age/sex group. In general, iron status was not associated with supplement use.
Evaluation of two nutrition education modules for hospital staff members.
Two nutrition education modules for inservice training of hospital food service personnel were evaluated in 16 hospitals. The modules, dealing with cardiovascular disease and diet, contained a leader's guide, a teaching package, audiovisual material, and suggested learning activities. Pretests and post-tests were used to assess knowledge gains resulting from learning sessions. Participants were divided so that one group took the post-tests before the sessions and one group after the sessions. When differences between groups were controlled, the sessions were shown to have a significant positive effect on post-test scores. Three-fourths of the participants rated the sessions as "very good" to "excellent."
The influence of the instructor on college multimedia instruction.
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Diphenylhydantoin in children with severe temper tantrums.
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