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Biomedical subjects

R M Royall

Publications and source records attributed to R M Royall.

7 recordsLinked to original sources
PubMed1991

Racial differences in the cause-specific prevalence of blindness in east Baltimore.

BACKGROUND: Bilateral blindness unrelated to simple refractive error is twice as prevalent among blacks as among whites, although the difference narrows among the elderly. The reasons for this race- and age-related pattern are uncertain. METHODS AND RESULTS: A randomly selected, stratified, multistage cluster sample of 2395 blacks and 2913 whites 40 years of age and older in East Baltimore underwent detailed ophthalmic examinations by a single team. We identified 64 subjects who were blind in both eyes. The leading causes of blindness were unoperated senile cataract (accounting for blindness in 27 of the total of 128 eyes), primary open-angle glaucoma (17 eyes), and age-related macular degeneration (16 eyes). Together, these three disorders accounted for 47 percent of all blindness in this sample. Unoperated cataract accounted for 27 percent of all blindness among blacks, among whom it was four times more common than among whites; whites were almost 50 percent more likely than blacks to have undergone cataract extraction before the age of 80 (P less than 0.002). Primary open-angle glaucoma accounted for 19 percent of all blindness among blacks; it was six times as frequent among blacks as among whites and began 10 years earlier, on average. By contrast, age-related macular degeneration resulting in blindness was limited to whites, among whom it was the leading cause of blindness (prevalence, 2.7 per 1000; 95 percent confidence interval, 1.2 to 5.4); it affected 3 percent of all white subjects 80 years of age or older. CONCLUSIONS: The pattern of blindness in urban Baltimore appears to be different among blacks and whites. Whites are far more likely to have age-related macular degeneration, and blacks to have primary open-angle glaucoma. The high rate of unoperated cataracts among younger blacks and among elderly subjects of both races suggests that health services are underused. Half of all blindness in this urban population is probably preventable or reversible.

Adult↗
PubMed1991

Racial variations in the prevalence of primary open-angle glaucoma. The Baltimore Eye Survey.

OBJECTIVE: --To compare the prevalence of primary open-angle glaucoma between black and white Americans. DESIGN, SETTING, AND PARTICIPANTS: --The design was a population-based prevalence survey of a noninstitutionalized black and white population aged 40 years or older from the eastern and southeastern health districts of Baltimore, Md. A multistage random sampling strategy was used to identify 7104 eligible participants, of whom 5308 (2395 blacks, 2913 whites) received an ophthalmologic screening examination. Those with abnormalities were referred for definitive diagnostic evaluation. MAIN OUTCOME MEASURE: --Primary open-angle glaucoma was defined based on evidence of glaucomatous optic nerve damage, including abnormal visual fields and/or severe optic disc cupping, and was independent of intraocular pressure. MAIN RESULTS: --Age-adjusted prevalence rates for primary open-angle glaucoma were four to five times higher in blacks as compared with whites. Rates among blacks ranged from 1.23% in those aged 40 through 49 years to 11.26% in those 80 years or older, whereas rates for whites ranged from 0.92% to 2.16%, respectively. There was no difference in rates of primary open-angle glaucoma between men and women for either blacks or whites in this population. Based on these data, an estimated 1.6 million persons aged 40 years or older in the United States have primary open-angle glaucoma. CONCLUSIONS: --Black Americans are at higher risk of primary open-angle glaucoma than their white neighbors. This may reflect an underlying genetic susceptibility to this disease and indicates that additional efforts are needed to identify and treat this sight-threatening disorder in high-risk communities.

Adult↗
PubMed1990

Blindness and visual impairment in an American urban population. The Baltimore Eye Survey.

Data on the prevalence of blindness and visual impairment in multiracial urban populations of the United States are not readily available. The Baltimore Eye Survey was designed to address this lack of information and provide estimates of prevalence in age-race subgroups that had not been well studied in the past. A population-based sample of 5300 blacks and whites from east Baltimore, Md, received an ophthalmologic screening examination that included detailed visual acuity measurements. Blacks had, on average, a twofold excess prevalence of blindness and visual impairment than whites, irrespective of definition. Rates rose dramatically with age for all definitions of vision loss, but there was no difference in prevalence by sex. More than 50% of subjects improved their presenting vision after refractive correction, with 7.5% improving three or more lines. Rates in Baltimore are as high or higher than those reported from previous studies. National projections indicate that greater than 3 million persons are visually impaired, 890,000 of whom are bilaterally blind by US definitions.

Adult↗
PubMed1989

Health and mental health problems of homeless men and women in Baltimore.

A study of homeless people in Baltimore, Md, focused on their health and other characteristics, with special emphasis on their needs for services. In the first stage, 298 men and 230 women were randomly selected from the missions, shelters, and jail in Baltimore to respond to a baseline interview that provided extensive sociodemographic and health-related data. In the second stage, a subsample of 203 subjects was randomly selected from the baseline survey respondents to have systematic psychiatric and physical examinations. Data are presented from both stages. Data from the first stage demonstrate, among other things, the high levels of disaffiliation of this population and their heavy involvement in substance abuse. Data from the clinical examinations demonstrate the high prevalence of mental illnesses and other psychiatric disorders and of a wide range of physical disorders and confirm the high prevalence of alcohol abuse disorders. The high rates of comorbidity of these conditions is demonstrated and data are provided on the subjects' needs for mental health and substance abuse services.

Adult↗
PubMed1979

Prediction models in small area estimation.

Finite population estimation problems are formulated as prediction problems under superpopulation models. For linear regression models, a general theorem on optimal linear estimation is presented. The theorem is applied to simple cross-classification models to generate and analyze various statistics for estimating small area totals. These statistics include the synthetic and composite estimators, as well as some interesting alternatives.

Humans↗