PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Population Characteristics”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2002

The antisaccade task in a sample of 2,006 young men. I. Normal population characteristics.

A population of 2,075 young men aged 18-25 years selected from the conscripts of the Greek Air Force performed an antisaccade task as part of a prospective study for the identification of risk factors in the development of psychoses. The aim of this study, which is ongoing, is to follow this population and investigate the possible predictive value of oculomotor, cognitive, and psychometric factors for the development of psychosis and other psychiatric conditions. In this report we present data concerning the antisaccade task in this population. We measured performance indices, including the percentage of errors (PE), the latencies of different eye movement responses (latency for correct antisaccades, errors, corrections), and performance in perseveration-prone trials. These indices were also evaluated with respect to IQ (measured by the Raven progressive matrices test) and educational level. Mean PE was 23%, with 17% variance. This large variance is of particular importance whenever the detection of a putative deviant behavior is explored. As mean latency of the first eye movement decreased, the PE increased, as did the latency variance. While the negative correlation between percentage of error and mean latency is well established, the relationship of the latency variability of the first response to error production has not been studied before. Thus, optimal performance appears to require both an intermediate mean latency and a small variability. Furthermore, performance seems to be affected by IQ (the higher the IQ score, the lower the percentage of errors). This report offers an analysis of the interindividual variation in the performance of the antisaccade task and discusses some of the sources of this variation.

Adolescent↗
PubMed2002

Risk assessment at hazardous waste-contaminated sites with variability of population characteristics.

Risk assessment is considered to be an effective scientific tool which enables decisionmakers to manage hazardous waste-contaminated sites in a cost-effective manner while preserving public health. However, the current risk assessment framework proposed by the US Environmental Protection Agency (US EPA) has limitations in addressing the true variability of population characteristics. This study proposed a methodology that is different from the existing framework by accounting for the true variability of population characteristics. The key differences of the proposed methodology and the existing framework are the (1) use of the transient exposure concentration; (2) use of the entire population rather than a representative ideal individual; (3) use of age- and gender-based population subgroups to represent population characteristics; (4) use of a population growth model to represent growth dynamics; and (5) presentation of risk through a risk profile with risk summarized through a single indicator, potential cancer incidences (PCI). The proposed methodology was applied in a ground water contamination scenario due to benzene to determine its applicability. The results of the study showed that age-based variability of population characteristics is important in predicting the population risk while gender played a small role. The existing US EPA methodology and its variation using age-independent variability of population characteristics overestimate the risk given by PCI substantially, and therefore, the decisions can lead to costly cleanup goals. Population risk is not a single value but a distribution due to the contribution from ditferent individuals of the exposed population. Hence, the decision criterion proposed in this study, PCI, is found to be a useful indicator to describe population carcinogenic risk to the society under a variety of conditions and scenarios.

Demography↗
PubMed1992

Selected urban population characteristics of Moscow.

"This paper investigates total and regional population characteristics in Moscow [Russia] during 1979-1989, specifically nationality, age, sex and education and their interrelationships. Population dynamics of Russians, Ukrainians, Jews, and, to a lesser extent, other groups are examined based on a regionalization scheme dividing the city into Inner Zone and Outer Zone [regions]. The same spatial framework is employed in an analysis of changes in the age and sex structures of the city's overall population, as well as in levels of education. Linkages between these characteristics and rates of housing construction, recent demographic history, and city migration policy are explored."

Age Distribution↗
PubMed1987

Population characteristics of the Himalayan region.

"The population of the Himalayan region has tripled between 1901 and 1981 (from 11 to 33 million) and the rate of increase accelerated after about 1951 (from 1.26 to 2.7 percent per annum). These generalized figures, however, conceal significant sub-regional differences. It is argued that aid and development programmes have so far paid insufficient attention to local socio-cultural institutions and environmental conditions, and especially to the status of women." (SUMMARY IN FRE AND GER)

Altitude↗
PubMed2004

[Clonal architecture and ramet population characteristics of Lysimachia congestiflora growing under different light conditions].

The response of clonal architecture and ramet population characteristics to resource heterogeneity is of great ecological significance. This paper studied the variations of clonal architecture and ramet population characteristics of stoloniferous herb Lysimachia congestiflora growing at the open land of forest edge, forest edge, and forest understory of evergreen broad-leaved forest in Mt. Lingyan of Dujiangyan, Sichuan Province, and compared the stolon internode length, frequency distribution of stolon internode length, braching intensity, branching angle, frequency distribution of branching angle, ramet population density, ramet population height, ramet population biomass, and root/shoot of ramet population among the three habitats. The results showed that the stolon internode length, branching intensity, ramet population density and ramet population biomass were different among three habitats. Kruskal Wallis test indicated that the distributions of stolon internode length and branching angle were significantly different among three habitats. The skewness in distribution of stolon internode length was in the order of open land of forest edge>forest edge>forest understory; and the branching angle, ramet population height, and root/shoot of ramet population were significant greater in open land of forest edge than in forest edge and forest understory. The skewness in distribution of branching angle in open land of forest edge was smaller than that in forest edge and forest understory. The branching angle, ramet population height, and root/shoot of ramet population were not significantly different between forest edge and forest understory. These results were discussed in the context of resource acquisition strategy by clonal plants.

Analysis of Variance↗
PubMed2004

Monitoring and evaluating the performance of the UK NHS Cervical Screening Programme: monitoring performance by using cytology outcomes adjusted for population characteristics.

Current quality assurance measures used in the NHS cervical screening programme (NHSCSP) include a review of laboratories with percentages of moderate/severe and borderline/mild smear results outside the 10th-90th percentiles. The method is limited by the fact that many of these outlier smear percentages may reflect laboratories covering populations with low or high risk and/or short or long average screening intervals. This paper outlines a new approach to aid the detection of outlier laboratories, by using data collected at the primary care trust (PCT) or health authority (HA) level and making allowances for population characteristics and screening interval. The setting is the NHSCSP in England using annual data provided by HAs. Data from the screening year 2000-01 is used to illustrate the methodology, although the methods can also be applied to data at the PCT level (now being collected for 2002-03 onwards). Percentages of smear results have been analysed against a series of explanatory variables using logistic regression models. These explanatory variables include Townsend deprivation index, uptake-corrected ethnic minority composition, a measure of screening interval, area type and region. An expected percentage of borderline/mild and moderate/severe smears is estimated from the models and an observed : predicted ratio (OPRmod/sev and OPRbord/mild) calculated. Low values are suggestive of relative undercalling and high values overcalling, after allowance for population characteristics. Analysis of data for 2000-01 showed that the OPRmod/sev for the 99 HAs varied from 0.68 to 1.44. Laboratories with low percentages of moderate/severe smears, but associated with PCTs or HAs with OPRmod/sev values closer to unity may not need to be investigated as their observed rates are consistent with predicted rates based on population characteristics. The method could also be directly applied to laboratories if further information on the population covered by each laboratory were routinely collected.

Female↗
PubMed1996

The effect of changes in population characteristics on breastfeeding trends in fifteen developing countries.

BACKGROUND: Extended breastfeeding is known to benefit the health of children in developing countries and despite widespread expectations of a decline in breastfeeding in these countries, it has been demonstrated that the incidence and duration of breastfeeding are in fact increasing many countries. METHODS: In this paper, trends in breastfeeding duration are examined in 15 developing countries, using data from two comparable surveys for each country, the World Fertility Survey (conducted in the late 1970s) and the Demographic and Health Survey (conducted in the late 1980s). Multivariate regression models are used to examine differentials in breastfeeding behaviour across population subgroups in these countries for each time period, and these differentials are used to determine the extent to which the observed trends are due to changes in population characteristics and to what extent behaviour has changed within population subgroups. RESULTS: Results show that changes in the characteristics of the population have almost universally pushed breastfeeding durations in the downward direction. On the other hand, trends within population subgroups have been positive in all but two of the 15 countries examined. CONCLUSIONS: Changes in population characteristics can be expected to continue for most developing countries, exerting a downward pressure on breastfeeding. Policies that promote breastfeeding are needed to counter these changes, especially in the most vulnerable population subgroups.

Adult↗
PubMed2003

A novel method of estimating cost of therapy by using patient population characteristics: analysis of fluoroquinolones in various populations with different distributions of renal function.

INTRODUCTION: Formulary decisions regarding a given drug class are often made in the absence of patient outcome and/or sophisticated pharmacoeconomic data. Analyses that consider factors beyond simple acquisition costs may be useful in such situations. For example, the cost implications of using manufacturers' recommendations for dosing in patients with renal dysfunction may be important, depending on the distribution of various levels of renal function within a patient population. METHODS: Using four 1000-patient populations representing different renal function distributions and a fifth population of our medical center's distribution, we determined the costs of therapy for intravenous and oral levofloxacin, gatifloxacin, and moxifloxacin for a 10-day course of therapy for community-acquired pneumonia. Costs considered were average wholesale prices (AWPs), 50% of AWP, or same daily price, plus intravenous dose preparation and administration costs when applicable. Costs for each renal function distribution were examined for significant differences with an analysis-of-variance test. Also, costs of failing to adjust dosing regimens for decreased renal function were determined. RESULTS: Differences in fluoroquinolone costs (AWP, 50% AWP, or when matched as the same daily price) among the populations were found. When considering same daily prices, differences among populations ranged from about 35,000 dollars with intravenous gatifloxacin to more than 51,000 dollars for intravenous levofloxacin (all fluoroquinolones, p>0.05). Within a population, differences in costs among the intravenous fluoroquinolones ranged from 47,000-99,000 dollars. Rank orders of the drugs and population costs of therapy were affected by the pricing structure used and varied by the specific population and drug. Differences among the fluoroquinolones or populations were much smaller (<2100 dollars) when considering oral regimens. Costs potentially incurred by failing to adjust dosing for renal function were substantial. CONCLUSION: Formulary decisions can be facilitated by considering factors such as patient characteristics and related dosing in addition to simple acquisition costs. In our example, consideration of the distribution of renal function within a given patient population and related dosing for these fluoroquinolones revealed potentially important differences within the class.

Administration, Oral↗
PubMed1986

Population characteristics and absorbed dose to the population from nuclear medicine: United States--1982.

Those in the U.S. population who receive nuclear medicine examinations have been characterized by age and sex. Males received 42% of examinations while females received 58%. More than one-third of the examinations were done on persons older than 64 y of age and more than two-thirds on patients older than 45 y of age. The per caput effective dose equivalent from nuclear medicine procedures in 1982 was 140 muSv (14 mrem); whereas, the per caput age-specific effective dose equivalent to the U.S. population was 50 muSv (5.9 mrem). These can be compared with 2 mSv (200 mrem) from natural background.

Adolescent↗
PubMed1990

Population characteristics and cigarette yield as determinants of smoke exposure.

Relationships of population characteristics, smoking history, and cigarette yield with smoke exposure as measured by peripheral blood concentrations of thiocyanate, carboxyhemoglobin, nicotine and cotinine were sought in 170 male smokers. This population of smokers had significant elevations of serum thiocyanate, blood carboxyhemoglobin and plasma nicotine and cotinine concentrations as compared with an equal number of age- and sex-matched nonsmokers and these concentrations correlated significantly with past 24-hour cigarette consumption. Although the nicotine yield of the cigarette correlated significantly with plasma cotinine and marginally with plasma nicotine, the reduction in plasma nicotine and cotinine was not proportionate to the reduced yield of the cigarettes, suggesting that smokers partially compensate for the lower yields of their cigarettes. Blood levels of carboxyhemoglobin, nicotine and cotinine were also significantly associated with the weight of the subjects, presumably due to the relationship between weight and the volume of distribution. Univariate and multiple regression analyses provided evidence that coffee and alcohol consumption and years smoked also may be important determinants of smoke exposure.

Adult↗
PubMed2003

The San Daniele 2 Project: protocol description and population characteristics.

In 1990 we studied the prevalence and determinants of carotid atherosclerosis in an Italian general asymptomatic population (630 males and 718 females aged 18-99 years) living in the San Daniele district of the Friuli-Venezia Giulia Region. The global prevalence of subclinical carotid atherosclerosis was 25.4% in men and 26.4% in women. We considered intima-media thickness, non-stenotic plaque (< 40%), and stenotic plaque (> 40%). In the multiple logistic regression, the cross-sectional analysis of subjects aged 40 years showed a positive significant association between plaques/stenosis and age (p < 0.001), systolic blood pressure (p < 0.01), cigarette smoking (p < 0.0001), and the protective effect of high-density lipoprotein cholesterol (p < 0.037). In 2002 we decided to re-examine the initial cohort with the following objectives: prospectively evaluating the modifications of the previous carotid findings, their relationship with known and less documented cardiovascular risk factors and the predictive power of those variations on incident coronary and cerebrovascular events. We plan to evaluate the association of carotid plaque and carotid intima-media thickness with the genetic polymorphisms involved in atherosclerosis in survivors and finally to study the incidence and the determinants of atrial fibrillation in a general population. In this paper, we will describe the methodology of the screening and the cohort population characteristics. We have compared the San Daniele Project survivor cohort's characteristics to the current general population of the same age living in the Friuli-Venezia Giulia Region so as to extend the study's conclusions to the whole regional population.

Adolescent↗
PubMed1997

Factors influencing the attendance rate at accident and emergency departments in East London: the contributions of practice organization, population characteristics and distance.

OBJECTIVES: To examine the contribution of general practice organisation, population characteristics and distance to practice attendance rates at four local accident and emergency departments. DESIGN: Practice-based study examining variations in accident and emergency department attendance rates in 105 practices, using routine data from the Family Health Services Authority (FHSA), the District Health Authority and the 1991 Census. SETTING: East London and the City Health Authority, covering practices based in the inner city boroughs of Hackney, Tower Hamlets and Newham, and the City of London. MAIN OUTCOME MEASURE: Practice-based, age-standardized, adult attendance rates at accident and emergency departments in the year to 31 March 1994. RESULTS: Annual age-standardized practice accident and emergency department attendance rates ranged from 10.3 to 29.4 per 100 population. The mean practice attendance rate was 17.6 per 100 (95% CI 16.8-18.4). No significant relationship was found between attendance rates and practice characteristics (number and sex of general practitioner (GP) principals, presence of practice manager or nurse, computerization and training status). There were strong positive relationships between attendance rates and households not owner-occupied (R = 0.55, P < 0.001) and pensioners living alone (R = 0.55, P < 0.001). There were negative correlations with Asian ethnicity (R = -0.31, P = 0.002) and residents lacking amenities (R = -0.26, P = 0.007). The distance to the nearest accident and emergency department also correlated negatively with attendance (R = -0.27, P = 0.006). A backwards multiple regression model showed that 48% of the variation in attendance rates could be accounted for by six factors: percentage of households not owner occupied, percentage living in households without a car, percentage living in households lacking amenities, percentage of pensioners living alone, percentage of Asian ethnicity, and percentage living in households with a head born in the New Commonwealth and Pakistan. Optimal subsets regression identified a number of alternative models with similar explanatory value. CONCLUSIONS: Social deprivation is strongly linked with attendance rates at accident and emergency departments in East London. In contrast, the organizational characteristics of general practices appear to have no bearing on the rates. Both purchasers and providers need to take account of these findings when planning accident and emergency provision.

Adult↗
PubMed1980

Population characteristics and environmental factors that influence level and cause of mortality. A review.

Responsible evaluation of energy production effects on human health requires prior accounting for the socioeconomic, cultural, and climatic characteristics known to influence mortality rate and cause. Fifteen population characteristics and environmental variables (education, income, occupation, industrial mix, socioeconomic status, housing quality, climate, urban residence, geographic residence, internal migration, cigarette consumption, alcohol consumption, marital status, foreign birth or stock, and religious affiliation) and three age subgroups are discussed. An initial set of eight variables is indicated for mortality rate standardization, based on the reliability of their relationships with mortality. These eight variables are: education, occupation, industrial mix, urban residence, marital status, ethnic mix, and cigarette and alcohol consumption. Education and occupation are negatively related to mortality. Occupational exposure to toxicants (indicated by industrial mix), cigarette consumption, and alcohol consumption have positive linear relationships with various specific causes of mortality. Urban residence, marital status, and ethnicity have non-linear relationships with mortality and show consistent patterns for certain causes of death. In addition to these characteristics three age subgroups ( less than 1 year, 1-14 years, greater than or equal to 65 years) are discussed because of their relatively high or low rates compared to the rest of the population. A brief review of water and air pollution effects on mortality is included for completeness. Unique to this review is the quantitative summary (presented as an appendix) of the variables influencing adult mortality. It is a compilation of numerical relationships, derived either directly or indirectly from the published data, that support the choice of influencing variables.

Age Factors↗
PubMed2006

The North Jutland County Diabetic Retinopathy Study: population characteristics.

BACKGROUND: Several population-based studies have reported blood glucose levels and blood pressure to be risk factors for the development of diabetic retinopathy. These studies were initiated more than two decades ago and may therefore reflect the treatment and population composition of a previous era, suggesting new studies of the present population with diabetes. AIM AND METHODS: This cross-section study included 656 people with type 1 diabetes and 328 with type 2 diabetes. Crude prevalence rates of proliferative diabetic retinopathy, clinically significant macular oedema and several specific retinal lesions were assessed, together with their association to a simplified and internationally approved retinal grading. RESULTS: The point prevalence of proliferative retinopathy was found to be 0.8% and 0.3% for type 1 and type 2 diabetes. Equivalent prevalence rates of clinically significant macular oedema were 7.9% and 12.8%, respectively. The most frequently occurring retinal manifestations increased in number until retinopathy level 3, and then decreased. CONCLUSION: The point prevalence of proliferative retinopathy is lower than that found in previous studies, whereas it is increased for clinically significant macular oedema. These data suggest different risk factors for these clinical entities.

Adolescent↗
PubMed1988

[Population characteristics and biological properties of micrococci colonizing the skin of the breasts].

As shown in this investigation, the population characteristics of micrococci inhabiting the skin of the mammary glands make it possible to regard these microorganisms as the permanent members of microbiocenosis. Their proportion among all isolated strains was, respectively, 27.2% and 27.7% for nulliparous and pregnant women and their occurrence, 96.7% and 92.1%. The largest population of micrococci was registered at the nipple area of both left (934-1,956 colony-forming units per sq. cm) and right (1,092-2,134 colony-forming units per sq. cm) breasts. A decrease in the number of micrococci was observed at the above-mentioned areas during pregnancy, which was accompanied by changes in the specific and antagonistic profiles of the association. This occurred supposedly under the necessity of preserving its dynamic stability.

Adolescent↗
PubMed2006

Population characteristics of feral cats admitted to seven trap-neuter-return programs in the United States.

Internationally, large populations of feral cats constitute an important and controversial issue due to their impact on cat overpopulation, animal welfare, public health, and the environment, and to disagreement about what are the best methods for their control. Trap-neuter-return (TNR) programs are an increasingly popular alternative to mass euthanasia. The objective of this study was to determine the population characteristics of feral cats admitted to large-scale TNR programs from geographically diverse locations in the United States. Data from 103,643 feral cats admitted to TNR programs from 1993 to 2004 were evaluated. All groups reported more intact females (53.4%) than intact males (44.3%); only 2.3% of the cats were found to be previously sterilized. Overall, 15.9% of female cats were pregnant at the time of surgery. Pregnancy was highly seasonal and peaked between March and April for all of the groups. The average prenatal litter size was 4.1+/-0.1 fetuses per litter. Cryptorchidism was observed in 1.3% of male cats admitted for sterilization. A total of 0.4% of cats was euthanased because of the presence of debilitating conditions, and 0.4% died during the TNR clinics. Remarkably similar populations of cats with comparable seasonal variability were seen at each program, despite their wide geographical distribution. These results suggest that it is feasible to safely sterilize large numbers of feral cats and that the experiences of existing programs are a consistent source of information upon which to model new TNR programs.

Animals↗
PubMedDate not supplied

[The possibility of using the population characteristics of myelokaryocytes for the early diagnosis of radiation lesions].

The method of flow cytofluorimetry was used to study some population characteristics of bone marrow cells of control and irradiated rats. The simultaneous recording of cellularity and distribution of myelokaryocytes among the cell cycle phases was shown to give reliable results for determining the extent to which the organism was exposed at early times following irradiation.

Animals↗