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At least 19 recordsLinked to original sources
PubMed1995

[Incidence, geographic distribution, age distribution, mortality and histologic verification of intraocular tumors in the Slovak Republic 1968-1989 (study)].

In the study is given the analysis of the data from National Tumour Registry of Slovak Republic--code 190 (ICD-9) in Slovakia over the period 1968-1989. The paper presents a survey of the incidence of notified malignant intraocular tumours: we notified 976 diseases--in male 528 (54%) and 448 in female (46%). Intraocular tumours were 0.3% of all the registered oncological diseases in Slovakia in male and also in female. A specific incidence in Slovakia was found to be 1,0/100,000 inhabitants in male, and 0.8/100,000 inhabitants in female and the registered data are comparable to those from surrounding countries in Europe. The mortality rate was found over 0.3/100,000 inhabitants. Microscopically verified were over 90% of the intraocular tumours.

Adolescent↗
PubMed1990

Mortality in fishermen: an unusual age distribution.

Age specific standardised mortality ratios (ASMRs) were compared for commercial fishermen under 55 years old and those who were aged 55 and older in the Canadian Atlantic coastal provinces of Nova Scotia, New Brunswick, and Prince Edward Island. The subjects were a cohort of 31,415 fishermen licensed by the Department of Fisheries and Oceans during 1975-83. Mortality was obtained by a computerised linking of the registry of licensed commercial fisheries and the Canadian Mortality Data Base. Fishermen under 55 had ASMRs between 1.4 and 1.7 for death from all causes and around 1.0 for death from non-accidental causes. The older fishermen had ASMRs as low as 0.6 for all causes and non-accidental causes. The same pattern was shown for death from specific causes such as ischaemic heart disease, accidents, and cancer, as well as for different years of entry into the cohort. This pattern differed widely from that of most other occupations. Dividing the cohort into owners and crew members showed that the high mortality ratios at younger ages existed in crew members only. It was concluded that the high death rates for fishermen under 55 had a socioeconomic component.

Accidents, Occupational↗
PubMed1997

Age-distribution dynamics and aging indexes.

I analyze the dynamics of the age distribution as some vital rates change. When the fertility or mortality rate declines, the age distribution often manifests a dynamic stochastic-dominance relationship. I also propose some alternative indexes for measuring population aging. These indexes are closely connected with the age-distribution dynamics and contain more refined information about the distribution of age among the old.

Adult↗
PubMed1991

Determining the initial age distribution for an age structured population.

"This paper deals with an inverse problem in age-structured population dynamics; the recovery of an unknown initial age distribution. We attempt to recover this function from overposed data which consists of either the total population over a time interval equal to the maximum life span of the species or the age structure of the population at a fixed later time. Existence, uniqueness and continuous dependence of the initial distribution function on the data are addressed. Some numerical simulations are presented to illustrate the feasibility of recovery using the methods of the paper."

Age Distribution↗
PubMed1999

The changing picture of hip fractures: dramatic change in age distribution and no change in age-adjusted incidence within 10 years in Central Finland.

The objective of this study was to find out if the age-standardized incidence of hip fractures has changed in 10 years in Central Finland. Patients with acute hip fracture admitted to Jyväskylä Central Hospital in 1982-1983 (n = 317) and in 1992-1993 (n = 351) were selected from the hospital discharge register and from contemporaneous records of the Department of Anesthesiology and the ward of traumatology. Earlier studies in Finland have indicated that there has been an increase in incidence rates. The results of this study show no change in the age-standardized incidence of hip fractures of men and women during the last 10 years. However, because of the change in the age distribution of the population, the number of hip fractures has increased by 11%. The mean age of the hip fracture patients increased from 75.4 years in 1982-1983 to 78.4 years in 1992-1993. In 1982-1983, 18.0% of the patients were > or =85 years. The corresponding figure in 1992-1993 was 30.2%. Therefore, we summarize that there has been a dramatic change in age distribution and no change in age-adjusted incidence within the last 10 years in central Finland.

Adolescent↗
PubMed1985

Pubic symphysis age distributions.

A further discussion of age assessment and palaeodemography requires detailed reviews of methods, especially pubic symphysis techniques. Before reanalysis of changes in symphyseal form, the initial steps in distributing ages must be examined. Use of the mean values for age scores gives age distributions that are not real, but subject to systematic distortions, and cumulative percentages of skeletal samples can be shown to reflect the mean ages. Distributing skeletal ages using 95% probability distributions provides a more accurate estimation of true ages for palaeodemography and a better basis for discussions of pubic symphysis aging techniques.

Adolescent↗
PubMed1986

Examination of the generalized age distribution.

The formula for the age distribution and other relationships that follow from it for any (non-stable) population presented by Preston and Coale are significant contributions to demography. The formulas summarize the relationships among various demographic measures precisely, and are formally analogous to the relationships that hold for stable populations. The significance of these formulas cannot be overstated; they allow us to understand clearly the relationships among demographic measures in any arbitrary population. However, when it comes to using them for estimating demographic measures when census data are defective, the method of estimation is still affected by defective data. The reason is that the series of age-specific growth rates reflects the observed census age distributions exactly so that any defects in the census data are summarized in the growth rates. This paper begins with the formulation of the discrete version of the "new synthesis" developed by Preston and Coale. With the discrete formulation, the three kinds of errors introduced when the continuous time formulas are applied to real data can be avoided. Then it is pointed out that when two accurate census data are available, the Preston-Coale procedure of "estimating" the age distribution at the second census is equivalent to checking the identity of the age distribution formula. Also "estimating" mortality by the procedure of Preston-Coale is shown to be equivalent to obtaining mortality directly from intercensal survival rates. That the procedure which involves the age-specific growth rates is equivalent to those that involve the intercensal survival rates may have escaped notice because there are no a priori constraints for patterns of age-specific growth rates to follow. The irregularity in growth rates due to defective data are not distinguishable from true irregularity that exists in the population, contrary to the well-known regularity in the pattern of survival rates in human populations.

Actuarial Analysis↗
PubMed2001

Age distribution of cancer in mice: the incidence turnover at old age.

We have studied cancer incidence in mice as a function of age in those cohorts where the rodents are allowed to live very close to their full natural lifetime. We find that the incidence rises as a function of age, but then flattens and turns over at an age of about 800 days. This behaviour is similar to that which we observed (Pompei and Wilson, 2001) in the Surveillance, Epidemiology, and End Results (SEER) data where the age distribution of human cancer incidence turns over at about age 80. Although other fits are possible, the three-parameter beta function model fits both the mouse data and the human data well. The beta model implies, and the data do not deny, the interpretation that cancer is not a certainty and mice may also outlive their cancers, although high-dose cohort results suggest cancer might be certain if dose is sufficiently high. Limited data suggest that the cancer age distribution, including the turnover, may be time shifted by dietary restriction.

Age Distribution↗
PubMed2006

Correlation of HER-2/neu overexpression with mammography and age distribution in primary breast carcinomas.

RATIONALE AND OBJECTIVES: HER-2/neu is a valuable prognostic and therapeutic marker in primary breast carcinoma. The objective of this study was to determine the mammographic and patient characteristics (age) that correlate with HER-2/neu overexpression in primary breast carcinoma. MATERIALS AND METHODS: HER-2/neu characteristics and preoperative mammograms were available in 498 patients with 543 primary breast carcinomas (526 invasive carcinomas and 17 ductal carcinoma in situ). HER-2/neu status was determined by immunohistochemistry and fluorescence in situ hybridization. For evaluation of patient age distribution, age was divided into 5 groups. For mammography, breast composition and abnormal findings were categorized. Abnormal findings were divided into mass, calcification, architectural distortion, asymmetric density, or none. RESULTS: For age distribution, women under than 50 years had more frequent HER-2/neu overexpression than women aged 60-69 years (P < .05). On mammography, there was no significant correlation between breast composition and HER-2/neu status (P > .05). Calcifications were more significantly frequent in carcinomas with HER-2/neu overexpression (56%) than in those without HER-2/neu overexpression (40%) (P = .001). Of the 242 carcinomas with calcifications on mammography, fine linear morphology was more significantly frequent in carcinomas with HER-2/neu overexpression (20%) when compared with those without HER-2/neu overexpression (10%) (P = .023). Diffuse distribution of calcifications was more common in carcinomas with HER-2/neu overexpression (11%) compared with carcinomas without HER-2/neu overexpression (5%) (P = .051). CONCLUSION: HER-2/neu overexpression in primary breast carcinoma is correlated with patients' age (under age 50) and calcifications at mammography.

Adult↗
PubMed1988

Age distribution of progressive multifocal leukoencephalopathy.

The age distribution is given of 79 cases of progressive multifocal leukoencephalopathy confirmed as JC virus infection. The data are compared with a published age distribution of multiple sclerosis onset in Vestfold County, Norway, and with published data from Rochester, Minnesota of the age distribution of viral encephalitis. In contrast to viral encephalitis, 61% of which occurs in children under the age of 10, PML has been identified only once in this age group. PML, like MS, is a disease of adult onset, peaking in the sixth decade of life. The reason for this late onset of a CNS disease caused by a ubiquitous childhood infection is still uncertain, but it may be related to maturation of susceptible cells in the brain, as well as to declining immunity associated with chronic disease and age.

Adolescent↗
PubMedDate not supplied

Age distribution of breast cancer in Lebanon: increased percentages and age adjusted incidence rates of younger-aged groups at presentation.

BACKGROUND: Breast cancer is the most common cancer in Lebanese women. Lebanon has no national cancer registry and the American University of Beirut Medical Center (AUBMC) is one of the largest hospitals in Lebanon and has a fully operational cancer registry. Earlier studies showed that it sees about one third of all cancer cases in Lebanon. METHODS: All female breast cancer patients recorded at AUBMC between 1983 and 2000 were evaluated. We used the sex-specific age distribution of 1995 Lebanese Population and Housing Survey to estimate the age-specific incidence of breast cancer in Lebanon. The results were calculated as number and proportion of cases, 10-year age-specific incidence rates, crude rates and age standardized rates (ASR) per 100,000 population. The ASR per 100,000 population was estimated by the direct method with the use of the World Standard Population. RESULTS: Between 1983 and 2000, there were a total of 16421 cancers of which 8007 were in women. There were 2673 female breast cancers, averaging 148 cases per year (Range:94-202). Almost half of cases (49.1%) were in women below the age of fifty. The mean age was:49.8 years +/- 13.9 years. Ten-year age groups distribution showed that 4.7% were below 30 years of age, 16.1% were 30-39 years, 28.3% were 40-49 years, 26.3% were 50-59 years, 16.9 % were 60-69 years, 6.1% were 70-79 years and 1.6% were 80 years of age or older. Twenty-two patients (0.9 %) had their age missing in the records. Overall ASR was 30.6, for a crude rate of 27.7. Age adjusted incidence rate had its peak in women aged 50-59, followed by women 40-49 then 60-69 with values of 96.3, 79.9 and 77.4 per 100,000 respectively. We also noted 19 male breast cancer cases corresponding to 0.7% of the 2692 combined total. CONCLUSIONS: The percentage of women with breast cancer in Lebanon seen at AUBMC in pre-menopausal and younger-aged groups is higher than those reported from western countries. Our results emphasize the need to search for possible environmental, lifestyle and/or genetic risk factors in Lebanon. Our study also shows the importance of implementing early detection and screening programs which, along with high quality mammography and medical care, can have a positive impact on survival, especially in younger-aged women.

Adult↗
PubMed2006

Success and failure of endoscopic third ventriculostomy in young infants: are there different age distributions?

OBJECTIVE: Patient's age and etiology of hydrocephalus are the most important factors influencing the success rate of endoscopic third ventriculostomy (ETV). Failure rates are reported to be particularly high in the first year of age. On the basis of our own data and a metaanalysis of the literature, we try to further define the impact of age on ETV success in infants younger than 1 year. MATERIALS AND METHODS: Only patients with a minimum follow-up of 12 months were considered. Between October 1994 and July 2004, 28 patients younger than 1 year underwent ETV in our institution. Age ranged from 8 to 311 days (median 96). The etiology of hydrocephalus was aqueductal stenosis (AS) in all patients (idiopathic in 13, posthemorrhagic in three, postmeningitic in four, and related to CNS or vascular malformation or to tumor in eight). ETV failure was defined as subsequent need for shunt implantation. The metaanalysis of the literature took into account reported series on ETV in infants with detailed data on age and etiology in every single patient. RESULTS: In our own patients, ETV was successful in 13 patients and eventually failed in 15. In the ETV success group, the median age was 200 days and the mean age was 176 days (range 13-311 days). In the ETV failure group, the ages were 105 days (median), 117 days (mean), and 8-299 days (range). The differences were not statistically significant. Age distributions in both outcome groups showed a tendency of failures to occur more frequently in the first 2-4 months of life. The separate analysis of patients with idiopathic AS yielded similar figures and distributions. The data from the metaanalysis of the literature corresponded to our own results. CONCLUSION: There is a clear impact of age on ETV failure rate even when excluding etiological factors. The probability of ETV success gradually increases during the first months of life. The consequence of these findings for decision-making as well as parental counseling is to try to weigh the age of the infant and its estimated impact on ETV success with other factors guiding the decision to perform ETV or shunt in the treatment of obstructive hydrocephalus.

Age Distribution↗
PubMed1993

Age distribution of erythrocyte population in women with twin pregnancy.

An evaluation of the age distribution of erythrocytes in twin gestation was performed. Based on previous studies on age distribution of erythrocytes in late pregnancy, we have proposed that a more pronounced shift in age distribution of erythrocytes in twin pregnancy may be expected. We have used the density distribution of cells method for evaluation of age distribution of erythrocytes in women with twin pregnancies. Control curves for pregnant and nonpregnant women were obtained from our recently published studies. The cumulative density distribution of cells curve of erythrocytes of women with twin gestation was evidently shifted to the right as compared with the curve of erythrocytes of women with single gestation. The shift in age distribution of erythrocytes may suggest that erythrocytes in women with twin gestation have a shorter life span as compared to the life span of erythrocytes in women with singles. The age distribution shift of erythrocytes in women with twin gestation may be attributed to human placental lactogen augmentation of erythropoietin action.

Adult↗
PubMed2003

Age distribution of three radiologic factors for lumbar instability: probable aging process of the instability with disc degeneration.

STUDY DESIGN: Cross-sectional study of 880 outpatients with low back and/or leg pain regarding age distribution of three radiologic factors. OBJECTIVES: To investigate the proportion and relationship of three individual radiologic factors with age on segmental instability in sagittal plane in consecutive age groups. SUMMARY OF BACKGROUND DATA: Previous studies revealed relationships between radiologic factors for instability and symptoms; however, little is known about the relationship between factors and age except in degenerative spondylolisthesis. METHODS: Excessive segmental motion, defined as more than 10 degrees angulation, more than 3 mm translation, and more than 3 mm slip in neutral position, at the L4-L5 segment in 880 outpatients (389 men, 491 women) with low back and/or leg pain aged from 14 to 84 years was investigated by 3 observers. The number and rate of the patients with each excessive motion were evaluated in continuous age groups of 5 years. RESULTS: The mean ages of patients with excessive angulation, translation, and slip in neutral position were 41.7, 50.0, and 62.8 years, respectively. Both rates of excessive angulation and translation showed two peak patterns demonstrating peaks in the teens and 20s groups and in the over 46 age groups; however, angulation was predominant in younger age groups and translation was predominant in older age groups. Slip in neutral position was frequently observed in age groups over 46 and increased with age. CONCLUSIONS: The presence of patients with excessive angulation and translation in younger age groups suggests they have a hypermobile segment with least degenerated discs. Different predominant patterns of these radiologic factors may reveal the probable aging process of the instability.

Adolescent↗
PubMed1981

[Notes on estimating the age distribution of emigrant surviving children].

"A procedure is described to obtain an age distribution of emigrant surviving children from the reports of such children obtained from women by a census or survey. A simple form of the procedure, requiring a minimum of calculation, is shown to work almost as well as the more elaborate form, and is recommended for most uses. "These new procedures, explicitly introducing an age model of migration, yield age distributions which are substantially different from, and probably more realistic than those obtained through the use of model fertility and mortality schedules alone.... The age distributions of migrant children [in Colombia] as obtained in this paper are compared with those obtained by Somoza.... The procedure described here produces a total almost 10 percent higher because it shifts the age distribution of the migrant children towards higher ages with lower proportions of surviving mothers." (summary in ENG)

Adolescent↗
PubMed2004

Estimating vital statistics and age distributions of measurable soil organic carbon fractions based on their pathway of formation and radiocarbon content.

Radiocarbon measurements have been used in combination with "bomb 14C" models to estimate turnover of soil organic carbon fractions. However, the bomb 14C models assume that all SOC fractions are formed directly from external inputs of carbon, which is not always valid because some SOC fractions may receive carbon from other SOC fractions. Due to the continuous inputs of organic carbon, we argue that the most appropriate way to describe the age of SOC is by an age distribution. We developed age distributed models of SOC fractions and derived analytical solutions to them. The models all assume that SOC fraction decay can be described by first-order kinetics, but differ in their assumptions about the pathway of SOC fraction formation. The solutions can be used to estimate age distributions at steady state of different SOC fractions based on their radiocarbon content. These age distributions can be used to calculate the mean age, mean residence time, and other vital statistics of each measurable SOC fraction. Furthermore, if a sequential scheme is used to isolate the SOC fractions, an estimated age distribution of the total SOC can be obtained by adding the contributions of each soil fraction. The age distributions can be very helpful in interpretations of soil organic carbon dynamics in different soils.

Carbon Radioisotopes↗
PubMed2005

Age distribution of MEG spontaneous theta activity in healthy subjects.

This study investigates the possible relevance of distribution and age variation of spontaneous theta activity (4-8 Hz) in normal subjects using magnetoencephalography (MEG) recordings. Spontaneous theta was recorded with a 151-channel MEG in healthy subjects; moreover, in a group of 10 subjects, simultaneous MEG-EEG was recorded in order to compare the two methods. Theta was divided in two sub-bands: T(A) (4-6 Hz) and T(B) (6-8 Hz). The pre-processed data were transformed into the frequency domain by Fast Fourier Transform (FFT)-based software by subdividing the data in epochs of 5 sec, on which FFT amplitudes are computed. Moreover, on all trials a simple model of a single electric current embedded in a spherically symmetric conductor was fitted automatically to the magnetic fields and projected onto an averaged MRI. The results obtained show that FFT-based theta power spectrum was distributed in adults with the highest power over the posterior parietal and occipital areas with T(B) dominance. The dipole analysis resulted in a mid-sagittal distribution, though the youngest group displayed theta dipoles fitting more posteriorly respect to the adults and the elderly. These results suggest that spontaneous theta activity is a diffuse and pervasive rhythm which shows some different topographical distribution among the age groups. Whether the prevalent posterior distribution of theta is the expression of distinct networks or the outcome of complex dynamics are questions of possible relevance in the organization of higher order processes.

Adult↗