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At least 19 recordsLinked to original sources
PubMed1975

Attributable risk, population attributable risk, and population attributable fraction of death associated with hypertension in a biracial population.

In 1961, blood pressure was measured in the 40-69-year-old segment of the population of Evans County, Georgia. Mortality was monitored for up to ten years. The relationship found between hypertension and mortality is characterized in this report by four parameters: attributable risk, prevalence, population attributable risk, and population attributable fraction. Attributable risk of death, a measure of the over-all impact of hypertension on those in each race-sex group with hypertension, is high in white males, black males, and black females, and is lowest in white females. Population attributable risk, a measure of the impact of hypertension on each entire race-sex group, is highest in black males and females due to the high prevalence of hypertension in blacks. It is somewhat lower in white males and lowest in white females. The fraction of all deaths attributable to hypertension (population attributable fraction) is highest in black females and lower in the other three groups. The population attributable fraction (ranging from 0.26 to 0.54 for systolic hypertension) is of such magnitude that if the 50% reduction in mortality achieved in the Veteran Administration Cooperative Study could be repeated in the general population, life expectancy after 40 years of age could be substantially increased.

Adult↗
PubMed1996

Nasopharyngeal cancer in a low-risk population: defining risk factors by histological type.

Nasopharyngeal cancer (NPC) is a major public health problem in parts of Southeast Asia and North Africa, but is rare among whites and blacks. Although infection with the EBV and genetic susceptibility appear to play large roles in high-incidence populations, migrant studies suggest that environmental factors may also be important. Aside from the high risks associated with ingestion of salted fish, surprisingly few other risk factors have been established from studies in endemic areas. We studied a low-incidence population to determine whether tobacco use, alcohol consumption, and certain medical conditions and treatments are related to NPC and to examine variations in risk by histology. We reasoned that new relationships might be best identified in the absence of strong causal pathways, such as intake of preserved foods and genetic susceptibility. A population-based case-control study was conducted from 1987 to 1993 at five cancer registries in the United States: western Washington, metropolitan Detroit, Connecticut, Iowa, and Utah. Controls were identified by random digit dialing and frequency matched to the gender and age distribution of cases at each registry. Telephone interviews were completed by 231 cases and 246 controls. We observed a strong dose-response relationship between cigarette smoking and risk of differentiated squamous cell carcinoma (test for trend, P < .001). The highest risk [odds ratio (OR), 6.5; 95% confidence interval (CI), 2.0-21.3] occurred among current smokers with a history of more than 60 pack-years. In contrast, there was no evidence that undifferentiated or nonkeratinizing carcinomas were associated with cigarette smoking. Similarly, a significant increase in risk was observed for the heaviest alcohol consumers (21 or more drinks/week) only for differentiated squamous cell carcinomas (OR, 2.9; 95% CI, 1.2-6.9). The associations with cigarettes and alcohol appeared to be stronger among persons 50 years or older. There was a suggestion that diagnosis with infectious mononucleosis (a marker of late infection with EBV) is linked with decreased NPC risk (OR, 0.4; 95% CI, 0.1-1.1). This report indicates that over two-thirds of differentiated squamous cell NPC cases arising in older persons in the United States can be accounted for by cigarettes and alcohol, but leaves unexplained cases arising in the young and carcinomas of undifferentiated or nonkeratinizing histology. Future studies of NPC need to take into account histology and age in evaluating these and other environmental and genetic risk factors.

Adult↗
PubMedDate not supplied

CF carrier testing in a high risk population: anxiety, risk perceptions, and reproductive plans of carrier by "non-carrier" couples.

PURPOSE: The risk perceptions, psychological status and reproductive plans of 52 carrier by "noncarrier" (mutation screen negative) couples is the subject of this report. METHODS: Cystic fibrosis (CF) carrier testing was offered to relatives of individuals with CF. RESULTS: In this population testing was not associated with any significant adverse psychological effects, reproductive uncertainty, or inaccurate risk perceptions. CONCLUSIONS: The results of this study have important implications in light of the recent NIH CF Consensus Panel recommendations that CF carrier testing be offered to all high risk adults and all couples planning a pregnancy or seeking prenatal testing.

Adult↗
PubMed1984

Precursor lesions of oesophageal cancer in a low-risk population in China: comparison with high-risk populations.

An endoscopic survey was undertaken in Jiaoxian, People's Republic of China, a population at low risk for oesophageal cancer, to determine the prevalence of precancerous lesions of the oesophagus, and this rate was compared with the prevalence observed previously in high-risk populations in Iran and Linxian, China. The study involved 252 subjects whose exposure to suspected risk factors was determined by a questionnaire and all of whom underwent physical examination and oesophagoscopy, including cytology and biopsy. Chronic oesophagitis, with endoscopic and histologic characteristics similar to those observed in the high-risk populations of Iran and Linxian, was found in 28% of the study subjects compared to 80% in Iran and 65% in Linxian. Oesophagitis accompanied by atrophy of the epithelium was found in 0.4% compared to 10.5% in Iran and 10.8% in Linxian. No case of dysplasia was diagnosed in Jiaoxian while this condition was diagnosed in 4% of the subjects examined in Iran and in 8% of those in Linxian. The findings suggest that these lesions are in fact precancerous. Vitamin analysis showed that riboflavin deficiency was widespread in Jiaoxian, as in Iran and Linxian, but was more severe in Linxian than in Jiaoxian. No significant difference was found in the mean levels of retinol, beta-carotene and zinc between the two populations.

Adolescent↗
PubMed1991

Routine examination by ultrasound for the detection of fetal malformations in a low risk population.

A low risk population was offered screening for malformations in the second and third trimesters of pregnancy. Of 16,763 scans of pregnancies in the second trimester, 61 malformations were identified (0.36%). In the third trimester, scanning of 10,752 pregnancies revealed 24 malformations (0.22%): in all, in a low risk population 0.58% major malformations were found. The sensitivity for noncardiac malformations of the second trimester scanning was 54.3 with a specificity of 99.9%. The malformations overlooked was a more benign spectrum than the cases diagnosed. The sensitivity for cardiac malformations was less than 20%.

Congenital Abnormalities↗
PubMed1980

Metabolic epidemiology of large bowel cancer. Fecal mutagens in high- and low-risk population for colon cancer. A preliminary report.

Because of potential significance of fecal mutagens in the pathogenesis of colon cancer, the dietary pattern and fecal mutagens of 3 populations with distinct risk for the development of colon cancer, a high-risk population in New York Metropolitan area (non-Seventh-Day Adventists), a low-risk population of vegetarian Seventh-Day Adventists in New York Metropolitan area and a low-risk population in rural Kuopio, Finland were studied. The average daily intake of protein was the same in the 3 groups, but the sources were different, a greater portion coming from meat in the New York non-Seventh-Day Adventists and from vegetables in Seventh-Day Adventists. The intake of fat was lower in Seventh-Day Adventists and higher in Kuopio and in New York non-Seventh-Day Adventists. The intake of dietary fiber was high in Kuopio compared to other groups. Fecal samples collected for 2 days were freeze-dried extracted with peroxide-free diethyl ether, partially purified on a silica-gel column and assayed for mutagenicity using the Salmonella/mammalian microsome mutagenicity test. The mutagenic activity was observed with Salmonella typhimurium tester strain TA98 without microsomal activation and with TA100 with and without microsomal activation in high-risk subjects from New York consuming a high-fat, high-meat diet. The incidence of fecal mutagen activity was higher in volunteers from New York consuming a high-fat, high-meat diet compared to low-risk rural Kuopio population. None of the vegetarian Seventh-Day Adventists showed any mutagenic activity.

Adult↗
PubMed1999

Ankle fusion in a high risk population: an assessment of nonunion risk factors.

Between July 1992 and April 1996, 88 ankle fusions were performed at our institution. Sixty-seven of these had adequate follow-up for evaluation for union of the fusion, including adequate records and/or radiographs. The average age of patients was 43 years. There were 37 men and 24 women. The charts were reviewed to determine what level of trauma had resulted in posttraumatic arthritis (low energy, high energy, or open fracture). Alcohol use, drug abuse, diabetes, peripheral vascular disease, psychiatric history, smoking, or technical problems were also assessed. A chi-square analysis was used to evaluate the statistical significance. Nineteen of sixty-seven ankle fusions progressed to nonunion (28%). Eighty-five percent of the patients had posttraumatic arthritis. Among 17 patients with a history of open trauma, nine patients developed a nonunion (P < 0.03). A trend toward significance was noted for patients who were smokers, drank alcohol, had diabetes, had a psychiatric disorder, or used illegal drugs. Even with current techniques, this study demonstrates that a high risk population in a trauma center is at risk for nonunion after an ankle fusion caused by multiple risk factors, including a history of open trauma, tobacco use, alcohol use, illegal drug use, a history of psychiatric disorders, or diabetes.

Adult↗
PubMed1999

Sensitivity and specificity of ultrasound for the detection of neural tube and ventral wall defects in a high-risk population.

OBJECTIVE: To test the hypothesis that with experienced operators, sonography alone is sensitive and specific for diagnosing open neural tube and ventral wall defects in a population at risk for these disorders. METHODS: Consecutive women at risk for a fetus with an open neural tube defect because of elevated maternal serum alpha-fetoprotein (MSAFP) or family history were evaluated prospectively using prenatal sonography. Amniocentesis was not done routinely but was done for specific indications, such as limited visualization by sonography, markedly elevated MSAFP, or other risk factors for fetal chromosomal disorders. Complete postnatal outcome information was obtained, and the diagnostic accuracy of sonography was compared with that of amniocentesis plus sonography. RESULTS: Sonography alone was 97% (66 of 68) (95% confidence interval [CI] 0.898, 0.996) sensitive and 100% (n = 2189) (CI 0.998, 1.0) specific in diagnosing open neural tube defect, and was 100% sensitive (n = 17) (CI 0.805, 1.0) and specific (n = 2240) (CI 0.998, 1.0) in diagnosing ventral wall defect. In two cases of neural tube defect, there were other suspicious findings on sonography, and amniocentesis was performed for confirmation. CONCLUSION: When used by experienced operators, prenatal sonography is sensitive and specific for the diagnoses of neural tube and ventral wall defects in a targeted at-risk population.

Abdominal Muscles↗
PubMed1987

Dracunculiasis in Africa in 1986: its geographic extent, incidence, and at-risk population.

This paper presents a preliminary assessment of the geographic extent and estimates of the incidence and the population at risk of dracunculiasis in Africa. Nineteen countries are known to be affected, in a belt extending right across the northern part of the continent south of 18 degrees N, and in east Africa extending almost to the equator. Annual incidence is estimated to be 3.32 million, and the at-risk population is approximately 120 million. These data provide an initial baseline on which the success of control measures now being initiated in Africa can be assessed.

Africa↗
PubMed1997

Are risk factors for conversion to NIDDM similar in high and low risk populations?

Mexican Americans have an increased risk of non-insulin-dependent diabetes mellitus (NIDDM) relative to non-Hispanic whites which is only partially explained by their excess overall obesity and unfavourable body fat distribution. Non-diabetic Mexican Americans have hyperinsulinaemia and insulin resistance relative to non-Hispanic whites. We therefore hypothesized that the insulin resistance might be a more important predictor of NIDDM in high-risk populations characterized by obesity and insulin resistance, while compromised insulin secretion might be a more important risk factor for NIDDM in low-risk populations. We assessed the ability of ethnicity (Mexican American vs non-Hispanic white), age, overall adiposity (body mass index [BMI]), unfavourable body fat distribution (as assessed by waist-to-hip ratio [WHR]), glucose tolerance (impaired glucose tolerance vs normal glucose tolerance), fasting insulin and compromised insulin secretion (as assessed by increment in insulin to the increment in glucose over the first 30 min of an oral glucose tolerance test (delta I30/delta G30)) to predict future NIDDM. In the 8-year follow-up of the San Antonio Heart Study, NIDDM developed in 11.7% (107/914) of Mexican Americans and in 5.0% (18/362) of non-Hispanic whites (p < 0.001). Multivariate predictors of NIDDM by multiple logistic regression analysis included increased age, BMI, WHR, fasting insulin and impaired glucose tolerance and decreased insulin secretion. The strongest independent predictors of NIDDM were high fasting insulin and decreased insulin secretion. These risk factors predicted NIDDM equally well in high and low-risk populations.

Adult↗
PubMed1999

Delivering prevention: the role of public programs in delivering care to high-risk populations.

A successful program of prevention or early detection should have a high level of population coverage and should ensure that high-risk populations are targeted. In practice, relatively little attention has been paid to the tendency toward greater use of preventive care by populations at lower risk, in other words, for higher use by the wealthy than by the poor. Current delivery patterns of preventive care raise questions as to how to organize these services more effectively. Physician-based delivery of preventive care in a fee-for-service system seems to result in Canadian patterns of use that are fairly similar to those found in the United States. Universal free insurance alone does not appear to be enough to counteract the failure to target preventive care toward the least-healthy groups. Appropriately-run Canadian provincial programs may be able both to expand coverage and to target high-risk populations. The population coverage for three measures directed toward prevention or early detection--childhood immunization (which in Manitoba has been offered through a long-standing provincial program), screening mammography (a new provincial program), and cervical cancer screening (no provincial program)-are compared using longitudinal administrative data from Manitoba. The discussion emphasizes the role of provincial programs and the possibilities for using population-based data to help provide cost-effective care to high-risk populations.

Adolescent↗
PubMed2000

Incidence of sensitivity to Anisakis simplex in a risk population of fishermen/fishmongers.

BACKGROUND: Anisakis simplex, a fish and cephalopodes parasite, can cause either gastrointestinal symptoms or allergic reactions in humans on eating/handling contaminated fish. OBJECTIVE: The aim of our study was to determine the capacity of Anisakis simplex to induce specific IgE production and allergic reactions following eating and handling fish in a population at risk. METHODS: We determined the levels of total IgE, specific IgE, and eosinophil count in 28 fishermen/fishmongers (group A) and 15 healthy donors (group B). A skin prick test (SPT) with extracts from Anisakis and the most common species of fish in our country, were also carried out. RESULTS: Specific IgE to Anisakis were found in 14 subjects of group A (13 of them had a positive SPT to the same extract) and none of group B (only one subject had a positive SPT). The SPT with fish extracts was positive in 4 patients of group A but in none of group B. Subjects in group A with specific IgE to Anisakis showed higher total IgE levels and eosinophil counts compared with either other individuals of the same group or to those of group B. CONCLUSIONS: These results indicate that fishermen/fishmongers are a population at risk for Anisakis simplex sensitization and suggest that this kind of sensitization should also be investigated not only in subjects like fishermen/fishmongers who live in countries where fish is likely to be contaminated with Anisakis simplex parasites, but also in those who handle fish for other reasons.

Adolescent↗
PubMed1996

The population risk as an explanatory variable in research synthesis of clinical trials.

The population risk, for example the control group mortality rate, is an aggregate measurement of many important attributes of a clinical trial, such as the general health of the patients treated and the experience of the staff performing the trial. Plotting measurements of the population risk against the treatment effect estimates for a group of clinical trials may reveal an apparent association, suggesting that differences in the population risk might explain heterogeneity in the results of clinical trials. In this paper we consider using estimates of population risk to explain treatment effect heterogeneity, and show that using these estimates as fixed covariates will result in bias. This bias depends on the treatment effect and population risk definitions chosen, and the magnitude of measurement errors. To account for the effect of measurement error, we represent clinical trials in a bivariate two-level hierarchical model, and show how to estimate the parameters of the model by both maximum likelihood and Bayes procedures. We use two examples to demonstrate the method.

Adrenergic beta-Agonists↗
PubMed1994

Proinsulin and specific insulin concentration in high- and low-risk populations for NIDDM.

Hyperinsulinemia and insulin resistance have been implicated as risk factors for the development of non-insulin-dependent diabetes mellitus (NIDDM). Recent data suggest that proinsulin may comprise a large proportion of immunoreactive insulin in subjects with NIDDM and possibly in those with impaired glucose tolerance (IGT) as well. Increased proinsulin concentrations are thought to be an early indicator of a failing pancreas. We examined proinsulin, insulin (using an assay that does not display appreciable cross-reactivity with proinsulin), and the fasting proinsulin:insulin ratio in 206 nondiabetic Mexican-American (a high-risk population for NIDDM) and 123 nondiabetic non-Hispanic white (a low-risk population for NIDDM) participants in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. Mexican-Americans had significantly higher fasting and 2-h proinsulin and insulin levels but similar fasting proinsulin:insulin ratios compared with non-Hispanic whites. After statistical adjustment for age, body mass index, waist-to-hip ratio, and glucose tolerance status, Mexican-Americans continued to have higher fasting and 2-h insulin and fasting and 2-h proinsulin concentrations but similar proinsulin:insulin ratios compared with non-Hispanic whites. The fasting proinsulin:insulin ratio was higher in 85 subjects with NIDDM compared with subjects with IGT or normal glucose tolerance (0.31, 0.09, and 0.07, respectively). Thus, nondiabetic subjects from a high-risk population for NIDDM are hyperinsulinemic (using an assay that does not cross-react with proinsulin) and, further, do not secrete more proinsulin relative to insulin itself than do nondiabetic subjects from a low-risk population.

Diabetes Mellitus, Type 2↗
PubMed1991

[Study on screening for primary liver cancer in high risk population of an endemic area].

Positive HBsAg males aged 30-59 years in Qidong were considered a high risk population for primary liver cancer (PLC). A screening study was conducted among 3,958 high risk population which were assigned randomly to a screening group or to a non-screening group. 2,580 persons were screened by alpha-fetoprotein (AFP) once every six months, the incidence rate of PLC was 1,599.38 per 100,000 person-years (PYs), and that in non-screening group with 1,378 persons was 729.39 per 100,000 PYs. Screening survey was also done among 2,332 males aged 30-59 years with negative HBsAg at one-year interval, and the incidence was 128.76 per 100,000 PYs. 26 (86.67%) of 30 PLC patients found in the screening survey were stage I PLCs, but none in 11 out-patients was found in this stage. This study suggests that periodic AFP screening for high risk population is suitable for the high-incidence area, and is one of the effective ways of secondary prevention for PLC.

Adult↗
PubMedDate not supplied

Data assessing the usefulness of screening obstetrical ultrasonography for detecting fetal and placental abnormalities in uncomplicated pregnancy: effects of screening a low-risk population.

To investigate the usefulness of screening in low-risk populations, the authors evaluated the yield of ultrasonography for detecting abnormalities in 678 clinically uncomplicated pregnancies. The yield of ultrasonography in high-risk women who were referred for amniocentesis was remarkably similar to the yield in other women. All four diagnoses of twins were correct, but overall only six of 12 initial ultrasound diagnoses of fetal demise or fetal anomalies were confirmed at delivery. Of the eight major fetal anomalies present at delivery, including two cases of Down's syndrome, three had been detected by ultrasonography; none of the nine minor anomalies had been detected, usually because they were too small or might be detectable only at a later gestational age. Although ultrasonography may have a nearly perfect predictive value for certain anomalies, on average, in this study, positive ultrasonography increased the probability of an adverse outcome of pregnancy from 5.3% to 36%, while a normal ultrasound examination decreased the probability to 4.4%. These data, which emphasize the implications of screening a low-risk population, suggest that recommendations regarding routine screening obstetrical ultrasonography should await sufficiently large controlled trials demonstrating consistent clinical benefit, in terms of reassurance or of providing a baseline for future comparison or in terms of improved outcome at a reasonable cost.

Abnormalities, Multiple↗
PubMed1996

[Screening of high-risk population susceptible to stroke and their characteristics].

High-risk population susceptible to stroke were screened with self-designed scoring method for quantitatively evaluating the risk of stroke in 550,000 frame population in 22 areas with different incidence of stroke during 1990-1993 and its related factors were analyzed by a principal component analysis method. Results showed scoring value correlated positively with probabilities of stroke, which suggested its objectivity and feasibility. The first principal component correlated positively with age, blood pressure, blood sugar, blood cholesterol, body mass index, ect., which reflected the characteristics of high risk population susceptible to stroke, and 71.43% of those with stroke were in the first principal component class. The proportion of the population with the first principal component correlated positively with the incidence of stroke in the area, therefore, stroke prevention should be focused on such population.

Adult↗