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Results for “Self-selection”

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At least 163 records · Page 9Linked to original sources

PubMedDate not supplied

Medical findings in nickel-cadmium battery workers.

Thirty-eight workers from a factory producing nickel-cadmium and other types of batteries came to us for medical evaluation. They included 21 women and 17 men (seniority 2-20 years, age range 31-63 years), and represented a self-selected subset of 700-900 ever-employed and 200+ recently or currently employed workers in the factory. Thirty-four worked on the nickel-cadmium assembly line. Symptoms and signs included: headache in 34; weakness, fatigue and lassitude in 26; dizziness in 16; pruritus and skin eruptions in 37; gingivitis, teeth loss and caries in 34; nasal congestion, nosebleeds and anosmia in 30; cough, phlegm production, wheezing and shortness of breath in 26; "asthma" in 14; bone pain in 18; urinary frequency, beta 2 microglobulinuria and kidney stones in 17; and sterility or multiple abortions (33) in 8 of 21 women. One additional patient had died from an "amyotrophic lateral sclerosis-like syndrome", while CT scans in six workers revealed brain atrophy. One other worker had leukemia, and two had died from cancer (lung and pancreas). Those who had worked for more than 10 years had more symptoms and signs than shorter-term employees, especially neurological illness, bone pain and urinary tract problems, including beta 2 microglobulinuria. Past blood and urinary cadmium levels were in the range of 1.6-8.7 micrograms/dl and 8-306 micrograms/l, respectively. Our findings indicated that: a) health risks for workers were not confined to the nickel-cadmium assembly line or to older workers, b) hazardous exposures still existed and illness appeared in new workers after a clean-up and intervention program, and c) exposures involved increased risks for renal disease and cancers. Finally, there is a need to control exposures and determine health risks in the full cohort of those ever employed, in the workers' children, and in the surrounding environment (air, ground, water) due to the dumping of waste from the plant.

Adult↗

PubMed1992

[Reference values of selected parameters of lung functions in the population of Bogdanka coal miners].

The aim of the study was to construct and test new equations for calculating FEV1, ITGV and FVC predictive values. Our examined population consisted of 2058 coal miners working underground in Bogdanka colliery (Lublin Basin). The following persons were excluded from out considerations: 1. smokers, 2. miners with pulmonary or allergic diseases history, 3. patients with chronic cough, sputum production or symptoms of chronic rhinitis, 4. persons with bronchial hyperreactivity. Finally, our standard group consisted of 353 coal miners. On the basis of our standard group data, new equations for calculating predictive values were formulated using the multiple regression model. According to these new equations and to equations elaborated by other authors, we calculated predictive values for FEV1, FVC and ITGV in our standard population and expressed results of measurements in percentages of different predictive values. Our predictive values in the standard population were significantly higher than the other authors' values. Percentages of predicted values were lower in the same comparison. We believe that observed differences are linked to a possible self-selection phenomenon in occupationally exposed population, relatively small maximum age of our standard group, possible differences in anthropometric features among examined populations and excluding hyperreactives. Our results seem to emphasize the need of greater attention to the paid on more restrictive use of the specially formulated equations in separate age compartments.

Adult↗

PubMed1992

A cholesterol reduction demonstration project: results from a challenge between two cities.

A competition was conducted between Jackson, MS and Lansing, MI to reduce blood cholesterol levels among self-selected individuals who were generally at high risk for elevated coronary heart disease. Baseline plasma cholesterol levels were measured and risk factor data were recorded for 13,710 participants in Jackson and 6,719 in Lansing (6.8% and 5.1% of the total populations, respectively). A six month educational campaign was conducted in both cities which included nutritional seminars, television shows, newspaper advertisements etc. From Jackson, 6,244 participants returned for the follow-up screening, and 2,404 from Lansing (46% and 36%). Subjects who reported changes in their diets had an average cholesterol reduction of 19 mg/dl (9%) in Jackson, and 2 mg/dl (1%) in Lansing (after adjustment for sex, baseline level, and age, P less than 0.01). In Lansing, participants were less likely to have college degrees, and were more likely to have participated because of concern with previously determined elevated cholesterol levels than Jackson participants.

Adolescent↗

PubMed1992

Economic benefits of secondary and tertiary cardiac rehabilitation: a critical study.

At least seven criticisms have been advanced to those suggesting economic benefit from secondary and tertiary rehabilitation: (i) many existing data sets are weak, (ii) many analyses have been limited to self-selected exercise participants, (iii) the distribution of benefits between different sectors of the economy has been ignored, (iv) programme participation is not necessarily synonymous with economic benefit, (v) the discount rate has been neglected, (vi) opportunity costs have not been considered, and (viii) possible increases in pension costs could outweigh supposed benefits. Although there are limitations in the original calculations of economic benefit, there are also weaknesses in their critique. Cost-effectiveness analysis has some attractions over cost-benefit analysis, because areas of fiscal and ethical uncertainty are avoided. Given that patients who develop chronic diseases will require some form of treatment, exercise offers an attractive option for both secondary and tertiary prevention, particularly if programmes have low facility and opportunity costs, and attention is directed to high-risk segments of the population. The challenge to incorporate the lessons from such analyses into governmental and corporate-decision making.

Cardiac Rehabilitation↗

PubMed1992

The effects of hospice coverage on Medicare expenditures.

This article reports on the findings of a study of the effects of the hospice program on Medicare Part A expenditures during the first three years of the program. The analysis compared treatment costs between hospice beneficiaries and nonbenefit patients with diagnosis of malignant cancer during their last seven months of life. It was estimated that during the first three years of the hospice program, Medicare saved $1.26 for every dollar spent on Part A expenditures. While the methodology included use of data from Medicare claims to adjust for confounding factors, including self-selection bias, our estimated savings might still have been overstated due to persistent selection effects. The extent of savings also varied according to the hospice's organization. Freestanding hospices, in contrast to those affiliated with either a hospital, nursing home, or home health agency, achieved the greatest savings by utilizing home care more extensively. However, we note that payment rates are increasing and the limits on the benefit period are being lifted, making it possible that the savings related to the hospice program found in this study will not continue. Of greater importance may be the long-term access and quality effects engendered by the benefit's preference for home care.

Age Factors↗

PubMedDate not supplied

High-risk sexual behavior among heterosexual undergraduates at a midwestern university.

Approximately 80% of a self-selected sample of 593 heterosexual undergraduate college students studied at a large Midwestern state university in 1988 had ever experienced penile-vaginal or penile-anal intercourse. One-fifth of the 477 sexually experienced women and men said they had had heterosexual and intercourse. The mean age at first vaginal intercourse was 17, while the mean age at first anal intercourse was about 18.5. Although less than four years, on average, had elapsed since the respondents' first vaginal or anal intercourse, females reported having had an average of 5.6 sexual partners, and males reported an average of 11.2 partners.

Adolescent↗

PubMed1992

Short- and long-term variability of selected indices related to nutritional status. II. Vitamins, lipids, and protein indices.

Five free-living women (ages 23-38 years) who consumed a self-selected diet and five women (ages 23-44 years) residing in a metabolic unit who were fed constant diet were assessed for variation in vitamin and general chemistry indices. Blood was drawn from these women once a month for five months, once a week for five weeks, and once a day for five days to assess analytical and biological variability of the indices. Analytical variability was determined by concurrently analyzing control samples prepared from plasma and serum pools. All samples were analyzed in duplicate. Of the measured indices, vitamins and lipids seemed to be the most variable. Diet had a significant effect only on ascorbic acid. We were unable to show any seasonal change for these analytes. Estimations of analytical variability, along with estimates of biological variability, and knowledge of dietary practices are essential when interpreting differences in analytes.

Adult↗

PubMed1991

A kinematic analysis of walking and physical fitness testing in elderly women.

Walking ability and physical fitness were assessed in 57 elderly Japanese women. Self-selected walking velocity at normal and fast speeds decreased markedly after age 60. The older age groups exhibited significant reductions in the lower limb joint displacements, due particularly to decreased angles at toe-off. The angular velocity of ankle plantarflexion during the stance phase declined markedly with age. A decrease in toe elevation during the swing phase and an increase in stance time in the process of aging suggested an increasing risk of stumbling over obstacles. Reductions in walking parameters with age correlated significantly with aspects of physical fitness tested, especially with items related to neuromuscular functions.

Aged↗

PubMed1992

The effects of gender-specific diagnosis on men's and women's response to infertility.

OBJECTIVE: To determine if differences could be distinguished between men's and women's emotional response to infertility based on the assignment of a gender-specific diagnosis. DESIGN: Gender-specific diagnoses were examined in relation to stigma, perception of loss, role failure, and self-esteem, using structured interviews. SETTING: Tertiary clinical care in private practice settings. PARTICIPANTS: Thirty-six self-selected volunteer couples undergoing infertility treatment. MAIN OUTCOME MEASURES: Stigma, perception of loss, role failure, and lowered self-esteem emerged from content analysis of structured interview data. RESULTS: No differences were found among women in their emotional response to infertility regardless of whether a female or male infertility factor was present, whereas men with a male factor experienced more negative emotional response to infertility than men without a male factor. CONCLUSIONS: Although both women and men are affected by infertility, their emotional response is significantly influenced by a gender-specific diagnosis. Men's response to infertility closely approximates that of women if the infertility has been attributed to a male factor but differs considerably if a male factor is not found.

Emotions↗

PubMed1992

Food intake of very obese persons: quantitative and qualitative aspects.

To document the caloric intake of very obese persons and investigate the food choices and dietary composition that maintain severe obesity, we studied the self-selected food intake required to maintain stable weight in two groups of very obese subjects: 11 inpatients with a mean weight 181% above desirable body weight and 35 outpatients with a mean weight 125% above desirable body weight. Qualitative and quantitative food intake were evaluated using records obtained on the hospital metabolic ward for the inpatients and using self-recorded food records for the outpatients. Absolute caloric intake in both groups was greater in proportion to the degree of obesity (deviation from desirable body weight); caloric intake per unit of lean body mass (kilocalories per gram urinary creatinine) was constant regardless of the degree of obesity and was essentially the same as that of normal nonobese persons. Food records indicated that the obese subjects maintained their high caloric intake by consuming mostly foods of high caloric density, with occasional binge eating. They largely avoided foods of low intrinsic energy density and modified-calorie foods, ie, foods with decreased fat, nonnutritive sweeteners, or fillers. By substituting foods of lower caloric density for usual food choices from the same food group, obese persons could decrease caloric intake by 20% and increase potential for notable weight loss.

Adult↗

PubMed1992

Maternal Type A behavior during pregnancy, neonatal crying, and early infant temperament: do type A women have type A babies?

It was hypothesized that type A behavior in pregnant women would be associated with increased neonatal crying and differential reports of infant temperament at 3 months. Type A behaviors during pregnancy were measured in a self-selected cohort of 72 healthy, primiparous, middle-class women. Their newborns were assessed at 48 hours of age and the women completed an infant temperament questionnaire at 3 months. Women who were classified as type A on the Job Involvement scale of the Jenkins Activity Survey had infants who cried more during a standardized neurobehavioral assessment compared with infants of women who were type B on the same scale. Women who were type A for Job Involvement rated their 3-month-old infants as more intense and less predictable in their responses to the environment. They were also more likely to be breast-feeding their infants at 3 months. This is the first study to examine the prevalence and nature of maternal type A behaviors during pregnancy and to show their relationship to neonatal crying behavior, to maternal report of early infant temperament, and to maternal breast-feeding.

Adult↗

PubMed1991

Does estrogen replacement therapy protect against rheumatoid arthritis?

The incidence of rheumatoid arthritis (RA) was compared in 2 cohorts of women aged 35-64. One consisted of 1,075 estrogen replacement therapy (ERT) users and the other was 3,251 women from general practice registers. Screening detected 32 cases; 8 postmenopausal control and 6 ERT women developed RA during the study period 1982-1986. This produced incidence rates of 19.7/10,000 and 12.3/10,000 years of observation for ERT and controls, respectively. The relative risks for ERT was 1.62 (95% CI 0.56-4.74) and reduced towards unity after adjustment for potential confounders. Despite the wide confidence interval, our data do not support the previous observation of a 4-fold reduction in RA incidence in ERT users. Indeed the incidence rate in the exposed group in this study exceeded current population estimates of RA incidence in postmenopausal women. We believe that the high incidence rates could be best explained by the self-selection for estrogen therapy at the menopause of those with undiagnosed joint symptoms. These findings underscore the difficulties in elucidating the relationship between ERT and RA.

Adult↗

PubMed1991

Fluid intake during an ultramarathon running race: relationship to plasma volume and serum sodium and potassium.

To assess the relationship between self-selected fluid intake patterns and changes in plasma volume and serum electrolytes during prolonged exercise, five men completed ultramarathon runs ranging from 50 to 100 km. There was a significant relationship between fluid intake and plasma volume changes but no changes occurred in either serum sodium or potassium. Subjects who ingested the most fluid during the race had a modest hemodilution without any changes in serum or potassium. This response may have been influenced by the consumption of beverages containing osmotically active solutes such as sodium and glucose.

Exercise↗

PubMed1991

Decreases in resting plasma beta-endorphin and depression scores after endurance training.

That endurance training changes resting plasma beta-endorphin (BE) at the same time that there are improvements in non-clinical depression was tested in medically healthy middle-aged men (40-60 years). Subjects were self-selected based on compliance into treatment (T, n = 10) and placebo (P, n = 6) groups. T attended an eight month fitness program. P had less than 50% attendance in the program. Treadmill tests at the pre and post program were used to estimate the Physical Fitness Score (PFS). The Minnesota Multiphasic Personality Inventory (MMPI) was used to measure depression. All psychological scores were within non-pathological, normal limits. BE was measured with the subjects fasting and resting in the early morning. BE, detected by radioimmunoassay, decreased (p less than .005) from pre 48.53 +/- 3.32 (SE) to post 31.73 +/- 4.43 pg/ml in T. The MMPI depression score also decreased in T (p less than .05) from pre 58.90 +/- 2.81 (SE) to post 53.20 +/- 1.48 T-score units. In contrast, the PFS increased in T (p less than .005) from pre 254.57 +/- 18.62 (SE) to post 304.94 +/- 15.95 PFS units. No pre to post program changes were detected in P. In conclusion, endurance training of eight months duration appeared to decrease the resting plasma BE concentrations and the MMPI depression scores of the middle-aged men in the present study.

Depression↗

PubMed1978

Update of naltrexone treatment.

To summarize, then, our work with naltrexone in a multi-modality treatment program indicates that it appeals to about 5-10 percent of narcotic addicts--those who conciously want to obtain drug-free status. It does significantly attentuate the effect of narcotics to the extent that they lose their reinforcing properties, and it has minimal side effects. Although we treated a self-selected population, it is noteworthy that about 10 percent of those who remained on naltrexone for more than a week were still opiate free 6 months after cessation of treatment. For some it appeared to be a turning point in their lives. It was the first time in years that they could live in their neighborhood and not be either intoxicated or occupied with the pursuit of narcotics. Our behavioral studies have identified a number of conditioned psychophysiological responses associated with the self-injection ritual. So far, although we have succeeded in extinguishing some of these responses, this has not resulted in an improved clinical outcome. We are currently working on more comprehensive behavioral treatments, but the clinical significance of these conditioned responses is uncertain at present.

Adult↗

PubMed1979

Potential effect of demographic and other variables in studies comparing morbidity of breast-fed and bottle-fed infants.

Comparing the morbidity of breast-fed and bottle-fed infants is confounded by inherent differences in breast-feeding and bottle-feeding mothers and their infants. Self-selection introduces complex variables encompassing much more than milk source used for infant feeding. Reasons for selecting breast or bottle feeding relate to demographic, socioeconomic, educational, ethnic, cultural, and psychological factors, as well as maternal and infant physical and emotional health. Many of the differences in the maternal populations may affect infant care practices, access to medical care, and infant health status. Studies published to date have not quantified these confounding effects and other potential biases in comparing morbidity to breast- and bottle-fed infants and the relationship between milk source and incidence of infantile disease remains in question. There is need for more cautious use of the available data and investigators must seek ways to design future studies to take into account the differences between breast-feeding and bottle-feeding mothers that affect both reported and actual infant morbidity.

Bottle Feeding↗

PubMedDate not supplied

[Treatment of the sick elderly in households accommodating several generations].

Multigenerational households with widowed persons aged 70 and more have been studied in order to determine the relationship between the following two groups of variables: (a) variables in the aged person describing the existence and degree of an organic mental impairment due to a dementive process and of other signs of physical illnesses. (b) variables in her daughter or daughter in law consisting of selfratings of psychosomatic complaints and of attitude-scales. Results were as follows: (a) If there were indications of personality changes due to an organic brain syndrom the relatives had a lower degree of life-satisfaction and more frequently suffered from psychosomatic symptoms and interpersonal stress than those, whose old relatives showed an unaltered personality. (b) A great number of comparisons failed to show any statistical differences. Especially severe physical illness, organic brain syndrome and the need for physical care were not related to life satisfaction, psychosomatic complaints, stress due to emotional involvement and the attitude towards home-care. Our attempt to explain the missing correlations led to the following factors: the small size of the sample, self-selection of the sample and possibly inappropriate operationalisation and measurement of variables. In respect to these results the ongoing study will be modified in some details: There will be a qualitative analysis of transcribed semi-structured interviews. The proportion of families with severely demented relatives will be increased. In an additional step we shall examine families, who have decided to transfer their old member into an institution.

Aged↗

PubMed1978

The effect of energy and nitrogen intake upon urea production in children with uremia and undernutrition.

Children with severe uremia who had anorexia were observed in a clinical study center where dietary energy and nitrogen intake could be compared with urea nitrogen production (UNPr). The children received a supplement of dextrose and amino acids at night, ate a self-selected diet and were encouraged to use carbohydrate supplements. Energy intake varied from 22 to 110 kcal/kg/day and nitrogen intake from 105 to 323 mg/kg/day. UNPr was reciprocally related to energy intake. Nitrogen intake minus UNPr, an index of nitrogen balance, was positively related to energy intake. UNPr was not related to nitrogen intake. Nitrogen intake (NI) and NI-UNPr were correlated and the slope of the regression was 1.15. We inferred from the data that low energy intakes (less than 60 kcal/kg/day) were associated with catabolic losses of body protein. Intakes above that level were associated with a low and stable rate of UNPr. The level of energy and nitrogen intake within the range observed limited the rate of nitrogen retention. Once maintenance requirements for energy and nitrogen were satisfied, the efficiency with which nitrogen was used for net protein synthesis was very high.

Adolescent↗