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Results for “Self-selection”

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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↗

PubMed1968

Ethiopian cardiovascular studies. Case-finding by mass miniature radiography.

No large series of patients with cardiovascular disease has yet been reported from Ethiopia, where only limited means for investigation are at present available. The authors therefore studied the types of heart disease detected by mass miniature radiography in a largely self-selected population at the Addis Ababa Tuberculosis Centre, and examined the value of this method of cardiac case-finding. Rheumatic heart disease occurred in 34.8% of patients, but syphilitic aortitis, hypertension, "cardiomyopathy" and tuberculous pericarditis were also common. Endomyocardial fibrosis was not seen; this may be a further significant fact in the search for its cause. Mass miniature radiography is valuable for detecting symptomatic patients with the cardiovascular diseases mentioned above. The technique described in this paper could be used in other developing countries as it uses a single method of screening for 2 groups of diseases.

Adolescent↗

PubMed1983

Dietary practices of early life and age at death of rats with tumors.

The association between the age at death of rats that develop spontaneous tumors and their early life dietary practices and growth responses was investigated. The data were obtained from outbred male Charles River CD Crl:COBS CD (SD)BR rats maintained for life on a self-selection dietary regimen that permitted them to regulate their protein intake apart from energy intake. A series of multivariable models was derived, after the rats were grouped by tumor type, that accurately accounted for the age of death of the individuals in each class. The models that explain the variance in death age of rats that develop tumors also differed from the combination of factors for rats that do not develop tumors but succumb to other age-related diseases. Although dietary protein and measures of growth are ubiquitous features in these models, no one set of idealized conditions for longevity can be proposed.

Age Factors↗

PubMed1983

The impact of physical fitness evaluation on behavioural intentions towards regular exercise.

The Fishbein model was used to assess the impact of physical fitness evaluation with subsequent counselling by professional staff on individual intentions to exercise regularly. The subjects for this study were 172 self-selected adults seeking an evaluation of their current physical fitness. Experimental subjects were given a sequence of fitness testing and counselling; however, this did not significantly change the intention to exercise relative to control subjects. The only significant differences in intentions to exercise regularly were found (i) between subjects differing in fitness level (p less than .002), and (ii) between subjects differing in current exercise behaviour (p less than .001). Thirty-five percent (35%) of the variance in intentions to exercise were explained by a combination of (i) the two components of the Fishbein model (attitude and social norm) and (ii) an index of current physical activity. Since most of our subjects reported a positive intention to exercise, the most appropriate tactic for an increase of community activity may be to initiate policy changes facilitating behaviour in accordance with existing attitudes.

Adult↗

PubMed1984

Health care experience among employees prior to and after enrollment in a prepaid health insurance plan (HMO).

Company medical and benefit records of employees who were enrolled in prepaid health insurance plans (HMOs) in Minneapolis, Washington, D.C., and Seattle were reviewed for hospital and surgical utilization prior to as well as after their enrollment. Comparisons were made for the same calendar periods with closely matched employees who were covered by Blue Cross/Blue Shield (BC/BS). The results indicate that after enrollment the HMO subjects at each location had lower rates for hospital and surgical utilization than the BC/BS controls. For the period prior to enrollment, during which time coverage was through BC/BS, the prospective HMO subjects at two locations had lower hospital and surgical utilization than the controls. Possible explanations of this potential self-selection bias are discussed.

Adult↗

PubMed1983

Regulation of protein intake in adult dogs.

To determine whether adult dogs are able to regulate their intake of protein, 2-year-old female Beagles were allowed self-selection from 2 diets that differed in concentration of protein. Such a feeding regimen permitted the dogs to select for protein without affecting energy intake. Within the 1st week of the 4-week study, the dogs had established their pattern of protein intake. They selected approximately 30% of metabolizable energy from protein. Adult female rats offered the same diets also selected 30% of metabolizable energy from protein. The results indicated that adult dogs are able to regulate protein and energy intake.

Animals↗

PubMed1983

Selenium intake and urinary excretion in persons living near a high selenium area.

Selenium intake by adults consuming self-selected levels of four different diets averaged 209 micrograms. per day and correlated well with caloric and protein intake. Urinary selenium concentration averaged 0.108 microgram. per milliliter, and 24-hour excretion for the various diets averaged 58.0% to 88.6% of the intake. The data suggest that the RDA upper limit of 200 micrograms. of selenium per day and the suggested maximum urine selenium concentration may be too restrictive. The data further indicate that even though there are differences in the absorption of selenium from different sources, the average is about 70% for foods purchased in the Northern Great Plains area.

Adult↗

PubMed1983

Breast-feeding and sexual response.

Despite the recent trend toward more women breast-feeding their infants and extending breast-feeding for longer periods of time, there are few reports in the literature on the effects of lactation on female sexuality. A self-selected group of 121 presently or recently lactating women completed a detailed questionnaire on their breast-feeding experience and how it affected postpartum sexual response. It was found that the lactational amenorrheic period, which can last for a year or more, is a highly significant factor influencing sexual response. Compared with the prepregnancy period, 72 of the respondents (62.6 percent) reported experiencing less or no sexual desire while amenorrheic and nursing, 30 (26.1 percent) reported they had the same sexual desire, and only 13 (11.3 percent) said they experienced more sexual desire. These findings differ significantly from those of Masters and Johnson, who reported higher levels of sexual tension in all 24 of the lactating women they questioned. In addition, 39 women in this study (32.2 percent) volunteered the information in open-ended questions that they encountered a lack of vaginal lubrication and subsequent unpleasant coital experience when they were amenorrheic and lactating.

Amenorrhea↗

PubMed1983

Nutrition, aging and obesity: a critical review of a complex relationship.

Long-standing beliefs about the ill-effects of mild to moderate obesity have been called into question by recent epidemiological studies and by critical review of older studies. A review of these studies reveals that the effects of obesity on health and longevity is more complex than we had realized. An attempt is made to throw light on this relationship by reviewing the large number of laboratory studies on nutrition, aging and obesity. The first series of such studies showed that restriction of food intake, beginning early in life, greatly increased longevity. A second series of studies revealed that longevity could still be extended even if restriction of food intake did not occur until maturity. The third series of studies showed that dietary constituents as well as total calories influenced longevity. High-fat diets produce obesity and a shortened life span and there are significant differences in the effects of other dietary constituents at different times in the life cycle. The fourth series of studies, on dietary self-selection. are beginning to elucidate the role of food preferences in determining both obesity and longevity. Potential mechanisms of action include both body weight and immunological processes.

Actuarial Analysis↗

PubMed1980

Assessing the evidence on HMO performance.

HMOs contract to provide physician and hospital services to enrolled populations in return for fixed periodic payments. Total costs for HMO members are shown to be lower than for those enrolled in conventional insurance plans. But the explanation for this and related differences cannot be attributed solely to matters of efficiency, quality, or even consumer self-selection or physician satisfaction. Although public policy assumes that HMOs will encourage beneficial competitive responses by traditional health care providers, too little is known to predict the nature and extent of such probabilities.

Consumer Behavior↗

PubMed1980

Health status and health care use by type of private health coverage.

There is considerable speculation on the causes of the frequently observed lower rates of hospital use by group practice--or HMO--members than by persons covered by other health care arrangements. It is often asserted that HMO enrollees are a self-selected healthier population, or that their use of hospitals is not fully recorded. A major study in California of the actual health and use of hospitals by a representative sample of persons under age 65 showed these assertions to be unfounded.

Adolescent↗

PubMedDate not supplied

Health risk appraisal: process, problems, and prospects for nursing practice and research.

A number of methodological concerns and certain dimensions relevant to future development are generated in the above research: 1. The issue of test reactivity is especially critical in health risk appraisal instruments, since more advanced tools are designed to stimulate the recipient to take actions that might alter post-test results. Therefore, research studies using health risk appraisals need to control for the interaction effects of testing. Since health risk appraisals are reactive, the interaction of test effects with other experimental treatment (e.g. counseling) cannot be handled by use of non-reactive measures, as methodologists frequently suggest. 2. A second major threat to validity is the issue of experimental mortality. The clients who complete the health risk appraisal instrument are usually assumed to be self-motivated. Where engaged in large scale trials, however, their participation may be coerced at the outset but not enforced throughout the course of the study. Because of this some studies have a high proportion of dropouts. 3. Where this has not been the case, a third threat to validity, selectivity, is often a paramount concern, inasmuch as the populations who have subscribed to the instrument under their own motivation may be already pre-selected as very low risk individuals. In light of the paucity of controlled studies using health risk appraisals, it is difficult to draw conclusions regarding the state of the art. In summary, some general dimensions of the activity surround the development and use of health risk appraisals are: 1. The health risk appraisal appears to be more effective in motivating change with older rather than younger individuals. 2. Individuals given a health risk assessment within a supportive educational process do better than individuals exposed only to the results of a health risk appraisal. 3. Individuals given only a health risk appraisal and results without supportive education do better than individuals given no health risk appraisal. 4. Research participants and users of the instrument are, in almost every study, a self-selected group and appear to be healthier than the general population. One might question whether they are the more motivated population.

Disease Susceptibility↗

PubMed1982

The effects of running mileage and duration on plasma lipoprotein levels.

Eighty-one healthy, sedentary men aged 30 to 55 years were randomly assigned to supervised running (n = 48) or to sedentary control groups (n = 33) and followed up in a one-year trial. Measurements of plasma lipoproteins, fitness, and percent body fat were made at three-month intervals. Results and conclusions from this study are (1) that cross-sectional studies of lipoprotein concentrations in exercisers may be biased by a self-selection effect, since study participants with initially higher high-density lipoprotein cholesterol (HDL-C) and lower triglyceride concentrations were more easily persuaded to run more miles; (2) that plasma concentrations of HDL-C and low-density lipoprotein cholesterol (LDL-C) generally did not begin to change until a threshold exercise level (ten miles run per week) was maintained for at least nine months; and (3) that fitness increased and percent body fat decreased sooner and at lower exercise levels than required for HDL-C and LDL-C concentration changes.

Adipose Tissue↗

PubMed1980

The use of meditation--relaxation techniques for the management of stress in a working population.

The efficacy of meditation-relaxation techniques has been widely researched in the laboratory, but their effectiveness for management of stress in organizational settings is still relatively unexplored. The present study compared relaxation and control conditions as part of a program of stress-reduction in industry. A total of 154 New York Telephone employees self-selected for stress learned one of three techniques--clinically standardized meditation (CSM), respiratory one method meditation (ROM) or progressive relaxation (PMR)--or served as waiting list controls. At 5.5 months, the treatment groups showed clinical improvement in self-reported symptoms of stress, but only the meditation groups (not the PMR group) showed significantly more symptom reduction than the controls. The meditation groups had a 78% compliance rate at 5.5 months with treatment effect seen whether subjects practiced their techniques frequently or occasionally. The safe and inexpensive semi-automated meditation training has considerable value for stress-management programs in organizational settings.

Adult↗

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↗

PubMed1980

Effects of biotin on lipids and other constituents of plasma of healthy men and women.

A double-blind study of the effect of biotin supplementation (0.9 mg/day) of self-selected diets on plasma lipids and other plasma constituents was carried out in 40 men and women, age 30 to 60 years, for 71 days. Comparison of percent change from control levels showed significant treatment effects on more plasma constitutents than did comparison of the means of the actual levels. In an analysis of period of period changes, the largest differences were observed generally during the first two weeks after supplementation when small but statistically significant positive changes for biotin-treated men and women differed significantly from changes for the placebo-treated in total lipid, total phospholipid, and alpha + beta lipoprotein cholesterol. At the end of the study, these levels were at or below initial levels. Plasma biotin levels were elevated by biotin supplementation. There was a negative correlation between biotin levels and total plasma lipids. Responses os some lipid constituents of plasma were greater in volunteers who initially had elevated levels of lipids than in those who initially had normal levels of lipids. It is concluded that human requirements for biotin should be studied by new approaches and with modern techniques. Questions raised regarding the role bo biotin in the lipid metabolism of normal men and women should be investigated further.

Adult↗

PubMed1979

Gastric secretory and humoral responses to anticipated feeding in five men.

It is believed that humans anticipate appetizing meals by increasing vagally mediated gastric acid secretion. Studies were conducted on 5 normal male volunteers to characterize further the secretory response to anticipated meals. Plasma gastrin and glucose levels were monitored to assess the possibility that these humoral factors participated in the observed secretory changes. Subjects were not fed for 22 hr and were intubated at 10 AM. Basal gastric collections were begun, and at 1 PM on different days, subjects either (a) selected meals of choice prepared in their presence for 1 hr before nasogastric tube withdrawal and meal ingestion or (b) were not food-teased or fed. Gastric collections were obtained every 10 min during the "test" hour (1-2 PM) during both (a) and (b) studies and titrated for gastric acid. Blood samples for plasma glucose and RIA gastrin were obtained during basal and test hours every 10 min. Pentagastrin-stimulated maximal acid output studies were conducted on all subjects on separate days. Results showed a progressive and statistically significant rise in gastric acid secretion when an appetizing, self-selected meal was anticipated. The magnitude of this rise was 55% of the mean pentagastrin-induced acid response. This acid response did not correlate with changes in plasma glucose or gastrin. The study demonstrated that pure psychic stimulation may be as effective an acid stimulant as sham feeding.

Adult↗

PubMed1977

Enrollment choice in a mutli-HMO setting:the roles of health risk, financial vulnerability, and access to care.

Results of an analysis of enrollment decisions in HMO-type plans are reported. Previous studies concern dual-choice situations; this paper deals with a quadruple-choice situation involving one open- and two closed-panel HMO-type plans as well as Blue Cross/Blue Shield (BC/BS). The risk-vulnerability hypothesis is disaggregated into its components and the results show that there is no adverse health risk self-selection in an employed population. The hypothesis of economic vulnerability is maintained when tested in terms of per capita income rather than the previously used measure of family income. It is shown that those who enroll in any HMO-type plan are younger and have younger and larger families and lower per capita income than those who do not. No meaningful differences in terms of health status, health concerns, or prior utilization are found. Of the few differences found between those who enroll in closed- and open-panel HMO-type plans, having a private physician as the usual source of care is the most significant: those with an established physician relationship who join any HMO-type plan tend to follow their physician into the open-panel plan. The results should not be generalized to situations involving premium differences since the premium cost to subscribers in any of the plans considered here was fully paid by the employer. The validity of the results in terms of nonfinancial factors, on the other hand, is enhanced by the removal of cost considerations.

Adolescent↗