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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↗

PubMed1982

Menstrual cycle changes with marathon training: anovulation and short luteal phase.

Fourteen normal women (self-selected from 180 women enrolled) in a marathon training clinic kept basal body temperature (BBT), mileage, and weight records for 48 cycles before the marathon. Entry criteria were: Age 20-45, gynecologic age greater than 5 years, no hormone use, or weight change in 3 months. The women were 35.2 +/- 5.6 years in age, 22.6 +/- 5.1 years gynecologic age, runners of 4.1 +/- 2.5 years with premenstrual symptoms, previous pregnancy 4/14, no infertility and 2/14 remote amenorrhea. BBT records were obtained and analyzed by Vollman's criteria (1977). There was no weight loss. 32/48 cycles were biphasic but only 16 were normal in the length of the premenstrual phase (PreM = luteal, nl 10 - 16 d) with a mean of 11.1 +/- 1.2 days. The other 16 biphasic cycles had short PreM phase of 6.4 +/- 1.8 days. Monophasic (M = anovulatory) cycles occurred in 16/48 records. Cycles which were abnormal (Short PreM and M) differed only in that usual run length was longer (9.6 - 9.9 miles) than in normal cycles (7.9 +/- 2.4 miles). Marathon training may be associated with normal length but M and short PreM type cycles.

Adult↗

PubMed1982

Urinary bladder dysfunction as a remedial disability in multiple sclerosis: a sociologic perspective.

Forty-two patients formed the sample for this study. They represented a self-selected subset of 115 patients who complained of bladder dysfunction as a disability secondary to multiple sclerosis. The study generated data on previous management and results, subjects' desired current intervention goals, urodynamic evaluation, and current intervention outcomes. Results indicated that bladder dysfunction disabilities are either ignored or mismanaged and that the disability can be reduced to the patient's satisfaction using clinically available diagnostic methods and indicated management.

Adult↗

PubMed1982

Surveillance for colorectal cancer in average-risk patients, familial high-risk groups, and patients with adenomas.

New concepts and technological advances have stimulated a heightened interest in the secondary prevention of colorectal cancer; the identification and eradication of premalignant lesions, and the detection of early cancer before the development of life-threatening consequences. This approach must be selective based on risk factors. Fecal occult blood testing and sigmoidoscopy have been applied to the average-risk patients, whereas x-rays, endoscopy, biopsy, and cytology have been applied to the high-risk groups for case findings and screening. Program results to date are encouraging for average-risk patients. Compliance with fecal occult blood testing and sigmoidoscopy has been high in motivated groups self-selected for entry into screening programs. The rate of positive slides, false-positivity, and predictive value for neoplasia has been acceptable. Dukes' staging of cancers has been favorable. False-negativity and mortality data are not yet available. Flexible sigmoidoscopy has been shown to be an effective substitute for rigid sigmoidoscopy in trained hands. Familial polyposis and Gardner's syndrome families have been well studied, but interest in the nonpolyposis inherited colon cancer families is relatively new. Followup procedures after polypectomy have been variable and only recently has there been an organized attempt to prospectively study the effectiveness of different followup plans. The National Polyp Study has been developed to address this issue.

Adenoma↗

PubMed1982

Physical activity in work and leisure time in relation to cardiovascular diseases.

The epidemic increase of coronary heart disease (CHD) was contemporary with a decrease of human energy expenditure. The hypothesis emerged that physical activity would protect against CHD. This hypothesis has been put on a test in several epidemiological studies of various designs. Physical activity in occupation has shown varying associations with CHD. In the Seven Countries Study, sedentary men experienced a higher ten-year incidence of CHD than the more active groups in only three of the countries included. By using the results of the Finnish East-West Study, which was carried out as a five-year continuation of the Seven Countries Study, some methodological requirements for epidemiological studies, and their influence on the results, were examined. While marked differences in the incidence of and mortality from CHD have been observed between various occupations, they cannot be attributed solely to physical activity. Vigorous self-selected physical activity during leisure-time, on the other hand, has predicted a protection from CHD in some occupationally or culturally homogeneous groups. This protection has not been ascribable to the "classical" risk factors. The discrepant results on occupational versus leisure-time physical activity as protection against CHD are a challenge for further studies. The physical working capacity is not necessarily increased by high heart rates in industrial work. New methods of classifying the character of occupational work and of quantifying physical activity habits are available. Muscularity has shown positive correlations with the risk factors blood pressure and heart rate at rest. Potent psychological predictors of CHD have emerged from recent studies. Their associations with occupational work and leisure-time habits deserve to be mapped out.

Adult↗

PubMed1981

Animal analog of alcohol dependence.

A review of rodent analogs of alcohol tolerance and dependence is presented. Depending on the control exerted by the experimental subject, analogs presently available are of three general types: involuntary, semivoluntary, and voluntary. With the involuntary analogs, the experimenter has total control of the administration of ethanol; that is, the selected dose is administered at a preselected schedule and rate. The following methods are in this category; inhalation, oral intubation, intragastric or intravenous schedule infusions, and SERT (sustained ethanol release tubes) implants. With the semivoluntary analogs the animals ingest ethanol via either the daily liquid or food supply, at their own pace. With the voluntary analogs, animals self-select ethanol orally, or self-infuse it intravenously or intragastrically. The characteristics, advantages, and disadvantages of each method are discussed. No method is ideal, and none satisfies all the criteria of an animal analog of "alcoholism." Therefore, the method of choice should be that which is most adequate for the particular aims of a given experiment.

Administration, Oral↗

PubMed1981

The Columbia population study. III. Volunteer status, educational background, and plasma total cholesterol level in a prepaid health care program.

From 1972 through 1975 a study of plasma lipid levels was conducted at the Columbia Medical Plan (a prepaid group practice in an upper-middle-class suburban community) in accordance with nationally standardized interview, blood-drawing and laboratory procedures of the Lipid Research Clinics Program. Data were obtained from a large group of volunteers from the plan as well as from subjects selected by random sampling from membership rolls. Of 2,591 fasting, nonpregnant adults (age greater than or equal to 20 years), 825 were volunteers and 1,766 were randomly selected subjects. Analysis of the plasma total cholesterol values indicated a possible association of volunteer status and higher educational levels with a lower plasma total cholesterol level. Age- and sex-specific comparisons confirmed this finding, although the magnitude of the differences was quite small from the standpoint of clinical risk. The data suggest that even within educational strata, self-selection for cholesterol screening was associated with a lower cholesterol level.

Adult↗

PubMedDate not supplied

Commitment to Underserved People (C.U.P.) program at the University of Arizona.

The C.U.P. (Commitment to Underserved People) Program was established at the University of Arizona College of Medicine to reinforce the commitment of a self-selected group of medical students to careers with medically underserved people and to help them acquire some of the special knowledge, skills, and attitudes essential to effective performance in such careers. The program brings together some preexisting curricular offerings and a number of additional extracurricular activities and experiences. The time demands on the participating students are significant, but not excessive. Support activities are an important aspect and include periodic group meetings, an annual retreat, faculty role models as students advisors, and personal counseling when needed. The program is coordinated by the Department of Family and Community Medicine, but relies on participation of faculty from other primary care departments and the cooperation of a number of community agencies and clinics. The C.U.P. Program was developed in response to an expressed student need, and students have continued to play an essential role in its design and direction.

Arizona↗

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↗