3 resultados para Concavifiability of preferences
em DigitalCommons@The Texas Medical Center
Resumo:
Epidemiological evidence suggests that fruit and vegetable intake is negatively associated with the development of several chronic diseases, including heart disease, some cancers and diabetes mellitus. Inadequate consumption of milk during developmental years is associated with osteoporosis. Consumption of fruit, vegetable and milk (FVM) declines from childhood to adolescence. Adolescent eating habits persist into adulthood; thus, understanding psychosocial factors such as self-efficacy, norms and preferences, is important for developing effective interventions. Preferences, one of the most consistent correlates of fruit and vegetable consumption in children and adolescents, may mediate the relationships between self-efficacy and norms and fruit and vegetable consumption. ^ Fifth grade students from one middle school in South Texas were followed for two years. Students completed lunch food records and questionnaires assessing fruit, vegetable and milk self-efficacy and norms and fruit and vegetable preferences. Principal component analyses identified four scales: Fruit Self-Efficacy, Vegetable Self-Efficacy, Fruit and Vegetable Norms, and Milk Influences. Reliability and validity of the four scales and emerging subscales were assessed using Cronbach's alpha and consumption data, respectively. Associations between longitudinal FVM consumption and self-efficacy and norms were tested. Additionally, the influence of preferences on the relationship of self-efficacy, norms and fruit and vegetable consumption was examined. ^ Confirmatory factor analyses confirmed four scales and subscales. Internal consistency and test-retest reliabilities were acceptable. Self-efficacy and norms were related to FVM consumption and changes in fruit and high fat vegetable consumption over the two-year period. While intake over the two-year period differed statistically, eating patterns were stable. Preferences mediated the relation between fruit self-efficacy and FV norms and fruit consumption. ^ In conclusion, self-efficacy and norms about consuming FVM at school appear to influence FVM consumption. Because eating patterns were similar over the two-year period, establishing healthy eating habits in elementary school is important. While FVM self-efficacy and norms influenced FVM consumption in children, only fruit preferences mediated the relationship of fruit consumption, self-efficacy and norms. Since the influences of FVM consumption appear to differ, interventions designed to increase consumption should target these differences and consider the specificity of self-efficacy and norms. ^
Resumo:
The discoveries of the BRCA1 and BRCA2 genes have made it possible for women of families with hereditary breast/ovarian cancer to determine if they carry cancer-predisposing genetic mutations. Women with germline mutations have significantly higher probabilities of developing both cancers than the general population. Since the presence of a BRCA1 or BRCA2 mutation does not guarantee future cancer development, the appropriate course of action remains uncertain for these women. Prophylactic mastectomy and oophorectomy remain controversial since the underlying premise for surgical intervention is based more upon reduction in the estimated risk of cancer than on actual evidence of clinical benefit. Issues that are incorporated in a woman's decision making process include quality of life without breasts, ovaries, attitudes toward possible surgical morbidity as well as a remaining risk of future development of breast/ovarian cancer despite prophylactic surgery. The incorporation of patient preferences into decision analysis models can determine the quality-adjusted survival of different prophylactic approaches to breast/ovarian cancer prevention. Monte Carlo simulation was conducted on 4 separate decision models representing prophylactic oophorectomy, prophylactic mastectomy, prophylactic oophorectomy/mastectomy and screening. The use of 3 separate preference assessment methods across different populations of women allows researchers to determine how quality adjusted survival varies according to clinical strategy, method of preference assessment and the population from which preferences are assessed. ^
Resumo:
Research has shown that disease-specific health related quality of life (HRQoL) instruments are more responsive than generic instruments to particular disease conditions. However, only a few studies have used disease-specific instruments to measure HRQoL in hemophilia. The goal of this project was to develop a disease-specific utility instrument that measures patient preferences for various hemophilia health states. The visual analog scale (VAS), a ranking method, and the standard gamble (SG), a choice-based method incorporating risk, were used to measure patient preferences. Study participants (n = 128) were recruited from the UT/Gulf States Hemophilia and Thrombophilia Center and stratified by age: 0–18 years and 19+. ^ Test retest reliability was demonstrated for both VAS and SG instruments: overall within-subject correlation coefficients were 0.91 and 0.79, respectively. Results showed statistically significant differences in responses between pediatric and adult participants when using the SG (p = .045). However, no significant differences were shown between these groups when using the VAS (p = .636). When responses to VAS and SG instruments were compared, statistically significant differences in both pediatric (p < .0001) and adult (p < .0001) groups were observed. Data from this study also demonstrated that persons with hemophilia with varying severity of disease, as well as those who were HIV infected, were able to evaluate a range of health states for hemophilia. This has important implications for the study of quality of life in hemophilia and the development of disease-specific HRQoL instruments. ^ The utility measures obtained from this study can be applied in economic evaluations that analyze the cost/utility of alternative hemophilia treatments. Results derived from the SG indicate that age can influence patients' preferences regarding their state of health. This may have implications for considering treatment options based on the mean age of the population under consideration. Although both instruments independently demonstrated reliability and validity, results indicate that the two measures may not be interchangeable. ^