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Biomedical subjects

T A Sheldon

Publications and source records attributed to T A Sheldon.

125 records · Page 7Linked to original sources
PubMed1992

Race and ethnicity in health research.

'Race' and 'ethnicity' are increasingly being used as variables in health research. However, studies have been mainly descriptive and have not been used to develop and evaluate strategies to improve health care. In part this reflects the poor analytical standards. The status of the concepts of 'race' and 'ethnicity' as research tools are rarely considered and there is poor consistency in terminology. This paper gives an overview of the research literature and raises questions about the validity of 'race' and 'ethnicity' as epidemiological variables. The tendency to collect routine ethnic data and include ethnic variables in an ad hoc and uncritical way in the United Kingdom and other countries may help transform minorities into mere statistical categories and produce data and findings which reinforce stereotypes. Multiculturalist ethnic health explanations also tend to displace more material explanations of health outcomes. It is concluded that more thought and care is needed before data are routinely categorized by ethnicity, or race or ethnicity are included as variables in research.

Epidemiologic Methods↗
PubMed1991

Appraisal of a new scheme for prenatal screening for Down's syndrome.

OBJECTIVE: To appraise a new method of prenatal screening for Down's syndrome based on maternal serum concentrations of alpha fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin combined with maternal age--the "triple test." DESIGN: Examination of the cost effectiveness of the triple test relative to screening only by maternal age over a range of population detection rates. SETTING: Leicestershire Health Authority. MAIN OUTCOME MEASURES: Costs per affected fetus detected. RESULTS: The triple test is more cost effective than screening only by maternal age for risk cut off points for amniocentesis, resulting in a detection rate over 45%. The most efficient detection rate is around 60-65%, for which the cost per case detected is around 29,000 pounds, through screening with higher detection rates is still likely to be cost beneficial. CONCLUSIONS: Prenatal screening for Down's syndrome based on the triple test should replace screening based only on maternal age. Individual women's preferences should be elicited by the use of structured decision analysis in order to maximise utility and so increase the benefits of the screening programme.

Adult↗
PubMed1991

The student diary survey: a method of monitoring hospital-based medical education.

A new system of allocating the Service Increment for Teaching (SIFT) has recently been introduced which, by its nature, encourages universities to be more explicit about their teaching requirements. A detailed study of the quantity of teaching received by Leicester clinical medical students was carried out using a student diary. This instrument enables a data base to be constructed which is useful for academic and resource allocation purposes. This information can also be used to estimate the teaching time in the different sites and the source of funding of the teaching staff and thereby provide insights into the 'knock-for-knock' system of informal cost-sharing between universities and the National Health Service.

Clinical Clerkship↗
PubMed1990

A graphical presentation of the results of crossover trials.

1. Crossover designs are widely used in clinical trials. A graphical method of describing the data as well as visually indicating the extent of treatment * period interaction and overall treatment effect is presented. This plots the treatment differences between the periods for each individual against the mean of their treatment outcomes. It is recommended that this plot accompany the analysis of crossover trials in order to aid summary and interpretation especially for the non-statistician.

Blood Pressure↗
PubMed1990

The effect of short chain fatty acid supplementation on membrane electrolyte transport and blood pressure.

Eleven normotensive subjects with no family history of essential hypertension took part in a double-blind randomized placebo-controlled crossover study to examine the effects of supplementing a normal omnivore diet with miglyol. This resulted in a fall in diastolic blood pressure in both the supine and standing positions, achieving statistical significance for the standing diastolic pressures, following miglyol treatment. Miglyol is rich in caprylic (8:0) and capric acids (10:0), both short chain saturated fatty acids, and supplementation with this produced a significant fall in erythrocyte membrane oleic and linoleic acid (P less than 0.01 compared to placebo for each fatty acid), as well as a fall in the saturated fat palmitic acid (16:0) (P less than 0.01). These changes were not associated with any alterations in total erythrocyte sodium influx, bumetanide sensitive influx or sodium red cell intracellular or potassium content. In addition, body weight and urinary excretion of sodium and potassium did not change. These data indicate that this dietetic manipulation with an oil rich in short chain saturated fatty acids lowers diastolic blood pressure but not as a result of changes in membrane sodium handling. It is possible that the short chain fats displace the longer carbon chain fatty acids which are metabolically important to cellular integrity and it is in this way that blood pressure falls.

1-Deoxynojirimycin↗
PubMed1989

Radiation therapy of seminoma: 17-year experience at the Joint Center for Radiation Therapy.

One hundred and sixteen patients with stage I and II primary testicular seminoma were treated at the Joint Center for Radiation Therapy (JCRT) between 1968 and 1984. Complete follow-up is available for 114 patients (98%) with a median follow-up time of 6 years. Actuarial relapse-free survival (RFS) and survival for the entire group at 10 years were 94 and 86%, respectively, with 27 patients still at risk beyond 10 years. Actuarial RFS and survival at 10 years by stage were 97 and 92% for stage I, 93 and 81% for stage IIa, 100 and 100% for stage IIb, but only 75 and 51% for stage IIc. The difference in actuarial survival between stage IIc patients and stage I, IIa and IIb patients was significant (p less than 0.01). These results indicate that radiation therapy is excellent treatment for stage I and II seminomas as long as the largest mass of disease is not greater than 5 cm (stage IIc). Patients with stage IIc seminoma are now treated with cisplatin-containing combination chemotherapy followed by radiation therapy to areas of bulk disease. Although the majority of patients with stage II disease in this series received mediastinal irradiation, this is no longer recommended at the JCRT.

Actuarial Analysis↗
PubMed1989

Intraoperative radiation therapy for biliary tract carcinoma: results of a 5-year experience.

The results of a 5-year experience with use of intraoperative radiation therapy (IORT) in the management of locally advanced bile duct carcinoma are presented. Fifteen patients received IORT doses between 5 and 20 Gy for localized disease, which was either primary and resected with microscopic residual (2 patients), primary and unresected (10 patients), or recurrent (3 patients). Thirteen patients also received postoperative radiation therapy. The median survival of the 12 patients with primary disease was 14 months, with disease controlled in the porta hepatis in 5 of 10 evaluable patients. The three patients with recurrent disease survived 2, 9, and 11 months. There were two operative deaths, for an operative mortality of 13%. Acute and chronic complications are reviewed. Cholangitis is the most frequent in both categories. This aggressive approach in the therapy for advanced disease has an acceptable level of morbidity and may warrant the use of IORT as part of the management of biliary tract cancer.

Acute Disease↗
PubMed1987

Cardiac disease after mediastinal irradiation for seminoma.

One hundred twenty-four patients with seminoma (119 primary testis, five primary extragonadal) were treated between 1968 and 1984 at the Joint Center for Radiation Therapy. Fifty-seven of the 124 patients were treated with irradiation to the mediastinum as well as to an infradiaphragmatic field. One patient received supradiaphragmatic radiotherapy only. The remaining patients had radiation treatment limited to the infradiaphragmatic field only. Median dose to the mediastinum among the 58 patients was 2400 cGy. Four patients developed heart disease (one fatal myocardial infarction, one uncomplicated myocardial infarction, one constrictive pericarditis resulting in permanent total body anasarca, and one patient requiring aortic valve replacement and coronary artery bypass grafting for atherosclerotic disease) and two died suddenly. The two sudden deaths were thought to be cardiac in origin by the patient's primary physicians. All six complications occurred in the group that received mediastinal irradiation. No cardiac disease was manifested in the group not treated with mediastinal irradiation. This difference in the incidence of cardiac disease between the two groups is statistically significant (two sided, P = 0.019). Neither group had a statistically significant difference in cardiac disease rate from a normal population (Framingham study), although the ratio of observed to expected cardiac disease was 1.97 in the group receiving mediastinal radiation. Further experience from this and other institutions is necessary to confirm this finding.

Adult↗
PubMedDate not supplied

Modelling in economic evaluation: an unavoidable fact of life.

The role of modelling in economic evaluation is explored by discussing, with examples, the uses of models. The expanded use of pragmatic clinical trials as an alternative to models is discussed. Some suggestions for good modelling practice are made.

Clinical Trials as Topic↗
PubMedDate not supplied

The sexual adaptation of women treated for endometrial cancer.

This study explores the process of sexual adaptation in women treated for endometrial cancer. Methodology was primarily qualitative with in-depth interviews. Data were collected by means of semistructured tape-recorded interviews; detailed field notes; and quantitative measures of self-concept, self-esteem, body image, and satisfaction with sexual functioning. The quantitative instruments used to measure these constructs were the Tennessee Self-Concept Scale and three visual analog scales. A vivid picture of women's experience of sexual adaptation after treatment for endometrial cancer emerged. This study's findings indicate that the experience of sexual adaptation in women who undergo treatment for endometrial cancer is a process that evolves. This process begins with the onset of symptoms and continues beyond the completion of therapy. Factors that enhanced the adaptational process were identified by the participants.

Adaptation, Psychological↗