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Biomedical subjects

K McPherson

Publications and source records attributed to K McPherson.

At least 127 records · Page 7Linked to original sources
PubMed1992

HRT: an analysis of benefits, risks and costs.

A cost-effectiveness analysis of hormone replacement therapy (HRT) was undertaken to assess the relative benefits of different treatment strategies, and to identify which factors most influence cost-effectiveness. The current lack of conclusive evidence on the effects of HRT, especially in relation to combined therapy and cardiovascular disease, necessitated the use of a large number of assumptions in our model. In terms of net health benefits, the potential reduction in cardiovascular disease would have greatest impact, and would overshadow any small increase in breast cancer risk possibly associated with long-term use. Net expenditure by the NHS will depend critically on the direct costs of treatment, rather than on any indirect costs incurred or averted as a result of side-effects. In terms of cost-effectiveness, long-term prophylactic treatment of hysterectomised women and treatment of symptomatic women with a uterus compare favourably with other accepted health care interventions.

Breast Neoplasms↗
PubMed1992

The epidemiology of hysterectomy: findings in a large cohort study.

OBJECTIVE: To examine patterns of hysterectomy in the Oxford-Family Planning Association (Oxford-FPA) study in relation to age, parity, social class and calendar period (-1974, 1975-79. 1980-84, 1985-89). DESIGN: The Oxford-FPA study is a large scale prospective study of 17,032 women recruited from 1968-74 and still under observation. SETTING: Seventeen family planning centres throughout England and Scotland. SUBJECTS: At recruitment the 17,032 women were all white, British, married, aged 25-39 and willing to co-operate. In addition, they were using the pill or an intrauterine device or a diaphragm as their method of contraception. MAIN OUTCOME MEASURE: Hysterectomy rates per 1000 woman-years of observation in various subclasses of the data. RESULTS: Up to the end of 1989, 1885 (11.1%) of the 17,032 women in the study were known to have undergone hysterectomy. Fibroids were the most common cause followed closely by menstrual disturbances in the absence of fibroids (hereafter referred to as 'menstrual disturbances'). Social class had a modest influence on hysterectomy rates. Hysterectomy for fibroids, prolapse, endometriosis and 'other reasons' showed little trend with calendar period while hysterectomy for menstrual disturbances and for cancer showed a sharp increase with calendar time especially at ages 30-39. Hysterectomy generally tended to increase with age and showed a strong relation to parity; in particular, hysterectomy for fibroids fell with parity and hysterectomy for menstrual disturbances rose sharply with parity. Using lifetable methods, it was estimated that almost 20% of the women in the study would have had a hysterectomy by age 55. CONCLUSIONS: The results give insights into factors affecting hysterectomy rates. Of particular interest is the modest influence of social class, the strong influence of parity and the rise in rates with calendar time at ages 30-39 for those undergoing hysterectomy for menstrual disturbances or cancer, but since the cohort is not directly representative of the population, some caution is required in extrapolating these findings. The estimated hysterectomy rate of about 20% by age 55 is in line with other similar estimates for the United Kingdom.

Adult↗
PubMed1992

Who benefits from electroconvulsive therapy? Combined results of the Leicester and Northwick Park trials.

This paper describes the results obtained by combining data from the Northwick Park and Leicester randomised controlled trials of ECT. Patients who suffered from depression in which retardation and delusions were features and who received real ECT had a significantly improved outcome at the end of four weeks of treatment (as measured by improvement in the HRSD) in comparison with those who received simulated ECT. However, this treatment effect was not detectable at six-month follow-up. Patients who were neither retarded nor deluded did not benefit significantly from real as opposed to simulated ECT.

Antidepressive Agents↗
PubMed1992

Assessing symptom improvement after elective prostatectomy for benign prostatic hypertrophy.

BACKGROUND: Elective surgery for benign prostatic hypertrophy requires estimates of likely improvement. METHODS: Data are from a prospective study of all patients without cancer who underwent transurethral prostatectomy. After eliminating patients for whom surgery was not elective, we examined symptom improvement. RESULTS: Surgery was effective in reducing symptoms for all but those with very mild preoperative symptoms. For the remainder, the average level of postoperative outcomes achieved was independent of the initial symptom severity. CONCLUSIONS: Elective prostatectomy is effectiveness for improving symptoms. The improvement is typically sustained, and for some symptoms improvement continues during the first year after surgery. Patients with severe symptoms were as likely to achieve the same level of postoperative improvement as were patients with less severe problems initially. However, patients with very mild symptoms benefited little or none from surgery.

Adult↗
PubMed1991

Overview of azathioprine treatment in multiple sclerosis.

The efficacy of azathioprine in the treatment of multiple sclerosis was assessed by meta-analysis of the results of all published blind, randomised, controlled trials. 793 patients were enrolled in 5 double-blind and 2 single-blind studies. After 1 year of treatment, the increase in Kurtzke disability status score was no different in treated and control groups, but at 2 years there was a small difference (-0.22; 95% confidence interval [CI] -0.43, 0.003) in favour of azathioprine treatment; this difference was sustained, but not increased, after 3 years. The probability of freedom from any relapse during 1, 2, and 3 years' treatment was significantly greater in the azathioprine-treated group (relative odds over 3 years 1.97; 95% Cl 1.27, 3.04), but it is debatable whether the slight clinical benefits of azathioprine outweigh its side-effects.

Azathioprine↗
PubMed1991

Reduction in total under-five mortality in western Nepal through community-based antimicrobial treatment of pneumonia.

Pneumonia is a leading cause of death among children world wide but those at highest risk in developing countries have limited access to clinical services; effective and low-cost alternatives are a global public health priority. We have done a controlled intervention trial among 13,404 children under five in Jumla, Nepal, which relied exclusively on indigenous community health workers to detect and treat pneumonia according to the World Health Organisation decision strategy, with a five-day home-treatment course of oral co-trimoxazole. No other health services were provided, and referral of children to hospital was not practicable. During the three-year study, 2101 deaths were recorded. The programme led to a 28% reduction in the risk of death from all causes by the third year of services (relative risk 0.72, 95% confidence interval 0.63-0.82), with a significant trend (p less than 0.02) of lower mortality with greater duration of the programme. The greatest benefit was among infants. In addition to reduction in deaths due to pneumonia, there was a significant reduction in deaths due to diarrhoea and measles, indicating that reduction in pneumonia morbidity had considerable carry-over effect. Our findings show that indigenous community workers can effectively detect and treat pneumonia, and reduce overall child mortality, even without other primary care activities.

Administration, Oral↗
PubMed1991

Post-myelogram headache--physiological or psychological?

Psychological aspects of post-lumbar puncture headache have hitherto received little attention. A hundred consecutive patients admitted for elective myelography were studied. Post-myelogram headache was assessed by an independent observer and found to be strongly associated with normality of the test (P less than 0.001). Psychological testing showed a trend between Hospital Anxiety Depression score and normality of myelogram as well as development of headache, although this did not achieve statistical significance. This study suggested that there is a large psychological as well as organic component to post-myelogram headache.

Adolescent↗
PubMed1991

Reliability of questionnaire responses as compared with interview in the elderly: views of the outcome of transurethral resection of the prostate.

Three hundred and eighty-eight men undergoing transurethral resection of the prostate for benign prostatic hypertrophy completed a presurgical questionnaire and three follow-up questionnaires 3, 6 and 12 months after surgery. The questionnaires covered details of prostatic symptoms, general health, and expectations and results of surgery. At each follow-up point 40 randomly selected patients were interviewed by two female research assistants. The response rate to the questionnaires was over 90% at each follow-up point while that for the interviews was lower at around 80%. We examine the reliability of the postal questionnaires in assessing health status by comparing questionnaire and interview responses, with a view to the wider employment of such a method in the follow-up of surgical patients. In general, and as reported elsewhere, responses to questions on easily defined topics are highly comparable between questionnaire and interview. Responses to more subjective questions are moderately reliable, but with a tendency for postal questionnaires to underestimate a patient's health problems. It is difficult to assess the reliability of the questionnaires with regard to questions of an intimate nature since such questions caused embarrassment during interview with consequent incomplete responses.

Adult↗
PubMed1991

Do doctors and patients agree? Views of the outcome of transurethral resection of the prostate.

In an attempt to establish the extent to which patients and doctors agree on the outcome of health care, the pre- and postoperative states of health of 388 men undergoing transurethral resection of the prostate for benign disease were studied. Generally, high levels of concordance (greater than 70%) were obtained. The strongest agreement was for clearly defined events, such as episodes of acute retention (95%); the weakest agreement occurred over the most subjective symptoms, prognostic expectations, and ambiguous terms (around 60%). The level of agreement was not associated with any characteristics of the patient, surgeon, or treatment.

Cystoscopy↗
PubMed1991

Oestrogens and breast cancer: exogenous hormones.

Oestrogens are administered to women as contraceptive agents and as treatment for menopausal symptoms. This article reviews the epidemiological evidence concerning the risk of breast cancer related to both types of medication. It is generally accepted that long-term; high-dose menopausal oestrogen administration without accompanying progestogen is associated with a moderate increase in breast cancer risk; and that combined oral contraceptives reduce the risk of benign breast disease (as well as ovarian and endometrial cancer). The effect of oral contraceptives on breast cancer risk, however, is less certain. Possible reasons for the lack of agreement between recently conducted case-control studies are discussed, concentrating specifically on the effect of possible latency, being the sum of a prolonged induction plus pre-clinical period, in explaining the discrepancies.

Adolescent↗
PubMed1991

Combined progestin and estrogen (oral), and other forms of hormonal contraception.

This review examines controversies concerning serious side effects of oral contraceptives. Current concerns about the pill are with either relatively small excess risks or with very long-term effects, which need not be small. The main outstanding questions are the effects on cardiovascular disease of lowering doses and the effects on breast cancer of oral contraceptive use at a young age. In the end, the possible effects on breast cancer incidence cause the most concern. It is argued that most epidemiologic studies are too small to reliably detect effects among particular subgroups and it is possibly too soon to know what the long-term effects of using oral contraceptives while young on breast cancer actually are. However, complacency is contraindicated.

Breast Neoplasms↗
PubMed1990

Relation between general practices' outpatient referral rates and rates of elective admission to hospital.

OBJECTIVE: To examine the variation in rates of admission to hospital among general practices, to determine the relation between referral rates and admission rates, and to assess the extent to which variations in outpatient referral rates might account for the different patterns of admission. DESIGN: A comparison of outpatient referral rates standardised for age and sex and rates of elective admission to hospital for six specialties individually and for all specialties combined. SETTING: 19 General practices in three districts in Oxford Regional Health Authority with a combined practice population of 188 610. MAIN OUTCOME MEASURES: Estimated proportion of outpatient referrals resulting in admission to hospital, extent of variation in referral rates and admission rates among practices, and association between admissions and outpatient referrals. RESULTS: Patients referred to surgical specialties were more likely than those referred to medical specialties to be admitted after an outpatient referral. Overall, the estimated proportion of patients admitted after an outpatient referral was 42%. There were significant differences among the practices in referral rates and admission rates for most of the major specialties. The extent of systematic variance in admission rates (0.048) was similar to that in referral rates (0.037). Referral and admission rates were significantly associated for general surgery; ear, nose, and throat surgery; trauma and orthopaedics; and all specialties combined. For most specialties the practices with higher referral rates also had higher admission rates, casting doubt on the view that these practices were referring more patients unnecessarily. CONCLUSION: Rates of elective admission to hospital vary systematically among general practices. Variations in outpatient referral rates are an important determinant of variations in admission rates.

England↗
PubMed1990

Dietary intake and plasma lipid levels: lessons from a study of the diet of health conscious groups.

AIM: To re-examine the contentious relation between diet and plasma lipids within a population. DESIGN: Cross sectional sample from a large prospective cohort study of people eating different diets in Britain. Blood samples and diet records collected from subjects. SUBJECTS: Volunteers eating one of four distinct diets--namely, vegans, vegetarians, fish eaters who do not eat meat, and meat eaters. 52 Subjects selected from each group. METHODS: Examination of the relation between nutritional intake recorded in a four day dietary record and plasma lipid concentrations of subjects measured in blood samples collected previously. RESULTS: After controlling for age, sex, and body mass index, the correlation between plasma total cholesterol and the Keys score (which includes dietary cholesterol and saturated and polyunsaturated fat) was 0.37 (p less than 0.001). The mean saturated fat intake in all groups was low (6-14% of energy), but polyunsaturated fat intake was high, so mean total fat intake was generally above that recommended. A high dietary fibre intake was not associated with high carbohydrate intake. Plasma high density lipoprotein values were not associated with any measure of fat intake, but there was a significant correlation of 0.24 between high density lipoprotein values and alcohol intake. CONCLUSIONS: The nature rather than quantity of dietary fat is an important determinant of cholesterol concentrations. Health conscious individuals select a fat modified, rather than a low fat--high carbohydrate diet. National cholesterol lowering dietary advice should be reconsidered.

Adult↗
PubMed1990

Sequential stopping rules in clinical trials.

This paper reviews aspects of the development of sequential analysis of clinical trial data in medicine and suggests simple strategies for progress. The emphasis is on the pragmatic and ethical requirements of aspects of the design of phase III trials and in circumstances of genuine uncertainty characterized by much clinical experimentation. In particular consideration is given to the consequences of determining sample sizes from incorrect estimates of treatment effects. Armitage's work on sequential trials is traced to simple group sequential procedures based on repeated significance tests to minimize expected sample sizes in a wide class of experimental situations.

Clinical Trials as Topic↗
PubMed1990

Ethics committees and health services research.

Ethics committees in Britain were set up to consider clinical research. Increasingly, however, they are receiving applications for health services research which often involves several or many centres. The performance of 23 ethics committees was examined through a case-study of an application for a multi-centre non-experimental study of prostatectomy. Although all the committees approved the study, long delays occurred (mean 11.5 weeks, range 3-32 weeks), particularly in teaching districts which dealt with large numbers of applications. The composition of the committee and the frequency with which it met were not associated with the time taken to reach a decision. Some delays might be reduced by improving the design of the application forms and ensuring that at least one member of the committee has an understanding of health services research methods. Although such measures might improve the performance of committees, applicants are likely to remain in a logistic trap between funding bodies, clinicians, and ethics committees. In addition, until committees temper their concern for individualistic medical ethics with a collective ethic of the common good, health services research may continue to experience delays and difficulties.

Decision Making, Organizational↗
PubMed1990

Mortality in a cohort of long-term users of hormone replacement therapy: an updated analysis.

OBJECTIVE: To reexamine the mortality experience of a cohort of long-term users of hormone replacement therapy (HRT) in comparison with that reported previously for the same cohort of women, paying particular attention to cardiovascular mortality, deaths from breast and endometrial cancer, and deaths attributed to suicide or suspected suicide. DESIGN: Longitudinal cohort of 4544 long-term users of HRT amongst whom mortality is being monitored prospectively in comparison with expected rates in the female population of England and Wales (taking account of age and calendar period). SUBJECTS: 4544 women, all of whom were recruited from specialist menopause clinics around Britain and had taken at least one year's continuous HRT at the time of recruitment to the study. MAIN OUTCOME MEASURES: All cause mortality, cardiovascular mortality, deaths from female cancers, deaths attributed to suicide or suspected suicide. RESULTS: Overall mortality (based on 236 deaths over the entire study period from recruitment to December 1988) remained significantly lower than expected on the basis of national rates (relative risk (RR) 0.56, 95% confidence limits (CL) 0.47-0.66). When specific causes were considered, the only mortality ratios greater than unity were for injury, poisoning and violence (1.54, 95% CL 1.02-2.06), and for suicide and suspected suicide ('suicide') (2.40, 95% CL 1.68-3.11). Comparison of the ratios for the 112 additional deaths with those obtained in our previous analysis revealed that one of the few ratios to show any increase was that for breast cancer mortality. This rose from a significant deficit of 0.55 (95% CL 0.28-0.96) in the earlier period to 1.00 (95% CL 0.55-1.45) in the later period. There was also a suggestion of an increase in breast cancer risk with increasing duration since first use of HRT. Most of the other cause-specific ratios were very similar over the two periods. The ratio of death from all circulatory diseases was notably lower in the later analysis (RR 0.37, 95% CL 0.15-0.58) than in the earlier analysis (0.51, 95% CL 0.36-0.69), as were all of the subcategories of cardiovascular death. The mortality ratio for cancer of the ovary and uterine adnexa fell from 1.12 in the previous analysis to 0.63 (95% CL 0-1.41). The mortality ratio for 'suicide' also decreased, but was only slightly lower in the later period. As before, however, there was evidence of a relatively high prevalence of prior psychiatric problems amongst the recent 'suicide' deaths, suggesting that the excess of deaths from 'suicide' may be a manifestation of selection. CONCLUSION: These data are consistent with a beneficial effect of HRT on cardiovascular diseases, although updated information comparing progestogen-opposed and -unopposed treatment is not available. The increase in breast cancer mortality contrasts with the pattern for all other specific causes examined; taken together with the suggestion of an increase in breast cancer mortality with increasing interval since first exposure to HRT, this finding is somewhat worrying.

Breast Neoplasms↗