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Biomedical subjects

T Lancaster

Publications and source records attributed to T Lancaster.

At least 19 recordsLinked to original sources
PubMed1998

Systematic review of dietary intervention trials to lower blood total cholesterol in free-living subjects.

OBJECTIVES: To estimate the efficacy of dietary advice to lower blood total cholesterol concentration in free-living subjects and to investigate the efficacy of different dietary recommendations. DESIGN: Systematic overview of 19 randomised controlled trials including 28 comparisons. SUBJECTS: Free-living subjects. INTERVENTIONS: Individualised dietary advice to modify fat intake. MAIN OUTCOME MEASURE: Percentage difference in blood total cholesterol concentration between the intervention and control groups. RESULTS: The percentage reduction in blood total cholesterol attributable to dietary advice after at least six months of intervention was 5.3% (95% confidence interval 4.7% to 5.9%). Including both short and long duration studies, the effect was 8.5% at 3 months and 5.5% at 12 months. Diets equivalent to the step 2 diet of the American Heart Association were of similar efficacy to diets that aimed to lower total fat intake or to raise the polyunsaturated to saturated fatty acid ratio. These diets were moderately more effective than the step 1 diet of the American Heart Association (6.1% v 3.0% reduction in blood total cholesterol concentration; P<0.0001). On the basis of reported food intake, the targets for dietary change were seldom achieved. The observed reductions in blood total cholesterol concentrations in the individual trials were consistent with those predicted from dietary intake on the basis of the Keys equation. CONCLUSIONS: Individualised dietary advice for reducing cholesterol concentration is modestly effective in free-living subjects. More intensive diets achieve a greater reduction in serum cholesterol concentration. Failure to comply fully with dietary recommendations is the likely explanation for this limited efficacy.

Cholesterol↗
PubMed1997

Systematic reviews.

Explore the source record for details and available documents.

Clinical Medicine↗
PubMed1996

Treatments for postherpetic neuralgia--a systematic review of randomized controlled trials.

BACKGROUND: A number of different therapies have been used for postherpetic neuralgia. We decided to conduct a systematic review of existing randomized controlled trials. OBJECTIVE: To determine the efficacy of available therapies for relieving the pain of established postherpetic neuralgia. METHODS: We performed a systematic review, including meta-analysis, of existing randomized controlled trials. Eleven published trials and one unpublished trial were identified which met the inclusion criteria and were included in the current review. RESULTS: Pooled analysis of the effect of tricyclic antidepressants demonstrate statistically significant pain relief (OR 0.15, CI 0.08-0.27). Pooling of the results of the three trials comparing the effects of capsaicin and placebo could not be done due to heterogeneity. This heterogeneity was mainly attributable to an unpublished trial which differed in terms of the dose and duration of treatment. When this study was omitted, no heterogeneity was found and the pooled analysis revealed a statistically significant benefit (OR 0.29, 95% CI 0.16-0.54). However, problems with blinding in patients using capsaicin may have accounted for the positive effect. One small study of vincristine iontophoresis compared to placebo also yielded a favourable result (OR 0.05, 95% CI 0.01-0.26). Other treatment evaluated include lorazepam, acyclovir, topical benzydamine, and acupuncture. We found no evidence that these are effective in relieving pain associated with postherpetic neuralgia. CONCLUSION: Based on evidence from randomized trials, tricyclic anti-depressants appear to be the only agents of proven benefit for established postherpetic neuralgia.

Analgesics↗
PubMed1996

Which smokers are helped to give up smoking using transdermal nicotine patches? Results from a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Nicotine replacement therapy is effective in helping people to give up smoking. The three forms now available--transdermal patches, chewing gum and nasal spray--deliver nicotine at different rates and to different levels. Therefore, it might be expected that smokers with different characteristics, and at different levels of nicotine dependence, will be helped more by one or other method. AIM: The aim of the study was to examine whether the effectiveness of transdermal patches is related to nicotine dependence or to other smoker characteristics and to investigate factors predicting smoking cessation using patches. METHOD: Data from a randomized, double-blind, placebo-controlled trial of nicotine transdermal patches were analysed retrospectively. The trial, conducted in 1990-1992, involved 1686 patients recruited from 19 general practices in Oxfordshire. The main outcome measure was continuous smoking cessation from 8 to 52 weeks after the start of patch use, biochemically validated at 12, 24 and 52 weeks. The effectiveness of the patches was measured by the relative odds of sustained cessation using nicotine patches compared with placebo patches. RESULTS: Nicotine transdermal patches were more effective in smokers with moderate nicotine dependence [odds ratio (OR) 1.94; 95% confidence interval (CI) 1.24-3.04] than in mildly or highly dependent smokers (OR 0.98; 95% CI 0.58-1.65) (difference in ORs P < 0.05) and more effective in those aged 24-49 years (OR 1.89; 95% CI 1.24-2.87) than in older smokers aged 50-65 years (OR 0.88; 95% CI 0.49-1.59) (difference in ORs P < 0.05). Abstinence from smoking in the first week of the trial was the strongest predictor of sustained cessation and was more common among smokers using nicotine patches than those using placebo patches (33% of 842 compared with 22% of 844; P < 0.001). Of first-week abstainers, 25 and 28% of 277 and 182 in the nicotine and placebo groups, respectively, achieved sustained cessation compared with 4% of 565 and 2% of 662 first-week smokers. CONCLUSION: Nicotine transdermal patches were most effective for smokers with moderate nicotine dependence and for younger smokers. Early abstinence from smoking was the strongest predictor of sustained cessation. A week's trial of the patch proceeding to longer term use if abstinence is achieved may be an effective policy.

Administration, Cutaneous↗
PubMed1996

Effect of the Medicare Catastrophic Coverage Act on payer source changes among nursing home residents.

The Medicare Catastrophic Coverage Act (MCCA) of 1989 was designed to expand Medicare's post-acute care benefits, reduce copayments, and raise the asset limit for Medicaid eligibility. This analysis uses a semi-Markov transition model to estimate the effect of the MCCA on changes to Medicare coverage and the spend-down rate among 5,551 new nursing home admissions followed for an average of 2.5 years. We found that Medicare use increased in 1989 and the risk of transiting from Medicare to self-pay decreased compared to 1988. Spend-down from self-pay to Medicaid was 60% more likely in 1990. The MCCA clearly increased access to Medicare coverage of nursing home care among individuals previously paying privately.

Aged↗
PubMed1996

Who needs antiplatelet therapy?

A series of overviews or meta-analyses of randomized clinical trials prepared by the Antiplatelet Trialists' Collaboration were published in the British Medical Journal in January 1994. They demonstrated that prolonged courses of medium-dose aspirin were very effective at preventing both fatal and non-fatal myocardial infarction and stroke in patients at high risk of occlusive vascular disease. The aim of this review is to provide the general practitioner with a practical guide to the use of aspirin in patients at high and low risk of occlusive vascular disease and to discuss appropriate dosages and contraindications to treatment in the light of all the recent evidence.

Aspirin↗
PubMed1995

Randomised trial of lipid lowering dietary advice in general practice: the effects on serum lipids, lipoproteins, and antioxidants.

OBJECTIVE: To determine the relative efficacy in general practice of dietary advice given by a dietitian, a practice nurse, or a diet leaflet alone in reducing total and low density lipoprotein cholesterol concentration. DESIGN: Randomised six month parallel trial. SETTING: A general practice in Oxfordshire. SUBJECTS: 2004 subjects aged 35-64 years were screened for hypercholesterolaemia; 163 men and 146 women with a repeat total cholesterol concentration of 6.0-8.5 mmol/l entered the trial. INTERVENTIONS: Individual advice provided by a dietitian using a diet history, a practice nurse using a structured food frequency questionnaire, or a detailed diet leaflet sent by post. All three groups were advised to limit the energy provided by fat to 30% or less and to increase carbohydrate and dietary fibre. MAIN OUTCOME MEASURES: Concentrations of total cholesterol and low density and high density lipoprotein cholesterol after six months; antioxidant concentration and body mass index. RESULTS: No significant differences were found at the end of the trial between groups in mean concentrations of lipids, lipoproteins, and antioxidants or body mass index. After data were pooled from the three groups, the mean total cholesterol concentration fell by 1.9% (0.13 mmol/l, 95% confidence interval 0.06 to 0.22, P < 0.001) to 7.00 mmol/l, and low density lipoprotein cholesterol also fell. The total carotenoid concentration increased by 53 nmol/l (95% confidence interval 3.0 to 103, P = 0.039). CONCLUSIONS: Dietary advice is equally effective when given by a dietitian, a practice nurse, or a diet leaflet alone but results in only a small reduction in total and low density lipoprotein cholesterol. To obtain a better response more intensive intervention than is normally available in primary care is probably necessary.

Antioxidants↗
PubMed1995

The prevalence of a family history of cancer in general practice.

The presence of a family history of cancer of the colorectum, breast, uterus and ovary is associated with an increased risk for that type of cancer. The aim of this study was to assess the prevalence of a family history of these cancers in the community. Nurses asked all attenders at health checks aged 35-64 about the presence of a history in close relatives of cancer diagnosed under the age of 70. Information was obtained from 8109 patients. Of the sample, 3.1% had a family history of colorectal cancer; 4.8% of women had a family history of breast cancer, whilst 1.9% had a family history of uterine or ovarian cancer. Projecting the results to a population of 2000 demonstrated that a general practitioner with a list size of 2000 could expect to have 30-40 patients in whom an appropriate management strategy would need to be considered.

Adult↗
PubMed1995

Hormone replacement therapy: characteristics of users and non-users in a British general practice cohort identified through computerised prescribing records.

STUDY OBJECTIVE: To assess the feasibility of recruiting a cohort of women, including long term users of postmenopausal hormone replacement therapy (HRT), through computerised general practice prescribing records, and to compare clinical and demographic characteristics of users and non-user controls. DESIGN: Cross sectional analysis of questionnaire data. SETTING: Subjects were recruited through 17 general practices in the Oxfordshire, south west Thames, and north west Thames regions that contributed to the VAMP Research Database. PARTICIPANTS: A total of 2964 women aged 45-64 years were identified. Altogether 1482 were long term (> 1 year) users of HRT and 1482 were non-user controls: 1037 (70%) of the users and 819 (55.3%) of the controls agreed to participate and provided questionnaire data. MAIN RESULTS: Users of HRT were more likely to have undergone hysterectomy than controls. Most women with a history of hysterectomy used unopposed oestrogen, while those with intact uteri generally used a combination of oestrogen and a progestagen. Among women who had undergone hysterectomy, HRT users did not differ significantly from controls over a range of demographic and clinical characteristics but they were more likely to be past users of oral contraceptives. Among women with intact uteri, users were similar to controls in terms of reported clinical characteristics, but were of higher social class and were more likely to be past users of oral contraceptives and to have had a mammogram after the age of 50. Compared with the general population, all categories of women recruited to the study were of higher social class and exhibited more health conscious behaviours. CONCLUSIONS: Electronic general practice prescribing records provide a feasible and efficient method for recruiting women to a cohort of HRT. Women who agreed to participate in this study were not representative of the general population, emphasising the importance of internal controls in such a study. Among participants, HRT users who had not undergone hysterectomy showed evidence of better health than non-users on some dimensions. In the whole sample, however, there were no appreciable differences in social class and self reported health indicators between users and controls.

Cohort Studies↗
PubMed1995

The Cochrane Collaboration in Primary Care: an international resource for evidence-based practice of family medicine.

In recent years, promoting the use of evidence-based decision making in health care has been gaining popularity. This method of decision making requires that the results of primary research be compiled in a systematic manner and made accessible to those involved in the decision-making process. Failure to do this may result in a considerable lag period before therapies of proven effectiveness are implemented in medical practice or ineffective therapies are withdrawn from practice. The Cochrane Collaboration in Primary Health Care was established as part of an international effort to facilitate the preparation, maintenance, and dissemination of systematic reviews of the effects of health care provided in, or relevant to family practice. This paper describes the progress made in establishing the Cochrane Collaboration as an international register of randomized controlled trials in family medicine that will subsequently be used for undertaking systematic reviews in the discipline.

Clinical Trials as Topic↗
PubMed1995

Primary care management of acute herpes zoster: systematic review of evidence from randomized controlled trials.

Although a number of randomized controlled trials of treatment for herpes zoster have been performed, there is no consensus on how it should be managed in general practice. A systematic review of existing trials, including meta-analysis, was performed to determine the efficacy of available therapies in reducing the incidence of postherpetic neuralgia. The treatments studied included antiviral agents, corticosteroids and other drugs which had been studied in randomized trials. Trials were included if the subjects were immunocompetent adults and the intervention was feasible in general practice. The main outcome measure was prevalence of pain at one, three and six months after onset of the acute herpetic rash. Data for each time point were not available for all trials. The quality of studies was also assessed. Pooled analyses of trials with acyclovir failed to detect a significant reduction of pain in the treatment group at one or six months, but found a 35% reduction at three months. Confidence limits were wide, and a modest benefit of treatment cannot be ruled out at one and six months. Pooled analyses were not possible for other treatments, either because too few trials had been performed, or because completed trials demonstrated significant heterogeneity. Many clinical trials in this area have been too small to give reliable results. Variations in the definition and reporting of postherpetic neuralgia create difficulties in combining data from different studies. Firm recommendations for clinical practice are not possible because existing evidence neither confirms nor refutes the hypothesis that treatment during the acute phase of herpes zoster reduces pain later.

Acute Disease↗
PubMed1995

The detection and management of hypertension in the elderly of Northamptonshire.

BACKGROUND: The aim of this study was to apply recommendations from randomized controlled trials and guidelines on the detection and control of hypertension in the elderly to a district health authority population. METHODS: A cross-sectional audit of Northamptonshire general practitioners' (GPs') records from February to June 1993 was carried out. RESULTS: A total of 2428 notes of men and women aged 65 or over registered with their GP was audited. A large proportion of patients, 86 per cent (95 per cent CI 84.6-87.4 per cent), had a blood pressure record taken in the last 10 years. Of those with raised blood pressure (BP > or = 160/90 mmHg) 49 per cent (95 per cent CI 46.2-51.8 per cent) were untreated, and 58 per cent (95 per cent CI 54-61.9 per cent) of those labelled as hypertensive were not adequately controlled. The prevalence of labelled hypertension was 25 per cent (95 per cent CI 23.3-26.7 per cent). CONCLUSIONS: From these results it is estimated that between 11 and 29 fatal and non-fatal strokes could be prevented in the 65-74-year-old age population of Northamptonshire each year if current guidelines were followed. Improved detection and management of elderly hypertensive patients in primary care could contribute significantly towards the target for stroke reduction set in the Health of the nation strategy.

Aged↗