PubMed Health⌕ Search

Biomedical subjects

J Martin Bland

Publications and source records attributed to J Martin Bland.

13 recordsLinked to original sources

Restenosis after carotid angioplasty, stenting, or endarterectomy in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS).

BACKGROUND AND PURPOSE: Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS) patients with carotid stenosis were randomized between endovascular treatment and endarterectomy. The rates of residual severe stenosis and restenosis and their contribution to recurrent symptoms was unclear. METHODS: Endovascular patients were treated by balloon angioplasty alone (88%) or stenting (22%). Patches were used in 63% of endarterectomy patients. Carotid stenosis was categorized as mild (0% to 49%), moderate (50% to 69%), severe (70% to 99%), or occluded, using standardized Doppler ultrasound criteria at the examination closest to 1 month (n=283) and 1 year (n=347) after treatment. Recurrent cerebrovascular symptoms during follow-up were analyzed. RESULTS: More patients had > or =70% stenosis of the ipsilateral carotid artery 1 year after endovascular treatment than after endarterectomy (18.5% versus 5.2%, P=0.0001). Residual severe stenosis was present in 6.5% of patients at 1 month after endovascular treatment. Between 1 month and 1 year, restenosis to > or =70% stenosis occurred in 10.5% of the endovascular group. After endarterectomy, 1.7% had residual severe stenosis at 1 month, and 2.5% developed severe restenosis. The results were significantly better after stenting compared with angioplasty alone at 1 month (P<0.001) but not at 1 year. Recurrent ipsilateral symptoms were more common in endovascular patients with severe stenosis (5/32 [15.6%]) compared with lesser degrees of stenosis at 1 year (11/141 [7.8%], P=0.02), but most were transient ischemic attacks and none were disabling or fatal strokes. There were no recurrent symptoms in the 9 endarterectomy patients with > or =70% stenosis at 1 year. CONCLUSIONS: Carotid stenosis 1 year after endovascular treatment is partly explained by poor initial anatomical results and partly by restenosis. The majority of patients were treated by angioplasty without stenting. Further randomized studies are required to determine whether newer carotid stenting techniques are associated with a lower risk of restenosis. The low rate of recurrent stroke in both endovascular and endarterectomy patients suggests that treatment of restenosis should be limited to patients with recurrent symptoms, but long term follow up data are required.

Angioplasty, Balloon↗

Bronchodilator treatment and deaths from asthma: case-control study.

OBJECTIVE: To investigate the association between bronchodilator treatment and death from asthma. DESIGN: Case-control study. SETTING: 33 health authorities or health boards in Great Britain. PARTICIPANTS: 532 patients under age 65 who died from asthma and 532 controls with a hospital admission for asthma matched for period, age, and area. MAIN OUTCOME MEASURES: Odds ratios for deaths from asthma associated with prescription of bronchodilators and other treatment, with sensitivity analyses adjusting for age at onset, previous hospital admissions, associated chronic obstructive lung disease, and number of other drug categories. RESULTS: After full adjustment, there were no significant associations with drugs prescribed in the 4-12 months before the index date. For prescriptions in the 1-5 years before, mortality was positively associated with inhaled short acting beta2 agonists (odds ratio 2.05, 95% confidence interval 1.26 to 3.33) and inversely associated with antibiotics (0.59, 0.39 to 0.89). The former association seemed to be confined to those aged 45-64, and the association with antibiotics was more pronounced in those under 45. Significant age interactions across all periods suggested inverse associations with oral steroids confined to the under 45 age group. An inverse association with long acting beta2 agonists and a positive association with methylxanthines in the 1-5 year period were non-significant. CONCLUSION: There was no evidence of adverse effects on mortality with medium to long term use of inhaled long acting beta2 agonist drugs. The association with short acting beta(2) agonists has several explanations, only one of which may be a direct adverse effect.

Adolescent↗

Teaching statistics to medical students using problem-based learning: the Australian experience.

BACKGROUND: Problem-based learning (PBL) is gaining popularity as a teaching method in UK medical schools, but statistics and research methods are not being included in this teaching. There are great disadvantages in omitting statistics and research methods from the main teaching. PBL is well established in Australian medical schools. The Australian experience in teaching statistics and research methods in curricula based on problem-based learning may provide guidance for other countries, such as the UK, where this method is being introduced. METHODS: All Australian medical schools using PBL were visited, with two exceptions. Teachers of statistics and medical education specialists were interviewed. For schools which were not visited, information was obtained by email. RESULTS: No Australian medical school taught statistics and research methods in a totally integrated way, as part of general PBL teaching. In some schools, statistical material was integrated but taught separately, using different tutors. In one school, PBL was used only for 'public health' related subjects. In some, a parallel course using more traditional techniques was given alongside the PBL teaching of other material. This model was less successful than the others. CONCLUSIONS: There are several difficulties in implementing an integrated approach. However, not integrating is detrimental to statistics and research methods teaching, which is of particular concern in the age of evidence-based medicine. Some possible ways forward are suggested.

Australia↗

Cluster randomised trials in the medical literature: two bibliometric surveys.

BACKGROUND: Several reviews of published cluster randomised trials have reported that about half did not take clustering into account in the analysis, which was thus incorrect and potentially misleading. In this paper I ask whether cluster randomised trials are increasing in both number and quality of reporting. METHODS: Computer search for papers on cluster randomised trials since 1980, hand search of trial reports published in selected volumes of the British Medical Journal over 20 years. RESULTS: There has been a large increase in the numbers of methodological papers and of trial reports using the term 'cluster random' in recent years, with about equal numbers of each type of paper. The British Medical Journal contained more such reports than any other journal. In this journal there was a corresponding increase over time in the number of trials where subjects were randomised in clusters. In 2003 all reports showed awareness of the need to allow for clustering in the analysis. In 1993 and before clustering was ignored in most such trials. CONCLUSION: Cluster trials are becoming more frequent and reporting is of higher quality. Perhaps statistician pressure works.

Bias↗

The logrank test.

Explore the source record for details and available documents.

Astrocytoma↗

Use of serial maternal urine cytomegalovirus PCR to detect primary CMV infection in seronegative pregnant women.

The aim of the study was to determine if serial maternal urine polymerase chain reaction (PCR) tests can detect primary CMV infection during pregnancy. This was a prospective study conducted from 1 January 1999 to 31 December 1999 in an antenatal clinic setting of a teaching hospital. The study group included women who were CMV IgG negative and aged <30 years or had a pre-school child. They were invited to self-collect urine samples monthly and send them to the laboratory by post. Cord bloods were tested for CMV IgG to detect seroconversion. An anxiety questionnaire was sent to all study participants. At first attendance, 1549 (42%) women were CMV IgG negative. Of the 696 eligible women, 609 (88%) participated in the urine PCR study. PCR was performed on 2263 urine samples (median of 4/pregnancy). Primary CMV infection was identified in one woman by urine PCR at 36 weeks (baby CMV negative). Cord blood samples were available from 152/609 infants (25%). Seroconversion was noted in only one woman. Replies to the questionnaire were received from 264/609 women (43%): 214 (81%) had little or no anxiety, and 220 (83%) felt reassured by their study participation. Serial urine PCR is a feasible method of detecting primary maternal CMV infection during pregnancy which has potential for evaluation in further studies.

Adolescent↗

Rheumatic disease differentiation using immunoglobulin G sugar printing by high density electrophoresis.

OBJECTIVE: To determine whether immunoglobulin G (IgG) sugar printing using high density electrophoresis can be a diagnostic and prognostic test to rapidly differentiate early rheumatoid arthritis (ERA), rheumatoid arthritis (RA), and other rheumatic diseases from each other. METHODS: One hundred fifty-three patients with ERA/RA, psoriatic arthritis (PsA), early psoriatic arthritis (EPsA) ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), juvenile idiopathic arthritis (JIA), early undifferentiated seronegative arthritis (UA), and osteoarthritis (OA) were investigated. Samples of their serum IgG were purified, and sugars were released enzymatically and fluorophore-labelled, then subjected to high density electrophoresis, and relative quantities of each sugar were determined by optical density. RESULTS: Sugar prints of 9 sugars were compiled for each of the 9 disease groups. Specific disease-associated sugar changes were determined by comparison with OA. For example, agalactosylated structures were increased in ERA/RA and EPsA/PsA (p = 0.0001-0.004) and digalactosylated structures were decreased in PsA, AS, and JIA (p = 0.0001-0.04). When the disease groups were compared, each disease was characterized by a unique sugar print comprising 7 of the 9 sugars (p = 0.001-0.005); only g0fb and a1f were not associated. ERA/RA differed in the quantities of monogalactosyl and sialylated sugars (p = 0.006-0.007). The presence of agalactosyl sugars enabled correct prediction of RA in 71.2% of individuals, with a specificity of 84.2% and sensitivity of 50.0%. The area under the sensitivity versus specificity curve was 0.7812. CONCLUSION: IgG sugar printing was found to be effective in differentiation of rheumatic diseases and can differentiate ERA and RA from each other and from other rheumatic diseases; and hence may constitute a relatively rapid diagnostic and prognostic test for patients presenting with arthritis.

Adult↗

A longitudinal assessment of thyroid hormone concentrations in preterm infants younger than 30 weeks' gestation during the first 2 weeks of life and their relationship to outcome.

OBJECTIVE: This trial examined the effects of triiodothyronine (T3) and hydrocortisone on lung disease. We present here the placebo data as this provides a natural history of thyroid hormone changes in this group of very preterm infants. We also examined the relationship between thyroid hormone levels and the outcome death and ventilator dependence at 2 weeks. METHODS: Plasma-free T3 (FT3), free thyroxine (FT4), total T3, total T4, and thyroid-stimulating hormone were measured prospectively in preterm infants who were <30 weeks' gestation during the first 14 days of life. The data were obtained from the placebo arm of a multicenter, randomized, double-blind, clinical trial of T3 and hydrocortisone, called the THORN Trial. RESULTS: A total of 128 infants were recruited into the placebo group. The mean FT3 level at <5 hours of age was 4.9 pmol/L and remained below this level. FT4 levels decreased from 15 pmol/L to 9.7 pmol/L at 7 days and then increased to 11.0 pmol/L by day 14. Total T3 and total T4 levels fell after 5 hours of age and reached a minimum on day 3. Thyroid-stimulating hormone levels fell markedly from 9.2 mU/L to 1.8 mU/L at 72 hours and then increased to approximately 4 mU/L. We found that all thyroid hormones but particularly FT3 and FT4 hormones were highly significantly related to outcome. The lower the hormone levels, the worse the outcome (death or ventilator dependence at 2 weeks of age). CONCLUSION: 1) Thyroid hormone levels in preterm infants <30 weeks were much lower than in term infants, 2) the postnatal surge of thyroid hormones normally seen at 24 to 48 hours of age in term infants did not occur in our group of preterm infant, and 3) low FT3 and FT4 levels are associated with higher mortality and severity of lung disease.

Age Factors↗