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1.
ObjectiveTo evaluate the performance of a near patient test for Helicobacter pylori infection in primary care.DesignValidation study performed within a randomised trial of four management strategies for dyspepsia.Setting43 general practices around Nottingham.Subjects394 patients aged 18-70 years presenting with recent onset dyspepsia.ResultsWhen used in primary care FlexSure test had a sensitivity and specificity of 67% (95% confidence interval 59% to 75%) and 98% (95% to 99%) compared with a sensitivity and specificity of 92% (87% to 97%) and 90% (83% to 97%) when used previously in secondary care. Of the H pylori test and refer group 14% (28/199) were found to have conditions for which H pylori eradication was appropriate compared with 23% (39/170) of the group referred directly for endoscopy.ConclusionsWhen used in primary care the sensitivity of the FlexSure test was significantly poorer than in secondary care. About a third of patients who would have benefited from H pylori eradication were not detected. Near patient tests need to be validated in primary care before they are incorporated into management policies for dyspepsia.

Key messages

  • Near patient tests for H pylori infection have been recommended in the management of dyspepsia in primary care without proper evaluation
  • Such tests should have a high sensitivity to avoid missing treatable illness related to infection
  • The FlexSure near patient test had a lower sensitivity than previously reported in validation studies performed in secondary care
  • Fewer than expected numbers of patients with H pylori related pathology were identified with the FlexSure in primary care
  相似文献   

2.
3.
ObjectivesTo examine the frequency and quality of reporting on quality of life in randomised controlled trials.DesignSearch of the Cochrane Controlled Trials Register 1980 to 1997 to identify trials from all disciplines, from oncology, and from cardiovascular medicine that reported on quality of life. Assessment of abstracts from articles published from 1993 to 1996. Assessment of a sample of full reports with a standardised instrument.ResultsDuring 1980-97 reporting on quality of life increased from 0.63% to 4.2% for trials from all disciplines, from 1.5% to 8.2% for cancer trials, and from 0.34% to 3.6% for cardiovascular trials. Of 364 abstracts, 65% reported on drug interventions. Of a sample of 67 full reports, authors of 48 (72%) used 62 established quality of life instruments. In 15 reports (22%) authors developed their own measures, and in 2 (3%) methods were unclear. Response rates were given in 38 (57%), and complete reporting on all items and scales occurred in 31 (46%).ConclusionsLess than 5% of all randomised controlled trials reported on quality of life, and this proportion was below 10% even for cancer trials. A plethora of instruments was used in different studies, and the reporting of methods and results was often inadequate. Standards for the measurement and reporting of quality of life in clinical trials research need to be developed.

Key messages

  • We examined the reporting on quality of life in randomised controlled trials listed in the Cochrane Controlled Trials Register
  • Although reporting on quality of life increased over time, fewer than 5% of trials overall and fewer than 10% of cancer trials included quality of life in 1997
  • Among 67 articles selected at random for detailed examination, a wide range of established and self developed measures of quality of life were used
  • Only about half of trials gave response rates, and less than half reported on all items and scales used
  • Standards for assessing and reporting quality of life in clinical research trials need to be developed
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4.
ObjectiveTo evaluate the efficacy of using a nicotine patch for 5 months with a nicotine nasal spray for 1 year.DesignPlacebo controlled, double blind trial.SettingReykjavik health centre.Subjects237 smokers aged 22-66 years living in or around Reykjavik.InterventionsNicotine patch for 5 months with nicotine nasal spray for 1 year (n=118) or nicotine patch with placebo spray (n=119). Treatment with patches included 15 mg of nicotine for 3 months, 10 mg for the fourth month, and 5 mg for the fifth month, whereas nicotine in the nasal spray was available for up to 1 year. Both groups received supportive treatment.ResultsThe log rank test for 6 years (χ2=8.5, P=0.004) shows a significant association between abstinence from smoking and type of treatment. Sustained abstinence rates for the patch and nasal spray group and patch only group were 51% v 35% after 6 weeks (P=0.011 (χ2), 95% confidence interval 1.17% to 3.32%), 37% v 25% after 3 months (P=0.045, 1.01% to 3.08%), 31% v 16% after 6 months (P=0.005, 1.27% to 4.50%), 27% v 11% after 12 months (P=0.001, 1.50% to 6.14%), and 16% v 9% after 6 years (P=0.077, 0.93% to 4.72%).ConclusionsShort and long term abstinence rates show that the combination of using a nicotine patch for 5 months with a nicotine nasal spray for 1 year is a more effective method of stopping smoking than using a patch only. The low percentage of participants using the nasal spray at 1 year, and the few relapses during the second year, suggest that it is not cost effective to use a nasal spray for longer than 7 months after stopping a patch.

Key messages

  • Combined methods of nicotine replacement therapy have a potential advantage over one method because of high levels of substitution
  • Nicotine patches release nicotine slowly, but nicotine nasal spray delivers nicotine more rapidly, enabling the smoker to respond quickly to any smoking urges
  • Treatment with a patch and nicotine nasal spray was significantly more effective than patch and placebo from day 15 after stopping smoking
  • Using a patch for 5 months with a nicotine nasal spray for 1 year provides a more effective means of stopping smoking than using a patch only
  • It is not cost effective to use a nicotine nasal spray for longer than 7 months after stopping a patch
  相似文献   

5.
ObjectivesTo assess the methodological quality of intention to treat analysis as reported in randomised controlled trials in four large medical journals.DesignSurvey of all reports of randomised controlled trials published in 1997 in the BMJ, Lancet, JAMA, and New England Journal of Medicine.Results119 (48%) of the reports mentioned intention to treat analysis. Of these, 12 excluded any patients who did not start the allocated intervention and three did not analyse all randomised subjects as allocated. Five reports explicitly stated that there were no deviations from random allocation. The remaining 99 reports seemed to analyse according to random allocation, but only 34 of these explicitly stated this. 89 (75%) trials had some missing data on the primary outcome variable. The methods used to deal with this were generally inadequate, potentially leading to a biased treatment effect. 29 (24%) trials had more than 10% of responses missing for the primary outcome, the methods of handling the missing responses were similar in this subset.ConclusionsThe intention to treat approach is often inadequately described and inadequately applied. Authors should explicitly describe the handling of deviations from randomised allocation and missing responses and discuss the potential effect of any missing response. Readers should critically assess the validity of reported intention to treat analyses.

Key messages

  • Intention to treat gives a pragmatic estimate of the benefit of a change in treatment policy rather than of potential benefit in patients who receive treatment exactly as planned
  • Full application of intention to treat is possible only when complete outcome data are available for all randomised subjects
  • About half of all published reports of randomised controlled trials stated that intention to treat was used, but handling of deviations from randomised allocation varied widely
  • Many trials had some missing data on the primary outcome variable, and methods used to deal with this were generally inadequate, potentially leading to bias
  • Intention to treat analyses are often inadequately described and inadequately applied
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6.
ObjectivesTo identify which children with acute otitis media are at risk of poor outcome and to assess benefit from antibiotics in these children.DesignSecondary analysis of randomised controlled trial cohort.SettingPrimary care.Participants315 children aged 6 months to 10 years.InterventionImmediate or delayed (taken after 72 hours if necessary) antibiotics.ResultsDistress by day three was more likely in children with high temperature (adjusted odds ratio 4.5, 95% confidence interval 2.3 to 9.0), vomiting (2.6,1.3 to 5.0), and cough (2.0, 1.1 to 3.8) on day one. Night disturbance by day three was more likely with high temperature 2.4 (1.2 to 4.8), vomiting (2.1,1.1 to 4.0), cough (2.3,1.3 to 4.2), and ear discharge (2.1, 1.2 to 3.9). Among the children with high temperature or vomiting, distress by day three was less likely with immediate antibiotics (32% for immediate v 53% for delayed, χ2=4.0; P=0.045, number needed to treat 5) as was night disturbance (26% v 59%, χ2=9.3; P=0.002; number needed to treat 3). In children without higher temperature or vomiting, immediate antibiotics made little difference to distress by day three (15% v 19%, χ2=0.74; P=0.39) or night disturbance (20% v 27%, χ2=1.6; P=0.20). Addition of cough did not significantly improve prediction of benefit.ConclusionIn children with otitis media but without fever and vomiting antibiotic treatment has little benefit and a poor outcome is unlikely.

What is already known on this topic

Most children with otitis media will not benefit symptomatically from immediate use of antibioticsIt is unclear which children are more likely to benefit from antibiotics and which features predict poor outcome

What this study adds

Children with high temperature or vomiting were more likely to be distressed or have night disturbance three days after seeing the doctorChildren with high temperature or vomiting were more likely to benefit from antibiotics, although it is still reasonable to wait 24-48 hours as many children will settle anywayChildren without high temperature or vomiting were unlikely to have poor outcome and unlikely to benefit from immediate antibiotics  相似文献   

7.
Objective: To evaluate the READER model for critical reading by comparing it with a free appraisal, and to explore what factors influence different components of the model. Design: A randomised controlled trial in which two groups of general practitioners assessed three papers from the general practice section of the BMJ. Setting: Northern Ireland. Subjects: 243 general practitioners. Main outcome measures: Scores given using the READER model (Relevance, Education, Applicability, Discrimination, overall Evaluation) and scores given using a free appraisal for scientific quality and an overall total. Results: The hierarchical order for the three papers was different for the two groups, according to the total scores. Participants using the READER method (intervention group) gave a significantly lower total score (P⩽0.01) and a lower score for the scientific quality (P⩽0.0001) for all three papers. Overall more than one in five (22%), and more men than women, read more than 5 articles a month (P⩽0.05). Those who were trainers tended to read more articles (P⩽0.05), and no trainers admitted to reading none. Overall, 58% (135/234) (68% (76/112) of the intervention group) believed that taking part in the exercise would encourage them to be more critical of published articles in the future (P⩽0.01). Conclusion: Participants using the READER model gave a consistently lower overall score and applied a more appropriate appraisal to the methodology of the studies. The method was both accurate and repeatable. No intrinsic factors influenced the scores, so the model is appropriate for use by all general practitioners regardless of their seniority, location, teaching or training experience, and the number of articles they read regularly.

Key messages

  • The READER method of critical appraisal is simple and easy to apply
  • The method is accurate and repeatable
  • General practitioners using a structured appraisal are more critical of quality
  • The model may be used by general practitioners with different backgrounds, seniority, and experience of teaching and training
  相似文献   

8.
ObjectiveTo estimate and interpret time trends in vertical transmission rates for HIV using data from national obstetric and paediatric surveillance registers.DesignProspective study of HIV infected women reported through obstetric surveillance. HIV infection status of the child and onset of AIDS were reported through paediatric surveillance. Rates of vertical transmission and progression to AIDS rate were estimated by methods that take account of incomplete follow up of children with indeterminate infection status and delay in AIDS reporting.SettingBritish Isles.SubjectsPregnant women infected with HIV whose infection was diagnosed before delivery, and their babies.ResultsBy January 1999, 800 children born to diagnosed HIV infected women who had not breast fed had been reported. Vertical transmission rates rose to 19.6% (95% confidence interval 8.0% to 32.5%) in 1993 before falling to 2.2% (0% to 7.8%) in 1998. Between 1995 and 1998 use of antiretroviral treatment increased significantly each year, reaching 97% of live births in 1998. The rate of elective caesarean section remained constant, at around 40%, up to 1997 but increased to 62% in 1998. Caesarean section and antiretroviral treatment together were estimated to reduce risk of transmission from 31.6% (13.6% to 52.2%) to 4.2% (0.8% to 8.5%). The proportion of infected children developing AIDS in the first 6 months fell from 17.7% (6.8% to 30.8%) before 1994 to 7.2% (0% to 15.7%) after, coinciding with increased use of prophylaxis against Pneumocystis carinii pneumonia.ConclusionsIn the British Isles both HIV related morbidity and vertical transmission are being reduced through increased use of interventions.

Key messages

  • Reliable estimates of HIV vertical transmission rates can be derived from surveillance data
  • Infected pregnant women are increasingly taking up elective caesarean section and antiretroviral treatment to reduce the risk of transmitting HIV to their babies
  • Vertical transmission rates have fallen greatly over the past four years and progression to AIDS among infected children may also have slowed
  • These benefits can occur only if infected women are diagnosed before or during pregnancy
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9.
ObjectiveTo evaluate the influence of preoperative abstinence on postoperative outcome in alcohol misusers with no symptoms who were drinking the equivalent of at least 60 g ethanol/day. DesignRandomised controlled trial.SettingCopenhagen, Denmark.Subjects42 alcoholic patients without liver disease admitted for elective colorectal surgery.InterventionsWithdrawal from alcohol consumption for 1 month before operation (disulfiram controlled) compared with continuous drinking.ResultsThe intervention group developed significantly fewer postoperative complications than the continuous drinkers (31% v 74%, P=0.02). Delayed type hypersensitivity responses were better in the intervention group before (37 mm2 v 12 mm2, P=0.04), but not after surgery (3 mm2 v 3 mm2). Development of postoperative myocardial ischaemia (23% v 85%) and arrhythmias (33% v 86%) on the second postoperative day as well as nightly hypoxaemic episodes (4 v 18 on the second postoperative night) occurred significantly less often in the intervention group. Surgical stress responses were lower in the intervention group (P⩽0.05).ConclusionsOne month of preoperative abstinence reduces postoperative morbidity in alcohol abusers. The mechanism is probably reduced preclinical organ dysfunction and reduction of the exaggerated response to surgical stress.

Key messages

  • Recent data have shown alcohol misusers to have a threefold increase in postoperative morbidity
  • In misusers recovery from organ dysfunction induced by alcohol is seen after abstinence
  • Abstinence from alcohol for 1 month before surgery reduces postoperative morbidity after colorectal surgery
  • Mechanisms may involve reduced responses to surgical stress and improved cardiac and immune dysfunction
  • Withdrawal from alcohol before an operation is recommended in alcohol abusers
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10.
ObjectivesTo assess the effectiveness of β blockers in short term treatment for acute myocardial infarction and in longer term secondary prevention; to examine predictive factors that may influence outcome and therefore choice of drug; and to examine the clinical importance of the results in the light of current treatment.DesignSystematic review of randomised controlled trials.SettingRandomised controlled trials.SubjectsPatients with acute or past myocardial infarction.Interventionβ Blockers compared with control.Mainoutcome measures All cause mortality and non-fatal reinfarction.ResultsOverall, 5477 of 54 234 patients (10.1%) randomised to β blockers or control died. We identified a 23% reduction in the odds of death in long term trials (95% confidence interval 15% to 31%), but only a 4% reduction in the odds of death in short term trials (−8% to 15%). Meta regression in long term trials did not identify a significant reduction in effectiveness in drugs with cardioselectivity but did identify a near significant trend towards decreased benefit in drugs with intrinsic sympathomimetic activity. Most evidence is available for propranolol, timolol, and metoprolol. In long term trials, the number needed to treat for 2 years to avoid a death is 42, which compares favourably with other treatments for patients with acute or past myocardial infarction.Conclusionsβ Blockers are effective in long term secondary prevention after myocardial infarction, but they are underused in such cases and lead to avoidable mortality and morbidity.

Key messages

  • The first randomised trials of β blockade in secondary prevention after myocardial infarction were published in the 1960s
  • β blockers were once heralded as a major advance, but their use for secondary prevention has declined in recent years
  • Firm evidence shows that long term β blockade remains an effective and well tolerated treatment that reduces mortality and morbidity in unselected patients after myocardial infarction
  • The benefits from β blockade compare favourably with other drug treatments for this patient group
  • Most evidence is for propranolol, timolol, and metoprolol, whereas atenolol, which is commonly used, is inadequately evaluated for long term use
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11.
ObjectivesTo identify the number and current location of children, aged 0 to 16 years, requiring long term ventilation in the United Kingdom, and to establish their underlying diagnoses and ventilatory needs.DesignPostal questionnaires sent to consultant respiratory paediatricians and all lead clinicians of intensive care and special care baby units in the United Kingdom.SubjectsAll children in the United Kingdom who, when medically stable, continue to need a mechanical aid for breathing.Results141 children requiring long term ventilation were identified from the initial questionnaire. Detailed information was then obtained on 136 children from 30 units. Thirty three children (24%) required continuous positive pressure ventilation by tracheostomy over 24 hours, and 103 received ventilation when asleep by a non-invasive mask (n=62; 46%), tracheostomy (n=32; 24%), or negative pressure ventilation (n=9; 7%). Underlying conditions included neuromuscular disease (n=62; 46%), congenital central hypoventilation syndrome (n=18; 13%), spinal injury (n=16; 12%), craniofacial syndromes (n=9; 7%), bronchopulmonary dysplasia (n=6; 4%), and others (n=25; 18%). 93 children were cared for at home. 43 children remained in hospital because of home circumstances, inadequate funding, or lack of provision of home carers. 96 children were of school age and 43 were attending mainstream school.ConclusionsA significant increase in the number of children requiring long term ventilation in the United Kingdom has occurred over the past decade. Contributing factors include improved technology, developments in paediatric non-invasive ventilatory support, and a change in attitude towards home care. Successful discharge home and return to school is occurring even for severely disabled patients. Funding and home carers are common obstacles to discharge.

Key messages

  • The number of children requiring long term ventilatory support has increased substantially in the past 8 years
  • Ventilatory support at home is the best option for meeting the child’s psychological needs and enhancing quality of life
  • The majority of children dependent on long term ventilation live at home and attend mainstream schools
  • A shift of care has occurred from intensive care units to less acute areas
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12.
Objective: To determine the size of reduction in homocysteine concentrations produced by dietary supplementation with folic acid and with vitamins B-12 or B-6. Design: Meta-analysis of randomised controlled trials that assessed the effects of folic acid based supplements on blood homocysteine concentrations. Multivariate regression analysis was used to determine the effects on homocysteine concentrations of different doses of folic acid and of the addition of vitamin B-12 or B-6. Subjects: Individual data on 1114 people included in 12 trials. Findings: The proportional and absolute reductions in blood homocysteine produced by folic acid supplements were greater at higher pretreatment blood homocysteine concentrations (P<0.001) and at lower pretreatment blood folate concentrations (P<0.001). After standardisation to pretreatment blood concentrations of homocysteine of 12 μmol/l and of folate of 12 nmol/l (approximate average concentrations for Western populations), dietary folic acid reduced blood homocysteine concentrations by 25% (95% confidence interval 23% to 28%; P<0.001), with similar effects in the range of 0.5-5 mg folic acid daily. Vitamin B-12 (mean 0.5 mg daily) produced an additional 7% (3% to 10%) reduction in blood homocysteine. Vitamin B-6 (mean 16.5 mg daily) did not have a significant additional effect. Conclusions: Typically in Western populations, daily supplementation with both 0.5-5 mg folic acid and about 0.5 mg vitamin B-12 would be expected to reduce blood homocysteine concentrations by about a quarter to a third (for example, from about 12 μmol/l to 8-9 μmol/l). Large scale randomised trials of such regimens in high risk populations are now needed to determine whether lowering blood homocysteine concentrations reduces the risk of vascular disease.

Key messages

  • Higher blood homocysteine concentrations seem to be associated with higher risks of occlusive vascular disease and with lower blood concentrations of folate and vitamins B-12 and B-6
  • Proportional and absolute reductions in blood homocysteine concentrations with folic acid supplements are greater at higher pretreatment blood homocysteine concentrations and at lower pretreatment blood folate concentrations
  • In typical Western populations, supplementation with both 0.5-5 mg daily folic acid and about 0.5 mg daily vitamin B-12 should reduce blood homocysteine concentrations by about a quarter to a third
  • Large scale randomised trials of such regimens in people at high risk are now needed to determine whether lowering blood homocysteine concentrations reduces the risk of vascular disease
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13.
ObjectiveTo compare the efficacy of non-invasive testing for Helicobacter pylori with that of endoscopy (plus H pylori testing) in the management of patients referred for endoscopic investigation of upper gastrointestinal symptoms.DesignRandomised controlled trial with follow up at 12 months.SettingHospital gastroenterology unit.Participants708 patients aged under 55 referred for endoscopic investigation of dyspepsia, randomised to non-invasive breath test for H pylori or endoscopy plus H pylori testing.ResultsIn 586 patients followed up at 12 months the mean change in dyspepsia score was 4.8 in the non-invasive H pylori test group and 4.6 in the endoscopy group (95% confidence interval for difference –0.7 to 0.5, P=0.69). Only 8.2% of patients followed up who were randomised to breath test alone were referred for subsequent endoscopy. The use of non-endoscopic resources was similar in the two groups. Reassurance value, concern about missed pathology, overall patient satisfaction, and quality of life were similar in the two groups. The patients found the non-invasive breath test procedure less uncomfortable and distressing than endoscopy with or without sedation. No potentially serious pathology requiring treatment other than eradication of H pylori was missed.ConclusionIn this patient group, non-invasive testing for H pylori is as effective and safe as endoscopy and less uncomfortable and distressing for the patient. Non-invasive H pylori testing should be the preferred mode of investigation.

What is already known on this topic

Endoscopy is a commonly used investigation for upper gastrointestinal symptoms, but its effectiveness has been questionedNon-invasive testing for Helicobacter pylori has been shown to predict endoscopic diagnosis in patients with dyspepsia

What this study adds

In patients less than 55 years of age with uncomplicated dyspepsia, non-invasive testing for H pylori is as effective and as safe as endoscopyNon-invasive H pylori testing is as reassuring to the patient as endoscopy and is less uncomfortable and distressing  相似文献   

14.
ObjectiveTo determine the prevalence of common mental disorders (anxiety and depression) and help seeking behaviour in African Caribbeans and white Europeans.DesignTwo phase survey in a general population sample. The first phase comprised screening with the 12 item general health questionnaire; the second phase was standardised psychiatric assessment and interview about help seeking.SettingPeople registered with four general practices in central Manchester.ParticipantsOf 1467 people randomly selected from family health services authority lists, 864 were still resident. 337 African Caribbeans and 275 white Europeans completed the screening phase (response rate 71%); 127 African Caribbeans and 103 white Europeans were interviewed in the second phase.Results13% of African Caribbeans (95% confidence interval 10% to 16%) and 14% (10% to 18%) of white Europeans had one or more disorder. Anxiety disorders were significantly less common among African Caribbeans (3% (1% to 5%) v 9% (6% to 12%) in white Europeans). Depressive disorders were significantly more common among African Caribbean women than white women (difference 8% (1% to 15%)). Medical help seeking was similar in the two groups, but African Caribbeans with mental disorders were more likely to seek additional help from non-medical sources (12/29 v 5/29, P=0.082).ConclusionsIn an inner city setting the prevalence of common mental disorders is similar in these two ethnic groups.

Key messages

  • Most studies of ethnic differences in mental health focus on psychotic illness rather than common mental disorders
  • In this inner city study the prevalence of anxiety and depression was similar in African Caribbeans and white Europeans
  • Anxiety disorders were less common, and depression more common, in African Caribbeans than white Europeans
  • Improved recognition and treatment of non-psychotic disorders are necessary, taking into account patients’ views of their illnesses
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15.

Background

Premature birth is the major cause of perinatal mortality and morbidity in both high- and low-income countries. The causes of preterm labour are multiple but infection is important. We have previously described an unusually high incidence of preterm birth (20%) in an ultrasound-dated, rural, pregnant population in Southern Malawi with high burdens of infective morbidity. We have now studied the impact of routine prophylaxis with azithromycin as directly observed, single-dose therapy at two gestational windows to try to decrease the incidence of preterm birth.

Methods and Findings

We randomized 2,297 pregnant women attending three rural and one peri-urban health centres in Southern Malawi to a placebo-controlled trial of oral azithromycin (1 g) given at 16–24 and 28–32 wk gestation. Gestational age was determined by ultrasound before 24 wk. Women and their infants were followed up until 6 wk post delivery. The primary outcome was incidence of preterm delivery, defined as <37 wk. Secondary outcomes were mean gestational age at delivery, perinatal mortality, birthweight, maternal malaria, and anaemia. Analysis was by intention to treat. There were no significant differences in outcome between the azithromycin group (n = 1,096) and the placebo group (n = 1,087) in respect of preterm birth (16.8% versus 17.4%), odds ratio (OR) 0.96, 95% confidence interval (0.76–1.21); mean gestational age at delivery (38.5 versus 38.4 weeks), mean difference 0.16 (−0.08 to 0.40); mean birthweight (3.03 versus 2.99 kg), mean difference 0.04 (−0.005 to 0.08); perinatal deaths (4.3% versus 5.0%), OR 0.85 (0.53–1.38); or maternal malarial parasitaemia (11.5% versus 10.1%), OR 1.11 (0.84–1.49) and anaemia (44.1% versus 41.3%) at 28–32 weeks, OR 1.07 (0.88–1.30). Meta-analysis of the primary outcome results with seven other studies of routine antibiotic prophylaxis in pregnancy (>6,200 pregnancies) shows no effect on preterm birth (relative risk 1.02, 95% confidence interval 0.86–1.22).

Conclusions

This study provides no support for the use of antibiotics as routine prophylaxis to prevent preterm birth in high risk populations; prevention of preterm birth requires alternative strategies.

Trial registration

Current Controlled Trials ISRCTN84023116 Please see later in the article for the Editors'' Summary  相似文献   

16.
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.

Key messages

  • Results from metabolic ward studies suggest that dietary change can reduce blood cholesterol concentrations by up to 15%
  • In free-living subjects the standard step 1 diet of the American Heart Association lowers cholesterol concentration by about 3%, and about another 3% can be achieved with more intensive diets
  • Difficulties in complying with the prescribed dietary change explain the failure to achieve the expected reductions in cholesterol concentrations
  • It is important to be realistic about the reductions in cardiovascular risk that can be achieved by individual dietary counselling
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17.
ObjectiveTo report the career choices and career destinations in 1995 of doctors who qualified in the United Kingdom in 1988.DesignPostal questionnaire.SettingUnited Kingdom.SubjectsAll doctors who qualified in the United Kingdom in 1988.ResultsOf the 3724 doctors who were sent questionnaires, eight had died and three declined to participate. Of the remaining 3713 doctors, 2885 (77.7%) replied. 16.9% (608/3593; 95% confidence interval 16.1% to 17.8%) of all 1988 qualifiers from medical schools in Great Britain were not working in the NHS in Great Britain in 1995 compared with 17.0% (624/3674; 16.1% to 17.9%) of the 1983 cohort in 1990. The proportion of doctors working in general practice was lower than in previous cohorts. The percentage of women in general practice (44.3% (528/1192)) substantially exceeded that of men (33.1% (443/1340)). 53% (276/522) of the women in general practice and 20% (98/490) of the women in hospital specialties worked part time.ConclusionsConcerns about recruitment difficulties in general practice are justified. Women are now entering general practice in greater numbers than men. There is no evidence of a greater exodus from the NHS from the 1988 qualifiers than from earlier cohorts.

Key messages

  • This study reports the career progress to September 1995 of doctors who qualified in 1988
  • Loss from the British NHS, at 16.9% (95% confidence interval, 16.1% to 17.8%), was no greater than among earlier qualifiers at the same time after qualification
  • The proportion of doctors working in general practice (38%) was lower than in earlier cohorts studied
  • In this generation of doctors, women in general practice now outnumber men
  • Fifty three per cent of the women in general practice and 20% of the women in hospital specialties were working on a part time or flexible basis
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18.
ObjectiveTo evaluate the effect of iron supplementation on the incidence of infections in children.DesignSystematic review of randomised controlled trials.InterventionsOral or parenteral iron supplementation or fortified formula milk or cereals.OutcomesIncidence of all recorded infectious illnesses, and individual illnesses, including respiratory tract infection, diarrhoea, malaria, other infections, and prevalence of positive smear results for malaria.ResultsThe pooled estimate (random effects model) of the incidence rate ratio (iron v placebo) was 1.02 (95% confidence interval 0.96 to 1.08, P=0.54; P<0.0001 for heterogeneity). The incidence rate difference (iron minus placebo) for all recorded illnesses was 0.06 episodes/child year (−0.06 to 0.18, P=0.34; P<0.0001 for heterogeneity). However, there was an increase in the risk of developing diarrhoea (incidence rate ratio 1.11, 1.01 to 1.23, P=0.04), but this would not have an overall important on public health (incidence rate difference 0.05 episodes/child year, –0.03 to 0.13; P=0.21). The occurrence of other illnesses and positive results on malaria smears (adjusted for positive smears at baseline) were not significantly affected by iron administration. On meta-regression, the statistical heterogeneity could not be explained by the variables studied.ConclusionIron supplementation has no apparent harmful effect on the overall incidence of infectious illnesses in children, though it slightly increases the risk of developing diarrhoea.

What is already known on this topic

Iron supplementation is recommended to prevent iron deficiency, which is a major health problem, especially in the developing countriesConflicting data exist regarding the possibility of an increase in the incidence of infections with iron supplementation, resulting in concern about the safety of this intervention

What this study adds

Iron supplementation has no apparent harmful effect on the overall incidence of infectious illnesses in childrenIron administration increases the risk of developing diarrhoeaFortification of foods may be the safest and most beneficial mode of supplementation in relation to infectious illnesses  相似文献   

19.
ObjectiveTo determine whether attempts to prevent weight gain will increase success rates for stopping smoking.Design16 week, open, randomised study with 1 year follow up.SettingObesity unit.Subjects287 female smokers who had quit smoking before but started again because of weight concerns.InterventionCombination of a standard smoking cessation programme with nicotine gum and a behavioural weight control programme including a very low energy diet. A control group was treated with the identical programme but without the diet.ResultsAfter 16 weeks, 68/137 (50%) women had stopped smoking in the diet group versus 53/150 (35%) in the control group (P=0.01). Among these women, weight fell by mean 2.1 (95% confidence interval 2.9 to 1.3) kg in the diet group but increased by 1.6 (0.9 to 2.3) kg in the control group (P<0.001). After 1 year the success rates in the diet and control groups were 38/137 (28%) and 24/150 (16%) respectively (P<0.05), but there was no statistical difference in weight gain.ConclusionsCombining the smoking cessation programme with an intervention to control weight helped women to stop smoking and control weight.  相似文献   

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