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PubMed2004

Human albumin solution for resuscitation and volume expansion in critically ill patients.

BACKGROUND: Human albumin solutions are used in a range of medical and surgical problems. Licensed indications are the emergency treatment of shock and other conditions where restoration of blood volume is urgent, burns, and hypoproteinaemia. Human albumin solutions are more expensive than other colloids and crystalloids. OBJECTIVES: To quantify the effect on mortality of human albumin and plasma protein fraction (PPF) administration in the management of critically ill patients. SEARCH STRATEGY: We searched the Cochrane Injuries Group trials register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and BIDS Index to Scientific and Technical Proceedings. Reference lists of trials and review articles were checked, and authors of identified trials were contacted. The search was last updated in August 2004. SELECTION CRITERIA: Randomised controlled trials comparing albumin/PPF with no albumin/PPF, or with a crystalloid solution, in critically ill patients with hypovolaemia, burns or hypoalbuminaemia. DATA COLLECTION AND ANALYSIS: We collected data on the participants, albumin solution used, mortality at the end of follow up, and quality of allocation concealment. Analysis was stratified according to patient type. MAIN RESULTS: We found 32 trials meeting the inclusion criteria and reporting death as an outcome. There were 1632 deaths among 8452 trial participants. For hypovolaemia, the relative risk of death following albumin administration was 1.01 (95% confidence interval 0.92, 1.10). This estimate was heavily influenced by the results of the SAFE trial which contributed 91% of the information (based on the weights in the meta-analysis). For burns, the relative risk was 2.40 (1.11, 5.19) and for hypoalbuminaemia the relative risk was 1.38 (0.94, 2.03). There was no substantial heterogeneity between the trials in the various categories (chi-square = 21.86, df = 25, p =0.64). The pooled relative risk of death with albumin administration was 1.04 (0.95, 1.13). REVIEWERS' CONCLUSIONS: For patients with hypovolaemia there is no evidence that albumin reduces mortality when compared with cheaper alternatives such as saline. There is no evidence that albumin reduces mortality in critically ill patients with burns and hypoalbuminaemia. The possibility that there may be highly selected populations of critically ill patients in which albumin may be indicated remains open to question. However, in view of the absence of evidence of a mortality benefit from albumin and the increased cost of albumin compared to alternatives such as saline, it would seem reasonable that albumin should only be used within the context of well concealed and adequately powered randomised controlled trial.

Blood Proteins↗
PubMed2001

Transcutaneous electrical nerve stimulation (TENS) for chronic pain.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is used in a variety of different clinical settings to treat a range of different acute and chronic pain conditions and has become popular with both patients and health professionals. OBJECTIVES: To evaluate the effectiveness of TENS in chronic pain. SEARCH STRATEGY: The Cochrane Library, Embase, Medline, CINAHL and The Oxford Pain Database were searched. Reference lists from retrieved reports and reviews were examined. Date of the most recent search: March 1999. SELECTION CRITERIA: RCTs were eligible if they included the following treatment comparisons: active TENS versus sham TENS controls active TENS versus no treatment controls active TENS versus active TENS controls (for instance High Frequency TENS vs Low Frequency TENS) Studies of patients suffering chronic pain for three months or more which included subjective outcome measures for pain intensity, or pain relief were eligible for evaluation in this review. No restrictions were made to language or sample size. Data from abstracts, letters, or unpublished studies, and studies of TENS in angina, headache and migraine, and dysmenorrhoea were not included. DATA COLLECTION AND ANALYSIS: Data were extracted and summarised on the following items: patients and details of pain condition, study treatments, study duration, design, methods, subjective pain outcome measures, methodological quality, results for pain outcome measures and adverse effects, and the conclusions made by the authors of the original studies. Extracted data and methodological quality of each report was confirmed by at least three of the reviewers. MAIN RESULTS: Of 107 reports identified from the searches, 88 were excluded as they did not fulfil the pre-defined entry criteria. Nineteen RCTs (from 18 reports) were evaluated. The included trials varied in terms of design, analgesic outcomes, chronic pain conditions, TENS treatments and overall methodological quality. Studies included single and multiple dose treatment comparisons of TENS. The studies were small. The reporting of the methods used and results for the analgesic outcomes were generally poor. TENS treatments and controls were often poorly defined. Few studies evaluated the long-term analgesic effectiveness of TENS and single dose evaluations of TENS are unhelpful in making clinical decisions of the long-term effectiveness of TENS in the management of chronic pain. Meta-analysis was not possible. Overall in 10 of 15 inactive control studies there was a positive analgesic outcome in favour of the active TENS treatments. For the multiple dose treatment comparison studies only three of seven were considered to be in favour of the active TENS treatments. For the active controlled studies, seven studies made direct comparisons between HFTENS and LFTENS. Five of seven studies could find no difference in terms of analgesic efficacy between HFTENS and LFTENS at any time point. REVIEWER'S CONCLUSIONS: The results of this review are inconclusive; the published trials do not provide information on the stimulation parameters which are most likely to provide optimum pain relief, nor do they answer questions about long-term effectiveness. Large multi-centre randomised controlled trials of TENS in chronic pain are urgently needed.

Chronic Disease↗
PubMed2005

Laryngeal mask airway versus bag-mask ventilation or endotracheal intubation for neonatal resuscitation.

BACKGROUND: Providing effective positive pressure ventilation is the single most important component of successful neonatal resuscitation. Ventilation is frequently initiated with a manual resuscitation bag and face-mask (BMV) followed by endotracheal intubation (ETT) if depression continues. These techniques may be difficult to perform successfully resulting in prolonged resuscitation or severe neonatal depression. The laryngeal mask airway (LMA) may achieve initial ventilation and successful resuscitation faster than a bag-mask device or endotracheal intubation. OBJECTIVES: Among newborns requiring positive pressure ventilation for resuscitation, is effective ventilation and successful resuscitation achieved faster with the LMA compared with either BMV or ETT? SEARCH STRATEGY: The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2004), MEDLINE (1966-November 2004), Pre-MEDLINE (November 15, 2004), CINAHL 1982-November 2004), reference lists of published trials, and Society for Pediatric Research abstracts were searched. Experts were contacted for additional references. SELECTION CRITERIA: Randomised and quasi-randomised trials DATA COLLECTION AND ANALYSIS: Two reviewers independently evaluated studies, assessed methodologic quality, and extracted data using the Cochrane Neonatal Review Group criteria. Categorical treatment effects were described as relative risks and risk differences and continuous treatment effects were described as the mean difference. There were insufficient data to perform pooled analyses. MAIN RESULTS: No eligible studies compared the LMA with BMV. One small randomised controlled trial comparing the LMA with ETT when BMV had been unsuccessful was included. There was no statistically significant difference between the LMA and ETT with the exception of a clinically insignificant difference in time to complete insertion of the device favouring the ETT. AUTHORS' CONCLUSIONS: The LMA can achieve effective ventilation during neonatal resuscitation in a time-frame consistent with current guidelines. There is no evidence to evaluate the relative efficacy and safety of the LMA compared with BMV as the primary airway device. A single, small randomised controlled trial found no clinically significant difference between the LMA and ETT when BMV was unsuccessful. Case series and case reports suggest that the LMA can provide an effective rescue airway during resuscitation if both BMV and ETT have been unsuccessful. A well-designed randomised controlled trial comparing the LMA with BMV during neonatal resuscitation is warranted.

Humans↗
PubMed2002

Heliox for treatment of exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Due to its low density properties, helium-oxygen mixtures have the potential to decrease the work of breathing and possibly avoid the need for intubation and mechanical ventilation in patients with respiratory failure. OBJECTIVES: To determine the effect of the addition of helium/oxygen mixtures (heliox) to standard medical care during ventilated and nonventilated acute exacerbations of COPD. SEARCH STRATEGY: Randomized controlled trials were identified from the Cochrane Airways Review Group asthma Register. Primary authors and experts were contacted. References from included and excluded studies, known reviews and texts were also searched. SELECTION CRITERIA: Studies were selected for inclusion if they compared treatment with heliox to placebo (oxygen or air) in randomized controlled trials in adults with an exacerbation of COPD. DATA COLLECTION AND ANALYSIS: Data from all trials were combined using the Review Manager (version 4.1). We planned to perform: 1) random effects weighted mean difference (WMD), with 95% confidence intervals (95% CI), 2) Homogeneity of effect sizes with the Dersimonian and Laird method with p<0.1 as the cut point for significance, and 3) sensitivity analysis on different helium-oxygen mixtures (80/20 vs 70/30), and 4) methodological quality (Jadad score >2 vs. <3). MAIN RESULTS: Four studies, all published between 1997 and 2000 met the inclusion criteria. Two studies compared heliox-oxygen vs. air-oxygen in decompensated COPD patients who were not ventilated. One study was performed in mechanical ventilated patients and one in patients undergoing noninvasive pressure support (NIPSV) ventilated patients. Data could be obtained for only two of the studies. One was a randomized crossover study of 70:30 helium-oxygen vs air-oxygen that involved nineteen patients with acute severe COPD, hospitalized in an intensive care unit for NIPSV. In the patients receiving heliox, arterial PCO2 fell more; WMD 0.8 kPa (95% CI 0.26, -1.34). The second was a randomized trial involved 47 patients with acute COPD, who presented to an Emergency Department randomized to receive updraft nebulization of albuterol and ipratropium bromide using 80% helium and 20% oxygen or compressed air as the driving gas. Treatments were administered at 0, 20, 40, and 120 minutes after randomization. There were no significant differences in the change of FEV1 and FVC between the two groups by either the 1 or 2 hours point. although a small improvement in FEF 25-75 was significantly greater in the heliox group than in the air group. REVIEWER'S CONCLUSIONS: There is currently insufficient evidence to support the use of helium-oxygen mixtures to treat acute exacerbations of COPD in either ventilated or nonventilated patients. Suitably designed randomised controlled trials with the endpoint being the avoidance of mechanical ventilation may be justified.

Helium↗
PubMed2002

Systematic reviews of treatment for inflammatory demyelinating neuropathy.

This review describes the progress made in preparing Cochrane systematic reviews of randomized controlled trials for Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy (MMN) and the demyelinating neuropathies associated with paraproteins. The discovery of antibodies against myelin and axolemmal glycolipids and proteins has not yet replaced the clinicopathological classification on which treatment trials have been based. Systematic reviews have endorsed the equivalence of plasma exchange (PE) and intravenous immunoglobulin (IVIg) and the lack of efficacy of steroids in GBS. Systematic reviews have also endorsed the value of steroids, PE and IVIg in CIDP but randomized controlled trials have only shown benefit from IVIg in MMN. There is a paucity of evidence concerning the efficacy of treatments in paraproteinaemic demyelinating neuropathy apartment from small trials showing short-term benefit from PE or IVIg. There is a lack of good quality controlled trials of immunosuppressive agents in any of these conditions. As the number of treatment trials increases, Cochrane systematic reviews will be an increasingly valuable resource for summarizing the evidence from randomised controlled trials on which to base clinical practice. They already demonstrate major deficiencies in the existing evidence base.

Glucocorticoids↗
PubMed2003

Descriptive survey of non-commercial randomised controlled trials in the United Kingdom, 1980-2002.

OBJECTIVES: To describe the characteristics of randomised controlled trials supported by the main non-commercial sources of funding in the United Kingdom between 1980 and 2002. DESIGN: Descriptive survey. SETTING: Randomised controlled trials funded by the Medical Research Council, NHS research and development programme, Department of Health, Chief Scientist Office in Scotland, and medical research charities. PARTICIPANTS: 1464 randomised controlled trials supported by the main non-commercial sources of funding. RESULTS: Support for randomised controlled trials by the main sources of non-commercial funding in the United Kingdom has fallen in recent years, without any concomitant increase in the sample sizes of these studies. Drug trials in a limited range of health problems have dominated among the studies supported by the Medical Research Council and medical research charities. Until recently, the NHS research and development programme supported randomised controlled trials of various healthcare interventions, in a wide range of health problems, but between 1999 and 2002 many of the subprogrammes that had commissioned trials were discontinued. CONCLUSIONS: The future of non-commercial randomised controlled trials in the United Kingdom has been threatened by the discontinuation or demise of national and regional NHS research and development programmes. Support also seems to be declining from the Medical Research Council and the medical research charities. It is unclear what the future holds for randomised controlled trials that address issues of no interest to industry but are of great importance to patients and practitioners.

Financing, Organized↗
PubMed2003

Evaluation of an evidence based patient educational booklet for management of whiplash associated disorders.

OBJECTIVES: This study aimed to develop and evaluate an evidence based educational booklet on whiplash associated disorders. METHODS: A comprehensive review of the available scientific evidence produced a set of unambiguous patient centred messages that challenge unhelpful beliefs about whiplash and promote an active approach to recovery. These messages were incorporated into a novel booklet, which was then evaluated qualitatively for end user acceptability and its ability to impart the intended messages, and quantitatively for its ability to improve beliefs about whiplash and what to do about it. The subjects comprised people attending accident and emergency or manipulative practice with a whiplash associated disorder, along with a sample of workers without a whiplash associated disorder (n = 142). RESULTS: The qualitative results showed that the booklet was considered easy to read, understandable, believable, and conveyed its key messages. Quantitatively, it produced a substantial statistically significant improvement in beliefs about whiplash among accident and emergency patients (mean 6.5, 95% CI 3.9 to 9.1, p<0.001), and among workers (mean 9.4, 95% CI 7.9 to 10.9, p<0.001), but the shift in the more chronic manipulation patients was substantially smaller (mean 3.3, 95% CI 0.5 to 6.1, p<0.05). CONCLUSIONS: A rigorously developed educational booklet on whiplash (The Whiplash Book) was found acceptable to patients, and capable of improving beliefs about whiplash and its management; it seems suitable for use in the accident and emergency environment, and for wider distribution at the population level. A randomised controlled trial would be required to determine whether it exerts an effect on behaviour and clinical outcomes.

Adolescent↗
PubMed2004

A survey of statistics in three UK general practice journal.

BACKGROUND: Many medical specialities have reviewed the statistical content of their journals. To our knowledge this has not been done in general practice. Given the main role of a general practitioner as a diagnostician we thought it would be of interest to see whether the statistical methods reported reflect the diagnostic process. METHODS: Hand search of three UK journals of general practice namely the British Medical Journal (general practice section), British Journal of General Practice and Family Practice over a one-year period (1 January to 31 December 2000). RESULTS: A wide variety of statistical techniques were used. The most common methods included t-tests and Chi-squared tests. There were few articles reporting likelihood ratios and other useful diagnostic methods. There was evidence that the journals with the more thorough statistical review process reported a more complex and wider variety of statistical techniques. CONCLUSIONS: The BMJ had a wider range and greater diversity of statistical methods than the other two journals. However, in all three journals there was a dearth of papers reflecting the diagnostic process. Across all three journals there were relatively few papers describing randomised controlled trials thus recognising the difficulty of implementing this design in general practice.

Bibliometrics↗
PubMed2003

Homeopathic treatment for premenstrual symptoms.

Premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) are well-documented disorders causing significant morbidity in the female population. Treatments prescribed do not necessarily reflect proven clinical effectiveness. A recent systematic review from the Exeter Department of Complementary Medicine failed to endorse complementary therapies as a whole for treatment of PMS. However, a recent randomised controlled trial of homeopathic treatment for PMS confirms the clinical experience of homeopathic physicians that homeopathy is helpful in PMS.

Adult↗
PubMed1999

Grading of scientific evidence--a discussion paper from SHPIC.

This paper examines some of the issues in the grading and use of evidence, and suggests that the (US) Agency for Health Care Policy and Research (AHCPR) system used by the Scottish Intercollegiate Guidelines Network (SIGN) and others is useful, but that it needs development to take account not only of type of study, but also of quality. It also considers the need to complement evidence of efficacy from randomised controlled trials, which may involve selected patients in selected centres, with evidence of "real-life" effectiveness. Furthermore, there are occasions where randomised controlled trials are not necessary. A grading system to take account of these issues is proposed for discussion.

Decision Making, Organizational↗
PubMed2004

Oral contraceptives, menopause hormone replacement therapy, and risk of stroke.

OBJECTIVES: To review available evidence from observational and intervention studies on oral contraceptives (OC), menopause hormone replacement therapy (HRT) and stroke. METHODS: Qualitative literature review. RESULTS: High dose OC were associated to elevated risk of stroke. However, the use of low oestrogen OC preparations by non-hypertensive women not at high baseline risk is not related to an appreciable risk of stroke. With reference to HRT, randomised clinical trials showed an excess risk of stroke among users of combined therapy. CONCLUSIONS: In non-hypertensive women below age 35 stroke is not materially related to the use of low dose OC. HRT is associated to a moderate excess risk in randomised studies, and should therefore not be used for the prevention of stroke.

Contraceptives, Oral, Combined↗
PubMed2004

A definition of causal effect for epidemiological research.

Estimating the causal effect of some exposure on some outcome is the goal of many epidemiological studies. This article reviews a formal definition of causal effect for such studies. For simplicity, the main description is restricted to dichotomous variables and assumes that no random error attributable to sampling variability exists. The appendix provides a discussion of sampling variability and a generalisation of this causal theory. The difference between association and causation is described-the redundant expression "causal effect" is used throughout the article to avoid confusion with a common use of "effect" meaning simply statistical association-and shows why, in theory, randomisation allows the estimation of causal effects without further assumptions. The article concludes with a discussion on the limitations of randomised studies. These limitations are the reason why methods for causal inference from observational data are needed.

Causality↗