Publication bias of randomized controlled trials in emergency medicine

An umbrella review of effect size, bias, and power across meta-analyses in emergency medicine

OBJECTIVES

The objective of this study was to conduct an umbrella review of therapeutic studies relevant to emergency medicine, analyzing patterns in effect size, power, and signals of potential bias across an entire field of clinical research.

METHODS

We combined topic- and journal-driven searches of PubMed and Google Scholar for published articles of systematic reviews and meta-analyses (SRMA) relevant to emergency medicine (last search in November 2020). Data were screened and extracted by six investigators. Redundant meta-analyses were removed. Whenever possible for each comparison we extracted one meta-analysis on mortality with the most events and one meta-analysis on a nonmortality outcome with the most studies. From each meta-analysis we extracted all individual study effects; outcomes were converted to odds ratios (ORs) and placed on a common scale where an OR < 1.0 represents a reduction in a harmful outcome with an experimental treatment versus control. Outcomes were analyzed at the level of individual studies and at the level of summary effects across meta-analyses.

RESULTS

A total of 332 articles contained 431 eligible meta-analyses with a total of 3,129 individual study outcomes; of these, 2,593 (83%) were from randomized controlled trials. The median OR across all studies was 0.70. Within each meta-analysis, the earliest study effect on average demonstrated larger benefit compared to the overall summary effect. Only 57 of 431 meta-analyses (13%) both favored the experimental intervention and did not show any signal of small study effects or excess significance, and of those only 12 had at least one study with 80% or higher power to detect an OR of 0.70. Of these, no interventions significantly decreased mortality in well-powered trials. Although the power of studies increased somewhat over time, the majority of studies were underpowered.

CONCLUSIONS

Few interventions studied within SRMAs relevant to emergency medicine seem to have strong and unbiased evidence for improving outcomes. The field would benefit from more optimally powered trials.

Preclinical Evidence and Possible Mechanisms of Rhodiola rosea L. and Its Components for Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: Rhodiola rosea L. has long been used as traditional medicines in Europe and Asia to treat a variety of common conditions and diseases including Alzheimer's disease, cardiovascular disease, cognitive dysfunctions, cancer, and stroke. Previous studies reported that Rhodiola rosea L. and its components (RRC) improve ischemia stroke in animal models. Here, we conducted a systematic review and meta-analysis for preclinical studies to evaluate the effects of RRC and the probable neuroprotective mechanisms in ischemic stroke. Methods: Studies of RRC on ischemic stroke animal models were searched in seven databases from inception to Oct 2021. The primary measured outcomes included the neural functional deficit score (NFS), infarct volume (IV), brain water content, cell viability, apoptotic cells, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells, B-cell lymphoma-2 (Bcl-2) level and tumor necrosis factor-α (TNF-α) level. The secondary outcome measures were possible mechanisms of RRC for ischemic stroke. All the data were analyzed via RevMan version 5.3. Results: 15 studies involving 345 animals were identified. Methodological quality for each included studies was accessed according to the CAMARADES 10-item checklist. The quality score of studies range from 1 to 7, and the median was 5.53. Pooled preclinical data showed that compared with the controls, RRC could improve NFS (Zea Longa (p < 0.01), modified neurological severity score (mNSS) (p < 0.01), rotarod tests (p < 0.01), IV (p < 0.01), as well as brain edema (p < 0.01). It also can increase cell viability (p < 0.01), Bcl-2 level (p < 0.01) and reduce TNF-α level (p < 0.01), TUNEL-positive cells (p < 0.01), apoptotic cells (p < 0.01). Conclusion: The findings suggested that RRC can improve ischemia stroke. The possible mechanisms of RRC are largely through antioxidant, anti-apoptosis activities, anti-inflammatory, repressing lipid peroxidation, antigliosis, and alleviating the pathological blood brain barrier damage.

Throughput interventions to reduce emergency department crowding: A systematic review

Objective

Emergency department (ED) throughput efficiency is largely dependent on staffing and process, and many operational interventions to increase throughput have been described.

Methods

We systematically searched Medline, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials to find studies describing the impact of throughput strategies on ED length of stay and left without being seen rates. Two independent reviewers screened studies, evaluated quality and risk of bias, and stratified eligible studies by intervention type. We assessed statistical heterogeneity using the chi-squared statistic and the I-squared (I2) statistic, and pooled results where appropriate. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

Results

Ninety-four (94) studies met inclusion criteria (Cohen's k = 0.7). Most were observational, five were determined to be low quality (Cohen's k = 0.6), and almost all reported modest reductions in length of stay and left without being seen rates, although there was substantial variability within and between intervention types. Fast track and patient streaming interventions showed the most consistent reduction in length of stay and left without being seenrates. Shifting high-level providers to triage appears effective and generally cost neutral. Evidence for enhanced testing strategies and alternative staffing models was less compelling.

Conclusions

Introducing a fast track and optimizing processes for important case-mix groups will likely enhance throughput efficiency. Expediting diagnostic and treatment decisions by shifting physician-patient contact to the earliest possible process point (e.g., triage) is an effective cost-neutral strategy to increase flow. Focusing ED staff on operational improvement is likely to improve performance, regardless of the intervention type.

Extracts or Active Components from Acorus gramineus Aiton for Cognitive Function Impairment: Preclinical Evidence and Possible Mechanisms

Extracts or active components from Acorus gramineus Aiton (EAAGA) have been clinically used for cognition impairment more than hundreds of years and are still used in modern times in China and elsewhere worldwide. Previous studies reported that EAAGA improves cognition impairment in animal models. Here, we conducted a preclinical systematic review to assess the current evidence of EAAGA for cognition impairment. We searched 7 databases up until June 2019. Methodological quality for each included studies was accessed according to the CAMARADES 10-item checklist. The primary outcome measures were neurobehavioral function scores evaluated by the Morris water maze test, electrical Y-maze test, step-down test, radial eight-arm maze test, and step-through test. The secondary outcome measures were mechanisms of EAAGA for cognition function. Finally, 34 studies involving 1431 animals were identified. The quality score of studies range from 1 to 6, and the median was 3.32. Compared with controls, the results of the meta-analysis indicated EAAGA exerted a significant effect in decreasing the escape latency and error times and in increasing the length of time spent in the platform quadrant and the number of platform crossings representing learning ability and memory function (all P < 0.01). The possible mechanisms of EAAGA are largely through anti-inflammatory, antioxidant, antiapoptosis activities, inhibition of neurotoxicity, regulating synaptic plasticity, protecting cerebrovascular, stimulating cholinergic system, and suppressing astrocyte activation. In conclusion, EAAGA exert potential neuroprotective effects in experimental cognition impairment, and EAAGA could be a candidate for cognition impairment treatment and further clinical trials.

Full publication of results initially presented in abstracts

BACKGROUND

Abstracts of presentations at scientific meetings are usually available only in conference proceedings. If subsequent full publication of results reported in these abstracts is based on the magnitude or direction of the results, publication bias may result. Publication bias creates problems for those conducting systematic reviews or relying on the published literature for evidence about health and social care.

OBJECTIVES

To systematically review reports of studies that have examined the proportion of meeting abstracts and other summaries that are subsequently published in full, the time between meeting presentation and full publication, and factors associated with full publication.

SEARCH METHODS

We searched MEDLINE, Embase, the Cochrane Library, Science Citation Index, reference lists, and author files. The most recent search was done in February 2016 for this substantial update to our earlier Cochrane Methodology Review (published in 2007).

SELECTION CRITERIA

We included reports of methodology research that examined the proportion of biomedical results initially presented as abstracts or in summary form that were subsequently published. Searches for full publications had to be at least two years after meeting presentation.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed risk of bias. We calculated the proportion of abstracts published in full using a random-effects model. Dichotomous variables were analyzed using risk ratio (RR), with multivariable models taking into account various characteristics of the reports. We assessed time to publication using Kaplan-Meier survival analyses.

MAIN RESULTS

Combining data from 425 reports (307,028 abstracts) resulted in an overall full publication proportion of 37.3% (95% confidence interval (CI), 35.3% to 39.3%) with varying lengths of follow-up. This is significantly lower than that found in our 2007 review (44.5%. 95% CI, 43.9% to 45.1%). Using a survival analyses to estimate the proportion of abstracts that would be published in full by 10 years produced proportions of 46.4% for all studies; 68.7% for randomized and controlled trials and 44.9% for other studies. Three hundred and fifty-three reports were at high risk of bias on one or more items, but only 32 reports were considered at high risk of bias overall.Forty-five reports (15,783 abstracts) with 'positive' results (defined as any 'significant' result) showed an association with full publication (RR = 1.31; 95% CI 1.23 to 1.40), as did 'positive' results defined as a result favoring the experimental treatment (RR =1.17; 95% CI 1.07 to 1.28) in 34 reports (8794 abstracts). Results emanating from randomized or controlled trials showed the same pattern for both definitions (RR = 1.21; 95% CI 1.10 to 1.32 (15 reports and 2616 abstracts) and RR = 1.17; 95% CI, 1.04 to 1.32 (13 reports and 2307 abstracts), respectively.Other factors associated with full publication include oral presentation (RR = 1.46; 95% CI 1.40 to 1.52; studied in 143 reports with 115,910 abstracts); acceptance for meeting presentation (RR = 1.65; 95% CI 1.48 to 1.85; 22 reports with 22,319 abstracts); randomized trial design (RR = 1.51; 95% CI 1.36 to 1.67; 47 reports with 28,928 abstracts); and basic research (RR = 0.78; 95% CI 0.74 to 0.82; 92 reports with 97,372 abstracts). Abstracts originating at an academic setting were associated with full publication (RR = 1.60; 95% CI 1.34 to 1.92; 34 reports with 16,913 abstracts), as were those considered to be of higher quality (RR = 1.46; 95% CI 1.23 to 1.73; 12 reports with 3364 abstracts), or having high impact (RR = 1.60; 95% CI 1.41 to 1.82; 11 reports with 6982 abstracts). Sensitivity analyses excluding reports that were abstracts themselves or classified as having a high risk of bias did not change these findings in any important way.In considering the reports of the methodology research that we included in this review, we found that reports published in English or from a native English-speaking country found significantly higher proportions of studies published in full, but that there was no association with year of report publication. The findings correspond to a proportion of abstracts published in full of 31.9% for all reports, 40.5% for reports in English, 42.9% for reports from native English-speaking countries, and 52.2% for both these covariates combined.

AUTHORS' CONCLUSIONS

More than half of results from abstracts, and almost a third of randomized trial results initially presented as abstracts fail to be published in full and this problem does not appear to be decreasing over time. Publication bias is present in that 'positive' results were more frequently published than 'not positive' results. Reports of methodology research written in English showed that a higher proportion of abstracts had been published in full, as did those from native English-speaking countries, suggesting that studies from non-native English-speaking countries may be underrepresented in the scientific literature. After the considerable work involved in adding in the more than 300 additional studies found by the February 2016 searches, we chose not to update the search again because additional searches are unlikely to change these overall conclusions in any important way.

Primary care professionals providing non-urgent care in hospital emergency departments

BACKGROUND

In many countries emergency departments (EDs) are facing an increase in demand for services, long waits, and severe crowding. One response to mitigate overcrowding has been to provide primary care services alongside or within hospital EDs for patients with non-urgent problems. However, it is unknown how this impacts the quality of patient care and the utilisation of hospital resources, or if it is cost-effective. This is the first update of the original Cochrane Review published in 2012.

OBJECTIVES

To assess the effects of locating primary care professionals in hospital EDs to provide care for patients with non-urgent health problems, compared with care provided by regularly scheduled emergency physicians (EPs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (the Cochrane Library; 2017, Issue 4), MEDLINE, Embase, CINAHL, PsycINFO, and King's Fund, from inception until 10 May 2017. We searched ClinicalTrials.gov and the WHO ICTRP for registered clinical trials, and screened reference lists of included papers and relevant systematic reviews.

SELECTION CRITERIA

Randomised trials, non-randomised trials, controlled before-after studies, and interrupted time series studies that evaluated the effectiveness of introducing primary care professionals to hospital EDs attending to patients with non-urgent conditions, as compared to the care provided by regularly scheduled EPs.  DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified four trials (one randomised trial and three non-randomised trials), one of which is newly identified in this update, involving a total of 11,463 patients, 16 general practitioners (GPs), 9 emergency nurse practitioners (NPs), and 69 EPs. These studies evaluated the effects of introducing GPs or emergency NPs to provide care to patients with non-urgent problems in the ED, as compared to EPs for outcomes such as resource use. The studies were conducted in Ireland, the UK, and Australia, and had an overall high or unclear risk of bias. The outcomes investigated were similar across studies, and there was considerable variation in the triage system used, the level of expertise and experience of the medical practitioners, and type of hospital (urban teaching, suburban community hospital). Main sources of funding were national or regional health authorities and a medical research funding body.There was high heterogeneity across studies, which precluded pooling data. It is uncertain whether the intervention reduces time from arrival to clinical assessment and treatment or total length of ED stay (1 study; 260 participants), admissions to hospital, diagnostic tests, treatments given, or consultations or referrals to hospital-based specialist (3 studies; 11,203 participants), as well as costs (2 studies; 9325 participants), as we assessed the evidence as being of very low-certainty for all outcomes.No data were reported on adverse events (such as ED returns and mortality).

AUTHORS' CONCLUSIONS

We assessed the evidence from the four included studies as of very low-certainty overall, as the results are inconsistent and safety has not been examined. The evidence is insufficient to draw conclusions for practice or policy regarding the effectiveness and safety of care provided to non-urgent patients by GPs and NPs versus EPs in the ED to mitigate problems of overcrowding, wait times, and patient flow.

Primary care professionals providing non-urgent care in hospital emergency departments

BACKGROUND

In many countries emergency departments (EDs) are facing an increase in demand for services, long-waits and severe crowding. One response to mitigate overcrowding has been to provide primary care services alongside or within hospital EDs for patients with non-urgent problems. It is not known, however, how this impacts the quality of patient care, the utilisation of hospital resources, or if it is cost-effective. 

OBJECTIVES

To assess the effects of locating primary care professionals in the hospital ED to provide care for patients with non-urgent health problems, compared with care provided by regular Emergency Physicians (EPs),

SEARCH METHODS

We searched the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialized register; Cochrane Central Register of Controlled Trials (The Cochrane library, 2011, Issue 4), MEDLINE (1950 to March 21 2012); EMBASE (1980 to April 28 2011); CINAHL (1980 to April 28 2011); PsychINFO (1967 to April 28 2011); Sociological Abstracts (1952 to April 28 2011); ASSIA (1987 to April 28 2011); SSSCI (1945 to April 28 2011); HMIC (1979 to April 28 2011), sources of unpublished literature, reference lists of included papers and relevant systematic reviews. We contacted experts in the field for any published or unpublished studies, and hand searched ED conference abstracts from the last three years.

SELECTION CRITERIA

Randomised controlled trials, non-randomised studies, controlled before and after studies and interrupted time series studies that evaluated the effectiveness of introducing primary care professionals to hospital EDs to attend to non-urgent patients, as compared to the care provided by regular EPs. 

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed the risk of bias for each included study. We contacted authors of included studies to obtain additional data. Dichotomous outcomes are presented as risk ratios (RR) with 95% confidence intervals (CIs) and continuous outcomes are presented as mean differences (MD) with 95% CIs. Pooling was not possible due to heterogeneity.

MAIN RESULTS

Three non randomised controlled studies involving a total of 11 203 patients, 16 General Practioners (GPs), and 52 EPs, were included. These studies evaluated the effects of introducing GPs to provide care to patients with non-urgent problems in the ED, as compared to EPs for outcomes such as resource use. The quality of evidence for all outcomes in this review was low, primarily due to the non-randomised design of included studies.The outcomes investigated were similar across studies; however there was high heterogeneity (I(2)>86%). Differences across studies included the triage system used, the level of expertise and experience of the medical practitioners and type of hospital (urban teaching, suburban community hospital).Two of the included studies report that GPs used significantly fewer healthcare resources than EPs, with fewer blood tests (RR 0.22; 95%CI: 0.14 to 0.33; N=4641; RR 0.35; 95%CI 0.29 to 0.42; N=4684), x-rays (RR 0.47; 95% CI 0.41 to 0.54; N=4641; RR 0.77 95% CI 0.72 to 0.83; N=4684), admissions to hospital (RR 0.33; 95% CI 0.19 to 0.58; N=4641; RR 0.45; 95% CI 0.36 to 0.56; N=4684) and referrals to specialists (RR 0.50; 95% CI 0.39 to 0.63; N=4641; RR 0.66; 95% CI 0.60 to 0.73; N=4684). One of the two studies reported no statistically significant difference in the number of prescriptions made by GPs compared with EPs, (RR 0.95 95% CI 0.88 to 1.03; N=4641), while the other showed that GPs prescribed significantly more medications than EPs (RR 1.45 95% CI 1.35 to 1.56; N=4684). The results from these two studies showed marginal cost savings from introducing GPs in hospital EDs.The third study (N=1878) failed to identify a significant difference in the number of blood tests ordered (RR 0.96; 95% CI 0.76 to 1.2), x-rays (RR 1.07; 95%CI 0.99 to 1.15), or admissions to hospital (RR 1.11; 95% CI 0.70 to 1.76), but reported a significantly greater number of referrals to specialists (RR 1.21; 95% CI 1.09 to 1.33) and prescriptions (RR 1.12; 95% CI 1.01 to 1.23) made by GPs as compared with EPs.No data were reported on patient wait-times, length of hospital stay, or patient outcomes, including adverse effects or mortality.

AUTHORS' CONCLUSIONS

Overall, the evidence from the three included studies is weak, as results are disparate and neither safety nor patient outcomes have been examined. There is insufficient evidence upon which to draw conclusions for practice or policy regarding the effectiveness and safety of care provided to non-urgent patients by GPs versus EPs in the ED to mitigate problems of overcrowding, wait-times and patient flow.

Effectiveness of corticosteroid treatment in acute pharyngitis: a systematic review of the literature

OBJECTIVES

The objective was to examine the effectiveness of corticosteroid treatment for the relief of pain associated with acute pharyngitis potentially caused by group A beta-hemolytic Streptococcus (GABHS).

METHODS

This was a systematic review of the literature. Data sources used were electronic databases (Cochrane Library, MEDLINE, EMBASE, Biosis Previews, Scopus, and Web of Science), controlled trial registration websites, conference proceedings, study references, experts in the field, and correspondence with authors. Selection criteria consisted of randomized controlled trials (RCTs) in which corticosteroids, alone or in combination with antibiotics, were compared to placebo or any other standard therapy for treatment of acute pharyngitis in adult patients, pediatric patients, or both. Two reviewers independently assessed for relevance, inclusion, and study quality. Weighted mean differences (WMDs) were calculated and are reported with corresponding 95% confidence intervals (CIs).

RESULTS

From 272 potentially relevant citations, 10 studies met the inclusion criteria. When compared to placebo, corticosteroids reduced the time to clinically meaningful pain relief (WMD = -4.54 hours; 95% CI = -7.19 to -1.89); however, they provided only a small reduction in pain scores at 24 hours (WMD = -0.90 on a 0-10 visual analog scale; 95% CI = -1.5 to -0.3). Heterogeneity among pooled studies was identified for both outcomes (I(2) = 81 and 74%, respectively); however, the GABHS-positive subgroup receiving corticosteroid treatment did have a significant mean reduction in time to clinically meaningful pain relief of 5.22 hours (95% CI = -7.02 to -3.42; I(2) = 0%). Short-term side effect profiles between corticosteroids and placebo groups were similar.

CONCLUSIONS

Corticosteroid administration for acute pharyngitis was associated with a relatively small effect in time to clinically meaningful pain relief (4.5-hour reduction) and in pain relief at 24 hours (0.9-point reduction), with significant heterogeneity in the pooled results. Decision-making should be individualized to determine the risks and benefits; however, corticosteroids should not be used as routine treatment for acute pharyngitis.

Does direction of results of abstracts submitted to scientific conferences on drug addiction predict full publication?

Background

Data from scientific literature show that about 63% of abstracts presented at biomedical conferences will be published in full. Some studies have indicated that full publication is associated with the direction of results (publication bias). No study has looked into the occurrence of publication bias in the field of addiction.

Objectives

To investigate whether the significance or direction of results of abstracts presented at the major international scientific conference on addiction is associated with full publication

Methods

The conference proceedings of the US Annual Meeting of the College on Problems of Drug Dependence (CPDD), were handsearched for abstracts of randomized controlled trials and controlled clinical trials that evaluated interventions for prevention, rehabilitation and treatment of drug addiction in humans (years searched 1993–2002). Data regarding the study designs and outcomes reported were extracted. Subsequent publication in peer reviewed journals was searched in MEDLINE and EMBASE databases, as of March 2006.

Results

Out of 5919 abstracts presented, 581 met the inclusion criteria; 359 (62%) conference abstracts had been published in a broad variety of peer reviewed journals (average time of publication 2.6 years, SD +/- 1.78). The proportion of published studies was almost the same for randomized controlled trials (62.4%) and controlled clinical trials (59.5%) while studies that reported positive results were significantly more likely to be published (74.5%) than those that did not report statistical results (60.9%.), negative or null results (47.1%) and no results (38.6%), Abstracts reporting positive results had a significantly higher probability of being published in full, while abstracts reporting null or negative results were half as likely to be published compared with positive ones (HR = 0.48; 95%CI 0.30–0.74)

Conclusion

Clinical trials were the minority of abstracts presented at the CPDD; we found evidence of possible publication bias in the field of addiction, with negative or null results having half the likelihood of being published than positive ones.

The relative efficacy of meperidine for the treatment of acute migraine: a meta-analysis of randomized controlled trials

STUDY OBJECTIVE

Despite guidelines recommending against opioids as first-line treatment for acute migraine, meperidine is the agent used most commonly in North American emergency departments. Clinical trials performed to date have been small and have not arrived at consistent conclusions about the efficacy of meperidine. We performed a systematic review and meta-analysis to determine the relative efficacy and adverse effect profile of opioids compared with nonopioid active comparators for the treatment of acute migraine.

METHODS

We searched multiple sources (Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, and LILACS, emergency and headache medicine conference proceedings) for randomized controlled trials comparing parenteral opioid and nonopioid active comparators for the treatment of acute migraine headache. Our primary outcome was relief of headache. If this was unavailable, we accepted rescue medication use or we transformed visual analog scale change scores by using an established procedure. We grouped studies by comparator: a regimen containing dihydroergotamine, antiemetic alone, or ketorolac. For each study, we calculated an odds ratio (OR) of headache relief and then assessed clinical and statistical heterogeneity for the group of studies. We then pooled the ORs of headache relief with a random-effects model.

RESULTS

From 899 citations, 19 clinical trials were identified, of which 11 were appropriate and had available data. Four trials involving 254 patients compared meperidine to dihydroergotamine, 4 trials involving 248 patients compared meperidine to an antiemetic, and 3 trials involving 123 patients compared meperidine to ketorolac. Meperidine was less effective than dihydroergotamine at providing headache relief (OR=0.30; 95% confidence interval [CI] 0.09 to 0.97) and trended toward less efficacy than the antiemetics (OR=0.46; 95% CI 0.19 to 1.11); however, the efficacy of meperidine was similar to that of ketorolac (OR=1.75; 95% CI 0.84 to 3.61). Compared to dihydroergotamine, meperidine caused more sedation (OR=3.52; 95% CI 0.87 to 14.19) and dizziness (OR=8.67; 95% CI 2.66 to 28.23). Compared to the antiemetics, meperidine caused less akathisia (OR=0.10; 95% CI 0.02 to 0.57). Meperidine and ketorolac use resulted in similar rates of gastrointestinal adverse effects (OR=1.27; 95% CI 0.31 to 5.15) and sedation (OR=1.70; 95% CI 0.23 to 12.72).

CONCLUSION

Clinicians should consider alternatives to meperidine when treating acute migraine with injectable agents.

Parenteral dexamethasone for acute severe migraine headache: meta-analysis of randomised controlled trials for preventing recurrence

OBJECTIVE

To examine the effectiveness of parenteral corticosteroids for the relief of acute severe migraine headache and prevention of recurrent headaches.

DESIGN

Meta-analysis.

DATA SOURCES

Electronic databases (Cochrane Central Register of Controlled Trials, Medline, Embase, LILACS, and CINAHL), conference proceedings, clinical practice guidelines, contacts with industry, and correspondence with authors.

SELECTION CRITERIA

Randomised controlled trials in which corticosteroids (alone or combined with standard abortive therapy) were compared with placebo or any other standard treatment for acute migraine in adults.

REVIEW METHODS

Two reviewers independently assessed relevance, inclusion, and study quality. Weighted mean differences and relative risks were calculated and are reported with 95% confidence intervals.

RESULTS

From 666 potentially relevant abstracts, seven studies met the inclusion criteria. All included trials used standard abortive therapy and subsequently compared single dose parenteral dexamethasone with placebo, examining pain relief and recurrence of headache within 72 hours. Dexamethasone and placebo provided similar acute pain reduction (weighted mean difference 0.37, 95% confidence interval -0.20 to 0.94). Dexamethasone was, however, more effective than placebo in reducing recurrence rates (relative risk 0.74, 95% confidence interval 0.60 to 0.90). Side effect profiles between dexamethasone and placebo groups were similar.

CONCLUSION

When added to standard abortive therapy for migraine headache, single dose parenteral dexamethasone is associated with a 26% relative reduction in headache recurrence (number needed to treat=9) within 72 hours.