Capnography versus standard monitoring for emergency department procedural sedation and analgesia

  • Protocol
  • Intervention

Authors


Abstract

This is the protocol for a review and there is no abstract. The objectives are as follows:

To assess whether capnography in addition to standard monitoring is more effective than only standard monitoring in ED patients undergoing procedural sedation and analgesia. Specifically, in ED patients undergoing procedural sedation and analgesia, the effect of using capnography in addition to standard monitoring on:

  • oxygen desaturation (SaO2 of < 90% for 30 second);

  • hypotension (systolic blood pressure of < 90 mm Hg);

  • emesis or pulmonary aspiration;

  • Need for airway intervention (airway repositioning manoeuvre, positive pressure ventilation, oral or nasal airway placement, endotracheal intubation);

  • recovery time (time from end of procedure to cessation of monitoring).

Background

Description of the condition

Procedural sedation and analgesia (PSA) is used very frequently in the modern emergency department (ED) under the auspices of emergency physicians and allied healthcare professionals. PSA is defined as the use of medications to induce an altered state of consciousness to safely facilitate painful procedures and interventions such as fracture reduction, cardioversion, and incision and drainage of abscesses without loss of spontaneous cardiopulmonary function (Godwin 2005). Despite widespread use, PSA is not without risk. Overshoot in the intended depth of sedation potentially resulting in respiratory compromise, loss of airway protection, and cardiovascular depression occurs in 1.3% to 10% of cases (Campbell 2006; Miner 2003; Swanson 1996). In a recent study (Deitch 2010), respiratory depression occurred in up to 39% of patients undergoing PSA with propofol. Emesis or pulmonary aspiration, or both, are of particular concern in patients with full stomachs who may be intoxicated and undergoing PSA in ED. Safeguards to reduce complications in ED PSA may include monitoring of heart rate, respiratory rate, blood pressure, and oxygen saturation.

Description of the intervention

Capnography, the continuous measurement of exhaled carbon dioxide (CO2) partial pressures, can be used in conjunction with other monitoring variables to determine the effects of sedation medications on ventilation and potentially prevent hypoxic events. This is accomplished by placement of an infrared sensor at the facemask or nasal cannula. The data output can be interpreted in the form of capnograms (CO2 waveforms versus time or expired volume) or end-tidal CO2 partial pressure (an estimation of alveolar CO2 partial pressure) (Kodali 2013). It is a widely accepted modality and used extensively for PSA in the operating room (OR) and the endoscopy suite in addition to standard PSA monitoring (Swanson 1996). While historically capnography use in the ED was limited to confirmation of endotracheal tube placement and for cardiac arrest, it is used with increasing frequency for PSA (Krauss 2007).

How the intervention might work

Sedation medications act to depress minute ventilation by decreasing respiration rate or tidal volume, or both. On a physiologic level, alterations in CO2 partial pressures (PCO2) are used to estimate changing pulmonary CO2 levels, a surrogate of changes in minute ventilation. Capnography can be used to detect decreasing trends of minute ventilation (that is ventilatory depression) earlier and steps can be taken (that is an airway intervention or medication or dose change) to correct the undesired physiologic disturbance (Barton 2006). Specifically, capnography data can be interpreted by monitoring for changes in end-tidal PCO2 (PETCO2), the shape of the capnogram, or arterial (a) and end-tidal PaCO2 - PETCO2 gradients (Kodali 2013). It is theorized that by using capnography in addition to other physiologic variables to detect ventilatory depression, cardio-respiratory complications such as hypoxia and hypotension can also be detected earlier and thus treated.

Why it is important to do this review

Recently, there has been a trend towards increased use of capnography in ED PSA despite limited evidence demonstrating its efficacy in this environment. The controlled environments of the OR and endoscopy suite are in contrast to the ED with respect to both patient population and procedures performed. ED visits are unplanned and patients often present in significant distress with full stomachs and they may have recently consumed alcohol or other recreational drugs. Considering this, conclusions derived from studies in OR and endoscopy settings do not necessarily apply to ED PSA. Only one published randomized controlled trial (RCT) has been performed studying capnography as a primary intervention in ED patients undergoing PSA (Deitch 2010). This study found that capnography both reduced and provided earlier detection of hypoxic events. The authors used definitions inconsistent with other literature, notably hypoxia (indirect measure of blood oxygen saturation (SpO2) < 93% for 15 seconds or greater), complicating the interpretation of their conclusions. A complete review of relevant studies is needed to improve generalizabilty and ultimately to provide a more powerful consensus on the utility of capnography in the ED.

Objectives

To assess whether capnography in addition to standard monitoring is more effective than only standard monitoring in ED patients undergoing procedural sedation and analgesia. Specifically, in ED patients undergoing procedural sedation and analgesia, the effect of using capnography in addition to standard monitoring on:

  • oxygen desaturation (SaO2 of < 90% for 30 second);

  • hypotension (systolic blood pressure of < 90 mm Hg);

  • emesis or pulmonary aspiration;

  • Need for airway intervention (airway repositioning manoeuvre, positive pressure ventilation, oral or nasal airway placement, endotracheal intubation);

  • recovery time (time from end of procedure to cessation of monitoring).

Methods

Criteria for considering studies for this review

Types of studies

We will only consider randomized and quasi-randomized controlled trials for inclusion. We will impose no language restrictions. We will include unpublished data if the trial meets the inclusion criteria.

Types of participants

We will include all ED patients requiring PSA. "Procedural sedation refers to the technique of administering sedatives or dissociative agents with or without analgesics to induce an altered state of consciousness that allows the patient to tolerate unpleasant procedures while preserving cardiorespiratory function" (Godwin 2005). We will include all age groups.  We will exclude patients receiving PSA in non-ED environments such as endoscopy suites or operating rooms (ORs) .    

Types of interventions

All patients must be randomized to either capnography in addition to standard monitoring (pulse oximetry, blood pressure, cardiac monitoring) or standard monitoring only.

Types of outcome measures

Primary outcomes
  1. Oxygen desaturation (SaO2 of < 90% for 30 seconds)

  2. Hypotension (systolic blood pressure of < 90 mmHg)

  3. Emesis, pulmonary aspiration

Secondary outcomes
  1. Airway interventions performed (airway repositioning manoeuvre, positive pressure ventilation, oral or nasal airway placement, endotracheal intubation)

  2. Recovery time (time from end of procedure to cessation of monitoring)

Outcomes will not form part of the study eligibility assessment so that studies that meet the participant, intervention, and comparison criteria will be included in the review even if they report no relevant outcomes.

Search methods for identification of studies

Electronic searches

We will search the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (latest issue); MEDLINE using PubMed (1980 to date); EMBASE (1980 to date); CINHAL (1982 to date).

We will impose no language or publication restrictions, or publication status restrictions. Please see Appendix 1 for the MEDLINE search. The MEDLINE search will be modified to reflect the subject headings employed by EMBASE, CINHAL, and CENTRAL.

We will review the reference lists of all available primary studies and review articles to identify potential relevant citations. 

Searching other resources

We will contact the authors of the primary studies to enquire whether they are aware of published or unpublished studies so that these results may be included in this review. We will contact scientific advisors of the various capnography device manufacturers. We will search for ongoing trials on the following websites: www.controlled-trials.com; www.clinicalstudyresults.org; and http://clinicaltrials.gov

We will handsearch Canadian Association of Emergency Physicians (CAEP); American College of Emergency Physicians (ACEP); Society for Academic Emergency Medicine (SAEM); and International Conference on Emergency Medicine (ICEM) conference abstract submissions for the past five years. Finally, we will make personal contact with colleagues, collaborators, and other trialists working in the field of ED PSA in order to identify potentially relevant studies.

Data collection and analysis

Selection of studies

We will combine the results from the search strategies into a reference manager program with duplicates excluded. All trials which appear relevant on the basis of title, abstract, and MeSH headings will be selected for full review by two authors (BW, KM).

From the potentially relevant articles identified, two authors (BW, KM) will independently select trials (based on the full text format) for inclusion in this review (see Appendix 2 for the article inclusion form). We will measure agreement using simple agreement and kappa statistics. We will resolve disagreements by discussion to reach consensus or third party adjudication (SC). Authors will not be blinded to information about the articles such as publication names, institutions involved, or conclusions made. A list of all included trials will be completed (see Appendix 3). Adjudication of the final list will be performed by a separate author (BW) and an independent third party for inclusion or exclusion from the selection of studies conducted by authors of this review.

Data extraction and management

Two authors (BW, KM) will independently extract data from the trials using an electronic data collection form (see Appendix 4). Disagreement not resolved by consensus will be adjudicated by a third author (SC). Any additional trial data required will be obtained by contacting the first trial author (BW). Data for trials conducted by authors of this review will be extracted by a separate author (BW) and an independent third party. Data extraction will include the following items.

  • General information: title, authors, contact address, publication source, publication year, country.

  • Methodological characteristics and study design.

  • Population characteristics: age, sedation agent used, procedure performed.

  • Intervention: capnography, definition of; capnography alert level.

  • Control: blood pressure, heart rate, oxygen saturation.

  • Outcome measures as noted above.

Assessment of risk of bias in included studies

We will perform the methodological quality assessment using the 'Risk of bias' tool detailed in Chapter 8 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We will use the quality assessment form attached as Appendix 5. Two authors (BW, KM) will independently perform this assessment with disagreement not resolved by consensus arbitrated by a third author (SC). We will not be blinded to the study authors or the results of the studies.

We will assess the following domains: random sequence generation; allocation concealment; blinding of participants and personnel; blinding of outcome assessment; incomplete outcome data; selective reporting. We will list all other biases that are identified in a final domain.

Measures of treatment effect

For dichotomous variables, we will calculate individual and pooled statistics as relative risks (RR) with 95% confidence intervals (95% CI). For continuous outcomes, we will calculate individual and pooled statistics as mean differences (MD) or standardized mean differences (SMD) and 95% CIs. 

Unit of analysis issues

We will not include cluster-randomized trials and cross-over trials. We do not anticipate any unit of analysis issues.

Dealing with missing data

We will complete an intention-to-treat (ITT) analysis, which deals with the 'missing data' issues from the individual trials.

Assessment of heterogeneity

We will assess clinical heterogeneity by analysing the methodological diversity (risk of bias assessment), clinical diversity (patient age, procedure performed, sedation agent used, definition of hypotension, definition of oxygen desaturation), and trial size (publication bias). We will perform subgroup and sensitivity analyses to address clinical heterogeneity, using forest plots to visually inspect CIs and both Chi2 tests and I2 statistics. We expect a small number of included studies, thus I2 values will be of particular importance with significant heterogeneity classified as a measured I2 statistic > 50% (Higgins 2011). In the absence of significant heterogeneity, we will conduct a meta-analysis using both a random-effects and a fixed-effect model.

Assessment of reporting biases

If publication bias is present, we will adjust the results using the Egger approach (Egger 1997) and the 'trim and fill' method. In the event that 10 or more studies are included in the review, we will create a funnel plot. In addition, we will use quality weighting to test the robustness of the results.

Data synthesis

In the absence of significant heterogeneity, we will conduct a meta-analysis using Review Manager Software (RevMan 5.2). To ensure the robustness of the results, we will use both a random-effects and a fixed-effect model. If heterogeneity exists and a meta-analysis is deemed inappropriate, we will perform a qualitative description of each included study's methodology and results. The criterion for statistical significance is a P value of less than 0.05 and 95% CIs that do not intersect.

Subgroup analysis and investigation of heterogeneity

As the utility of capnography in ED PSA may be dependent on the age of the patient, the sedation agent used, and the procedure performed, we plan to undertake the following subgroup analyses if significant heterogeneity (determined by the forest plot and I2 statistic) exists.

  1. Adults versus paediatrics (> 18 years old).

  2. Sedation agent used (propofol, ketamine, midazolam, lorazepam, fentanyl, etomidate, pentobarbital, methohexital).

  3. Procedure performed (fracture reduction, joint reduction, incision and drainage, suturing, cardioversion, lumbar puncture, diagnostic imaging, endoscopy, Foley catheter insertion, central line placement, dressing changes, burn debridement, ophthalmic procedure, dental procedure, temporomandibular joint (TMJ) reduction, chest tube insertion, other).

Sensitivity analysis

In order to test the robustness of our findings, we will perform a sensitivity analysis for trials with low risk versus high risk of bias. We will compare random-effects and fixed-effect model estimates for each outcome variable. In the event of any missing data, we will use the best case and worst case for imputation of missing data.

Summary of findings

We will use the principles of the GRADE system (Guyatt 2008) to assess the quality of the body of evidence associated with specific outcomes (oxygen desaturation, hypotension, emesis, pulmonary aspiration, airway interventions performed, recovery time) in our review and construct a summary of findings (SoF) table using the GRADE software. The GRADE approach appraises the quality of a body of evidence based on the extent to which one can be confident that an estimate of effect or association reflects the item being assessed. The quality of a body of evidence considers study risk of bias (methodologic quality), the directness of the evidence, heterogeneity of the data, precision of effect estimates, and risk of publication bias.

Acknowledgements

We would like to thank Mathew Zacharias (content editor), Cathal Walsh (statistical editor), Baruch Krauss and Teresa Williams (peer reviewers) for their help and editorial advice during the preparation of this protocol for the systematic review.

Appendices

Appendix 1. MEDLINE search strategy

(("Anesthesia, Intravenous"[Mesh] OR "Conscious Sedation"[Mesh] OR "Hypnotics and Sedatives"[Mesh]) OR (anesthes*[TIAB] OR ANAESTHES*[TIAB] OR SEDATE*[TIAB] OR SEDATION*[TIAB] OR SEDATIVE*[TIAB] OR HYPNOTIC*[TIAB])) AND (("Capnography"[Mesh] OR "Respiratory Insufficiency"[Mesh] OR "Monitoring, Physiologic"[Mesh] OR "Anoxia"[Mesh] OR "Carbon Dioxide"[Mesh]) OR (CAPNOGRAPH*[TIAB] OR "Respiratory Insufficiency"[TIAB] OR "respiratory failure"[tiab] OR ANOXIA*[TIAB] OR HYPOXI*[TIAB] OR "CARBON DIOXIDE"[TIAB])) AND (("Emergency Medical Services"[Mesh] OR "Emergency Service, Hospital"[Mesh]) OR (EMERGENC*[TIAB]) OR (casualt*[TIAB]))

Appendix 2. Article Inclusion Criteria Form

THE USE OF CAPNOGRAPHY IN EMERGENCY DEPARTMENT PROCEDURAL SEDATION AND ANALGESIA: A SYSTEMATIC REVIEW CRITERIA FOR INCLUSION

Citation # ____________
Reviewer:              BW                         KM

Please assess the following questions for each paper.  WHEN YOU OBTAIN ONE X (NOT INCLUDED) STOP.  The inclusion criteria are:

[1] DESIGN
  1. [ ] Randomized controlled clinical trial OR Quazi randomized controlled clinical trial

  2. [ ] Exclude all studies which are non-experimental (cohort study, case-control study, before-after studies, case series, letters, reviews, etc.).

[2] POPULATIONS
  1. [ ] Include if patients were selected due to undergoing PSA in an Emergency Department.

  2. [ ] Exclude papers where the patients were classified as: inpatients, day surgery patients, or endoscopy suite patients.

[3] INTERVENTIONS
  1. [ ] Include all primary research in which patients were monitored with capnography and standard monitoring (BP cuff, oxygen saturation, cardiac monitoring) versus standard monitoring only.

  2. [ ] Exclude if capnography was not the primary research question.

[4] OUTCOMES
  1. [ ] Must have clinically relative outcomes (i.e. airway intervention required, hypotension, oxygen desaturation, CO2 levels).

  2. [ ] Exclude all studies that do not report clinically relevant outcomes.

[5] FINAL DECISION
  1. [ ] INCLUDED (meets inclusion criteria above)

  2. [ ] NOT INCLUDED

  3. [ ] CAN'T TELL (need more information from authors to make decision

Appendix 3. Studies meeting inclusion criteria

Unique IDStudy ID (Lead Author, year)PMIDSource (Journal, conference, etc)
1   
2   
3   

Appendix 4. Data Extraction Form

 

Review title or ID
     
Study ID (surname of first author and year first full report of study was published e.g. Smith 2001)
     
Report IDs of other reports of this study (e.g. duplicate publications, follow-up studies)
     

Notes:        

 

 

 

1.     General Information

Date form completed (dd/mm/yyyy)     
Name/ID of person extracting data

     

 

Report title

(title of paper/ abstract/ report that data are extracted from)

     

 

Report ID

(ID for this paper/ abstract/ report)

     

 

Reference details

  

 

Report author contact details

     

 

Publication type

(e.g. full report, abstract, letter)

     

 

Study funding sources

(including role of funders)

     

 

Possible conflicts of interest

(for study authors)

     

 

Notes:      

3.     Population and setting

 

Description

Include comparative information for each group (i.e. intervention and controls) if available

Location in text

(pg/fig/table)

Population description

(from which study participants are drawn)

          

Setting

(including location and social context)

          
Inclusion criteria          
Exclusion criteria          
Method of recruitment of participants          
Informed consent obtainedYes     No    Unclear          
Notes:  

4.     Methods

 

Descriptions as stated in report/paper

 

Location in text

(pg/fig/table)

Aim of study          
Design (e.g. parallel, crossover, cluster)          

Unit of allocation

(by individuals, cluster/ groups or body parts)

          
Start date  
End date     
Total study duration           
Ethical approval needed/ obtained for studyYes     No    Unclear          
Notes:   

6.     Participants

Provide overall data and, if available, comparative data for each intervention or comparison group.

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Total no. randomized

(or total pop. at start of study for NRCTs)

          

Clusters

(if applicable, no., type, no. people per cluster)

          
Baseline imbalances          

Withdrawals and exclusions

(if not provided below by outcome)

          
Age          
Sex          
Race/Ethnicity          
Severity of illness          
Co-morbidities            
Other treatment received (additional to study intervention)          
Other relevant sociodemographics            
Subgroups measured            
Subgroups reported            
Notes:       

7.     Intervention groups

Copy and paste table for each intervention and comparison group

Intervention Group 1

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Group name            

No. randomized to group

(specify whether no. people or clusters)

          
Theoretical basis (include key references)           
Description (include sufficient detail for replication, e.g. content, dose, components)          
Duration of treatment period          
Timing (e.g. frequency, duration of each episode)          
Delivery (e.g. mechanism, medium, intensity, fidelity)          

Providers

(e.g. no., profession, training, ethnicity etc. if relevant)

          
Co-interventions           
Economic variables
(i.e. intervention cost, changes in other costs as result of intervention)
          

Resource requirements to replicate intervention

(e.g. staff numbers, cold chain, equipment)

          
Notes:         

8.     Outcomes

Oxygen Desaturation

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Outcome name           
Time points measured          
Time points reported          
Outcome definition (with diagnostic criteria if relevant)          
Person measuring/reporting          

Unit of measurement

(if relevant)  

          
Scales: upper and lower limits (indicate whether high  or low score is good)          
Is outcome/tool validated?Yes     No    Unclear          
Imputation of missing data
(e.g. assumptions made for ITT analysis)
          

Assumed risk estimate

(e.g. baseline or population risk noted  in Background)

          
Power          
Notes:         

 

Hypotension

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Outcome name           
Time points measured          
Time points reported          
Outcome definition (with diagnostic criteria if relevant)          
Person measuring/reporting          

Unit of measurement

(if relevant)  

          
Scales: upper and lower limits (indicate whether high  or low score is good)          
Is outcome/tool validated?Yes     No    Unclear        
Imputation of missing data
(e.g. assumptions made for ITT analysis)
          

Assumed risk estimate

(e.g. baseline or population risk noted  in Background)

          
Power          
Notes:         

 Airway Intervention Performed

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Outcome name           
Time points measured          
Time points reported          
Outcome definition (with diagnostic criteria if relevant)          
Person measuring/reporting          

Unit of measurement

(if relevant)  

          
Scales: upper and lower limits (indicate whether high  or low score is good)          
Is outcome/tool validated?Yes     No    Unclear          
Imputation of missing data
(e.g. assumptions made for ITT analysis)
          

Assumed risk estimate

(e.g. baseline or population risk noted  in Background)

          
Power          
Notes:         

Emesis/Aspiration

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Outcome name           
Time points measured          
Time points reported          
Outcome definition (with diagnostic criteria if relevant)          
Person measuring/reporting          

Unit of measurement

(if relevant)

 

          
Scales: upper and lower limits (indicate whether high  or low score is good)          
Is outcome/tool validated?Yes     No    Unclear          
Imputation of missing data
(e.g. assumptions made for ITT analysis)
          

Assumed risk estimate

(e.g. baseline or population risk noted  in Background)

          
Power          
Notes:  

 Recovery Time

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Outcome name           
Time points measured          
Time points reported          
Outcome definition (with diagnostic criteria if relevant)          
Person measuring/reporting          

Unit of measurement

(if relevant)

 

          
Scales: upper and lower limits (indicate whether high  or low score is good)          
Is outcome/tool validated?Yes     No    Unclear          
Imputation of missing data
(e.g. assumptions made for ITT analysis)
          

Assumed risk estimate

(e.g. baseline or population risk noted  in Background)

          
Power          
Notes:  

9.     Results

Copy and paste the appropriate table for each outcome, including additional tables for each time point and subgroup as required.

 

Dichotomous outcome

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Comparison          
Outcome          
Subgroup          
Timepoint
(specify whether from start or end of intervention)
          
Results Intervention Comparison     
No. eventsNo. participantsNo. eventsNo. participants
                    
No. missing participants and reasons               
No. participants moved from other group and reasons               
Any other results reported          
Unit of analysis (by individuals, cluster/groups or body parts)           
Statistical methods used and appropriateness of these methods (e.g. adjustment for correlation)          
Reanalysis required? (specify)Yes     No    Unclear          
Reanalysis possible?Yes     No    Unclear          
Reanalysed results          
Notes:         

 

Continuous outcome

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Comparison          
Outcome          
Subgroup          
Timepoint
(specify whether from start or end of intervention)
          
Post-intervention or change from baseline?          
Result Intervention Comparison 
MeanSD (or other variance)No. participantsMeanSD (or other variance)No. participants     
                              
No. missing participants and reasons               
No. participants moved from other group and reasons               
Any other results reported           

Unit of analysis

(individuals, cluster/ groups or body parts)

          
Statistical methods used and appropriateness of these methods (e.g. adjustment for correlation)          
Reanalysis required? (specify)Yes     No    Unclear          
Reanalysis possible?Yes     No    Unclear          
Reanalysed results          
Notes:          

 

Other outcome

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Comparison          
Outcome          
Subgroup          
Timepoint
(specify whether from start or end of intervention)
          
ResultsIntervention resultSD (or other variance)Control resultSD (or other variance)     
                    
Overall resultsSE (or other variance)
          
No. participantsInterventionControl 
          
No. missing participants and reasons               
No. participants moved from other group and reasons               
Any other results reported          
Unit of analysis (by individuals, cluster/groups or body parts)          
Statistical methods used and appropriateness of these methods          
Reanalysis required? (specify)Yes     No    Unclear          
Reanalysis possible?Yes   No    Unclear          
Reanalysed results          
Notes:        

 

10. Applicability

 

Have important populations been excluded from the study? (consider disadvantaged populations, and possible differences in the intervention effect)

          

Yes     No    Unclear

     
Is the intervention likely to be aimed at disadvantaged groups? (e.g. lower socioeconomic groups)

          

Yes     No    Unclear

     

Does the study directly address the review question?

(any issues of partial or indirect applicability)

          

Yes     No    Unclear

     
Notes:         

 

11. Other information

 

 

Description as stated in report/paper

 

Location in text

(pg/fig/table)

Key conclusions of study authors            
References to other relevant studies           
Correspondence required for further study information (from whom, what and when)     
Notes:  

Appendix 5. Risk of Bias Assessment

Domain Risk of bias

Support for judgement

 

Location in text

(pg/fig/table)

Low riskHigh riskUnclear

Random sequence generation

(selection bias)

             

Allocation concealment

(selection bias)  

             

Blinding of participants and personnel

(performance bias)

   

Outcome group: All/     

     

     

Blinding of outcome assessment

(detection bias)

   

Outcome group: All/     

     

     

Incomplete outcome data

(attrition bias)  

             

Selective outcome reporting?

(reporting bias)

             
Other bias               
Notes:       

Contributions of authors

Brian F Wall (BFW), Kirk Magee (KDM), Samuel G Campbell (SGC), Peter J Zed (PJZ)

Conceiving the review: BFW, KDM, PJZ

Co-ordinating the review: BFW, KDM

Undertaking manual searches: BFW, KDM

Screening search results: BFW, KDM

Organizing retrieval of papers: BFW

Screening retrieved papers against inclusion criteria: BFW, KDM, SGC

Appraising quality of papers: BFW, KDM

Abstracting data from papers: BFW, KDM

Writing to authors of papers for additional information: BFW

Providing additional data about papers: BFW

Obtaining and screening data on unpublished studies: BFW

Data management for the review: BFW, KDM

Entering data into Review Manager (RevMan 5.2): BFW, KDM

RevMan statistical data: BFW, KDM

Other statistical analysis not using RevMan: BFW, KDM

Interpretation of data: BFW, KDM, PJZ

Statistical inferences: BFW, KDM, PJZ

Writing the review: BFW, KDM, PJZ

Securing funding for the review: BFW, KDM

Performing previous work that was the foundation of the present study: SGC, PJZ

Guarantor for the review (one author): BFW

Person responsible for reading and checking review before submission: KDM

Declarations of interest

Brian F Wall: none known

Kirk Magee: none known

Samuel G Campbell: none known

Peter J Zed: none known

Sources of support

Internal sources

  • No sources of support supplied

External sources

  • Canadian Association of Emergency Physicians (CAEP) Research Grant, Canada.

    A national grant competition was won providing financial support to pay for statistician services and reference software.

Ancillary