Christopher Eccleston

Christopher Eccleston

Centre for Pain Research

The University of Bath

c.eccleston@bath.ac.uk

Order of service

• Cochrane Collaboration• Methods• Communication• Methods Development• Other

Cochrane Collaboration

• Founded in 1993 Iain Chalmers• Following Archie Cochrane• Principles of Evidence for all• 52 CRGs• Centres & Fields• Volunteer• Consumerist• Quality• Control over Bias• Living Library

Cochrane Collaboration Review GroupPain, Palliative & Supportive Care

PaPaS

• http://papas.cochrane.org

• Established in 1998• Based in Oxford• Updates 2 years• Cochrane Database

Systematic Reviews• The Cochrane Library• Field Editors

Current Status• Editorial Board

– Mike Bennett– Andrew Moore– Tim Steiner– Amanda Williams– Acute Pain Vacancy

• Title to Protocol to review

• 120 reviews• 70 protocols and titles• 2 overviews• IASP SIG Systematic Reviews• ACTINPAIN Writing Group

Quality improvement (Actinpain)

Methods• Guidance?• Common Methods• RevMan (free)• Supported (Title Reg)• Professional Searching• Published Protocols• International (not English)• Meta-analysis• Bias Control• Communication

www.cochrane-handbook.org/

Features

• Standard description of condition/intervention

• Full description of studies (Tables)

• Assessment of heterogeneity– Clinical pooling like with unlike– Statistical (small n)

• Sub-group analyses– (dose)

Meta-analysis +

• Effect sizes• Forest plots• Assumptions

– Fixed effects• Assume variation is

sampling error

• Violations– Heterogeneity– Small n

• Junk in Junk out– Quality of primary

Communication

• Abstracting

• Plain Language Summary

• Risk of Bias Tool

• Summary of Findings

• Podcast

• Journal Club

• PICO

Risk of Bias

Summary of Findings

Guyatt GH, Oxman AD, Vist GE, Kunz R, Falck-Ytter Y, Alonso-Coello P, Schünemann HJ; GRADE Working Group. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008 Apr 26;336(7650):924-6.

The GRADE system classifies the quality of evidence in one of four grades:

GRADE DEFINITION

High

⊕⊕⊕⊕Further research is very unlikely to change our confidence in the estimate of effect.

Moderate

⊕⊕⊕

Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.

Low

⊕⊕

Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.

Very Low

⊕

Any estimate of effect is very uncertain.

Journal Club

Methods 1: Outcomes

• Use outcomes (IMMPACT) chronic• Pain reduction: 30% moderate, 50% Good• Other

– Time to re-medication– non-pain outcomes

• Not recommended– Odds ratios– Analgesic consumption

• No use of group means– Pain relief has a U shaped distribution– Response analysis on dichotomous data

• Adverse events

Core outcomes

Methods 2: ROB

• Use of quality rating scales?

• Jadad scale• Non-pharmacological

interventions?

PaPaS RAG

Methods 3: GRADE

Alternative?

Methods 4: NNT

• Inverse of the absolute risk• Benefits

– Easier to understand– Compare between treatments easily

• Costs– More is worse– Can hide effect (EMEA Report)

• Never an NNT alone• RR, NNT, NNH, percentage improvement

Stabilizing a review

• Publication bias• Stabilizing (not updating)

Not discussed• Overclaiming

– No effective or no evidence of effect• Quality control in non-pharmacological trials• Language of confidence• Simplify vs simplistic (95% read abstract)• 30 or 50 or 70• Responder analysis vs response analysis• Does pain relief drive QoL outcomes?• Comparing treatments

– Overview reviews– Stopping rules, Switch rules– Indirect comparisons

• Judgement biases– Behavioural economics (choices)– Myth of rational man

Communication

• What is the risk doctor?

• Tell it to me straight.

• What are my chances doctor?

• Tell it to me straight.

Thank you