Trusted evidence.Informed decisions.Better health.

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Moving Cochrane evidence into practice: past, present & futureNicola Lindson-Hawley & Jamie Hartmann-BoyceManaging Editors

Cochrane Tobacco Addiction GroupNuffield Department of Primary Care Health SciencesUniversity of Oxford

9th June 2016UKNSCC 2016London, UK

@cochraneTAG

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What we will cover

01 What is Cochrane

02 What is the Cochrane Tobacco Addiction Group (CTAG)

03 The impact of CTAG

04 How to use and interpret Cochrane evidence

05 Where should CTAG focus their efforts in future?

06 How should we disseminate to our users?

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Cochrane Organisation named after Archie Cochrane

Chalmers, Chalmers and Enkin built on Archie’s work - summarised

all the RCT data relating to the care of pregnant women

Published as ‘Effective Care in Pregnancy and Childbirth’ (Keirse,

Grant et al. 1989)

Revolutionised perinatal care and led to the formation of the

Cochrane Collaboration in 1993

Archie believed that there wasn’t

enough evidence to justify most

clinical practice and championed the

use of randomised controlled trials

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CochraneWHAT?

Gathers and combines the best evidence from

research to determine the benefits and risks of

treatments/interventions

HOW?

By systematically reviewing the available

evidence, with strong emphasis on quality

assessment

WHY?

To help healthcare providers, patients, carers, researchers, funders,

policy makers, guideline developers improve their knowledge and

make decisions

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Cochrane Protocol => Review => Update

53 topic specific Review Groups, including TAG

Worldwide- based in over 100 countries

Not-for-profit- largely government funded

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Tobacco Addiction Group (CTAG) Founded by GPs working in the Department of Public Health at the

University of Oxford (C.Silagy, T.Lancaster, G.Fowler)

The group carried out one of the first trials of nicotine patches in

primary care

They met Iain Chalmers, who was establishing Cochrane, and

carried out a prototype review of NRT for smoking cessation

Established CTAG in 1996, making 2016 our 20th anniversary

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Tobacco Addiction Group (CTAG) Main focus on interventions for tobacco

use & prevention

Manage approx. 90 reviews & 350 authors

Based at the University of Oxford in the

Primary Care Department

Funded by the National Institute for Health Research (NIHR)

@cochraneTAG

Jamie Hartmann-Boyce

Managing Editor

Nicola Lindson-Hawley

Managing Editor

Lindsay Stead

Information Specialist Tim Lancaster

Co-ordinating Editor

Paul Aveyard

Editor, University of Oxford

Robert West

Editor, University College London

John Hughes

Editor, University of Vermont

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CTAG’s aims

To inform tobacco control policy

internationally

to inform research in tobacco control,

and help ensure new research is

focussed on important unanswered

questions

to contribute to reducing tobacco use

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Example review: NRTInfluencing

healthcare

guidance

Influencing

treatment

availability

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Recent evidence: e-cigarettes It is important that TAG reviews move with the times

The recent publication of the first version of our e-cigarette review

was an example of this (McRobbie et al. 2014)

Highlighted the lack of high quality research in the area- only 2 RCTs

met the inclusion criteria!

Received publicity worldwide,

following press release &

news briefing at the Science

Media Centre in London, UK

Due for update this year!

cochrane training

Using and interpreting

systematic reviews

cochrane training

• Sources of evidence

• How to access systematic reviews via the

Cochrane Library

• How to interpret systematic reviews (key

features)

• Quiz

In this session we’ll cover….

cochrane training

Where do you look for information?

cochrane training

Evidence based medicine resource pyramid

cochrane training

Why systematic reviews?

• efficient way to access the body of research

– saves time required for searching

– critical appraisal

– interpretation of results

• explore differences between studies

• reliable basis for decision making

– unbiased selection of relevant information

– useful for health care, policy, future research

cochrane training

Key components of a Cochrane review

cochrane training

Key stages of a systematic review

PROTOCOL

• clearly stated objectives

• pre-defined eligibility criteria

• explicit, reproducible methodology

• Search strategy

FULL REVIEW

• systematic search

• assessment of validity of included studies

• systematic synthesis and presentation of findings

cochrane trainingwww.thecochranelibrary.com

cochrane training

Accessing a review on the Library

cochrane training

• ParticipantsP

• InterventionsI

• ComparatorsC

• OutcomesO

• Study typeS

cochrane training

What is a forest plot?

Graphical display of

treatment effects from

multiple randomized

controlled trials. When

these are combined, it’s

called a meta-analysis.

cochrane training

Risk ratios (RR) in cessation reviews

For cessation, a risk ratio greater than 1 indicates that more people are quitting

in the intervention condition. For example, the below data gives us an RR of

1.5. A risk ratio of 1 means as many people quit in the control group as in the

intervention group.

Intervention

quit

Intervention

total

Control quit Control

total

15 100 10 100

RR = events in intervention group/participants in intervention group

events in control group/participants in control group

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• Summary of key information from review

• Most important outcomes for someone

making a decision

Summary of findings tables

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What is GRADE based on?

Quality of evidence in GRADE is based on 5 domains

Risk of bias

Inconsistency

Indirectness

Imprecision

Publication bias

The degree to which review

authors have judged each

included study to be at risk of

bias

Unexplained differences between

the results of individual studies

(heterogeneity). This can lead to

uncertainty about the underlying

effect.

Results can be downgraded because

of indirectness if:

1. Head to head comparisons are

not available

2. The population, intervention,

comparator or outcome is

different from the question the

review is trying to address

Results are considered imprecise if:

1. The total number of events is

small (usually less than 300)

2. The confidence intervals are wide

A systematic under or overestimate of

an effect due to selective publication

of studies. This can happen when the

results of a study are not reported. If,

for example, studies that detect an

effect are more likely to be published

than those with negative results, the

meta-analysis will be biased towards

positive results.

cochrane training

• Results based on trials - element of chance

• Each point estimate displayed with a

confidence interval (CI)

• CIs represented by the ends of the lines for

individual studies and by the horizontal edges

of the diamonds for pooled estimates.

• 95% CIs provide an estimated range of values

within which the true effect is 95% certain to

lie.

Each line represents an

individual study (or

intervention versus

control comparison)

The blue square

represents the point

estimate for the effect.

The size of the square is

dependent on the size of the study.

Bullen 2010 has 969 participants;

Rose 2006 96.

In this example, studies

are divided into

subgroups based on the

type of NRT.

Diamonds show a pooled

estimate, or the combined result

from all of the studies. Here,

there are pooled estimates for

studies in each subgroup and for

studies overall. This pooled

estimate represents the result of

the meta-analysis.

The vertical line is known as the line of no effect.

• For our cessation reviews, if the point estimate

is on the right side of the line, more people

receiving the intervention quit than people in

the control group. If the point estimate is on

the left side of the line, more people quit in the

control group than in the intervention group.

• If the confidence interval crosses this central

line, the effect is not statistically significant,

meaning it is possible that the intervention and

the control do not have different effects.

Stead LF, Perera R, Bullen C, Mant D, Hartmann-Boyce J, Cahill K, Lancaster T. Nicotine replacement therapy for smoking

cessation. Cochrane Database of Systematic Reviews 2012, Issue 11

cochrane training

• Get into small groups

• You have time to discuss

• You’ll be asked to share your answers

after each question

Quiz

cochrane training

How many of these studies have a statistically significant result?

a) none

b) One

c) Two

d) Three or moreAll of the studies have confidence intervals

that cross the line of no effect (1), so their

results aren’t statistically significant.

Q1

cochrane training

In how many studies did more people quit in the control group than in the

treatment group?

a) None

b) Two

c) Four

d) Seven

In four studies, the point estimate is to

the left of the line of no effect

Q2

cochrane training

• What risk ratio would you expect to see for this result?

• a) 0.5

• b) 1.0

• c) 1.5

Q3

Intervention

quit

Intervention

total

Control quit Control total

10 100 20 100

The risk ratio is less than one, because

more people quit in the control group

than in the intervention group

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Q4. What are the PICOs?

• ParticipantsP

• InterventionsI

• ComparatorsC

• OutcomesO

• Study typeS

• Individuals who smokeP

• CytisineI

• PlaceboC

• Continuous abstinence at longest follow-upO

• Randomized controlled trialsS

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Why was the evidence downgraded?

(can choose more than one answer)

a) Risk of bias

b) Inconsistency

c) Indirectness

d) Imprecision

e) Publication bias

The interventions being tested varied

considerably. In addition, there was

some evidence from a funnel plot to

suggest smaller studies that did not

detect significant results had not been

published.

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Cochrane TAG’s anniversary project

AIMS

Raise awareness of the group, and what we have

achieved so far

Identify areas where further research is needed in the

areas of tobacco control & smoking cessation by

involving our stakeholders

Identify specific goals for Cochrane TAG

Funded by the NIHR School for Primary Care Research

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Cochrane TAG’s anniversary projectStage 1: Identifying uncertainties survey

Asked anyone with an interest in tobacco to share the questions they

would still like to see answered by tobacco control research

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Cochrane TAG’s anniversary projectStage 2: Ranking uncertainties survey

1. E-cigarettes

2. Addressing

inequalities

Unanswered questions (uncertainties) were separated into 15

research categories, with each category consisting of 3-21

questions.

278 from the 1st survey contacted and asked to rank the 15

research categories in order of their importance. They were then

asked to rank the questions in their top 3

175 people completed the whole survey (63% of those invited)

3. Mental health

& other

substance abuse

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17th June we are holding a 1-day

workshop with 50 of our stakeholders

Discussion of where CTAG should focus

its future efforts and ways to disseminate

our findings

The findings of the project will be written

up, with our priorities & aims for the future,

and published

We will begin to work on the priorities

before the end of the year and will

continue to do so into the future

Cochrane TAG’s anniversary projectStage 3: Prioritisation Workshop

cochrane training

Any questions?

cochrane training

• Get into small groups (3-5) – choose a scribe who will feed back from each

• First 10 minutes: identify gaps in the tobacco control evidence base (see survey results if you need a steer)

• Second 10 minutes: Discuss the best ways Cochrane can get information to you

• Final 10 minutes: Feedback and discussion

Workshop

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How to find out more or contact us

Visit our website: http://tobacco.cochrane.org/

Tweet us: @cochraneTAG

Email us: nicola.lindson-hawley@phc.ox.ac.uk

Call us: +44 (0)1865 289 320