a review of the evidence of quit-lines: gaps in the evidence and how to close them

A review of the evidence of quit-lines: gaps in the

evidence and how to close them

Dr Lion ShahabCRUK Health Behaviour Research CentreDepartment of Epidemiology & Public HealthUniversity College London

[email protected]

Overview

I. Why - the case for quitlines

II. What - evidence for the efficacy of quitlines

III. Where to – future questions to be answered

IV. How - state of the art in assessing smoking cessation interventions

Goals of Tobacco Control

To reduce the harm caused bytobacco use

To reduce participation in tobaccouse

To reduce the harmfulness oftobacco use

Reduce uptake

Increase cessation

I. Why – the case for quitlines

Approaches to Tobacco Control

Slama, 2004

Legislation & Policy

Basic Research Public Awareness

Values

Intervention Programmes





Reduce uptake

Increase cessation

Goals of Tobacco Control




Reduce uptake

Increase cessation


Predicted death-toll520500

340

0

100

200

300

400

500

1950 1975 2000 2025 2050Year

Cu

mu

lati

ve

to

ba

cc

o-r

ela

ted

de

ath

s (

mill

ion

s)

Current trend Uptake of smoking halved by 2020 Consumption halved by 2020


Approaches to Tobacco Control – Impact on Prevalence

Low Reach High

Low

E

ffic

acy

H

igh

Number of people quitting

Efficacy x Reach = Impact on Prevalence


Low Reach High

Low

E

ffic

acy

H

igh

Approaches to Tobacco Control – Impact on Prevalence


Basic Research Public Awareness

Values

Legislation & Policy

Intervention Programmes

Advantages of quitlines

• Potential high efficacy– Can emulate individual counselling delivered on-site in smoking

cessation services– Flexibility of application – stand alone, or as addition to online

interventions, minimal/leaflet interventions or face-to-face support

• Potential wide reach– Easy access for users (flexible and near universal coverage)– Can attract additional smokers who would not normally seek help:

those living in remote areas, with physical disabilities, those fearing stigmatisation

• Cheaper than other high-intensity interventions– Possibility of computerised delivery


Smokers

39 % Attempt to quit1

21 % use treatment1 18 % go ‘cold turkey’1

12 % buy NRT1 6 % get a prescription1 2.3 % use clinic1

Success 8 % 8% 15 % 11 % 4%Rates2

1 % + 0.5 % + 0.35 % + 0.08 % + 0.72

= 2.65 % stop smoking

Sources:

1 Smoking Toolkit Study

2 Cochrane Database

The path to smoking cessation

60 % Want to quit1

0.7 % use quitline1


0.08% of 8.500.000 smokers = 6.800 ex-smokers ~ 15.000 life-years saved yearly

Telephone counselling for smokingcessation – a Cochrane review (2009)

• Types of telephone counselling– Proactive vs Reactive– Stand-alone vs Adjunctive

• RCT, quasi-randomised control trials• 6-months abstinence• 65 studies included with sample size of 73,000

participants


• Study characteristics– Mostly from North America (52)– Older adults (average age 40)– Most evaluated proactive counselling (60)– Wide range of number of calls (1-12)– Call duration similar (10-20 min)– Mostly delivered by trained HP/counsellors



• Reactive telephone counselling– Single call

• Self-help vs. telephone counselling (1)• Different interventions (general vs. target) (2)

– Multiple calls• Reactive counselling at first call + self-help vs. further proactive

calls (9)



• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)



• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)– Multiple phone calls + brief intervention/counselling vs.

brief intervention/counselling alone (9)




brief intervention/counselling alone (9)– Multiple phone calls + pharmacotherapy vs.

pharmacotherapy along (9)





pharmacotherapy along (9)– Comparisons by different counselling intensities

• 1-2 (9); 3-6 (28); 7+ (7)



Counselling intensity

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1-2 3-6 7+

Number of sessions

Ris

k r

ati

o



pharmacotherapy along (9)– Comparisons by different counselling intensities

• 1-2 (9); 3-6 (28); 7+ (7)

– Comparison by motivation to stop smoking• Smokers recruited for motivation (14) or not (30)



Impact of motivation

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

Motivation required Motivation not required

Recruitment criterion

Ris

k r

ati

o

• Review provides good evidence for effectiveness of telephone counselling



Type of counselling Evidence

Reactive Single call

Additional proactive support

Proactive Vs. self-help/minimal

Adjunct to behavioural support

Adjunct to pharmacotherapy

?

?

• Review provides good evidence for effectiveness of telephone counselling

• The more intensive, the better• No difference by motivation of smokers



Remaining empirical uncertainties

• Is reactive telephone counselling effective?

• What is the ideal number of proactive sessions?

• How best to increase uptake of telephone counselling?



• Is reactive telephone counselling effective?– Problems: can’t use ‘pure’ RCT– What is appropriate control condition?– Elicit further calls?


Control (Self-help)

Intervention (generic)

Intervention (tailored)

1837

1837

1837


• What is the ideal number of proactive sessions?– Problem: Have to make a priori assumptions about

cost-effectiveness– NNT=100 at £100 (1 %) assumed to be cost-effective at

QALY of £3000 (5 times better than average medical treatment)


1 session (£50)

2 sessions (£100)

3 sessions (£150)

4 sessions (£200)

NNT=400

NNT=200

NNT=100

NNT=50


• How best to increase uptake of telephone counselling?– Enormous benefits


165 mil. smokers Attempt 66 mil. smokers Use QL 16.5 mil. Stop 1.8

Would safe 242.000 human beings from disability and early death


• How best to increase uptake of telephone counselling?– Enormous benefits– Use of mass media and development of closer

relationship with health care system– Displaying phone numbers on tobacco or smoking

cessation products– Best assessed with quasi-experimental or RCT design





Before After

Use

of

quit

-lin

es

Country A

Country B

Mass media campaign in Country B only

Net change




Control (no info on QL)

Treatment (info on QL)

Control (NRT)

Treatment (NRT+ QL number)

Remaining methodological uncertainties

• Studies often did not provide information on adequate randomisation or allocation concealment

• Abstinence was not consistently validated and many used point-prevalence

• Studies were underpowered

IV. How - assessing smoking cessation interventions

10 common issues

1. inappropriate research question2. inadequate sample size3. inappropriate sample4. inadequate recruitment rate5. inappropriate study design6. poorly specified intervention and control7. inadequate implementation8. weak outcome measure9. failure to address potential bias10. over-claiming from the results


Key areas to consider

• Study sample• Study design• Outcome assessment


Study Sample

Priorities to be balanced• generalisation to

population of interest• safety• cost• practicability• red tape

Options to discuss• settings

– General practice– University– Community– Other

• size• method of recruitment• exclusion and inclusion

criteria


Study design

Priorities• internal validity• generalisation• practicability

Options to discuss

• design type– RCT (double-blind vs. unblinded)– Cluster randomised trial– Fractional factorial design– Quasi-experimental study– Longitudinal study– Cross-sectional survey

• intervention

• comparison condition(s)0

10

20

30

40

50

60

70

Wave 3 Wave 5 Wave 3 Wave 5

Pro

po

rtio

n o

f all

CD

TS

+ att

em

pte

rs (

%)

NRT use

NRT obtained OTC*

CC^UK

468 415111 99

9181

59

24

81

58

26

4 2

97

94

0

20

40

60

80

100

35 50 60 70 80 90 100

Age (Years)

% A

live

Cigarette smokers

10 years


The problem of causality

• Direction: Stay middle class to avoid schizophrenic episodes!?

• Higher order variables: If you want to live long, eat breakfast!?

Socioeconomic Status Schizophrenia

Breakfast Longevity

Smoking Behaviour


Outcome assessment

Priorities• theoretical significance• clinical significance• practicability

Options to discuss• smoking status• motivation to smoke• withdrawal symptoms


Some principles: sample

• always base size on ≥80% power for what would be a meaningful effect size (usually 1-5% difference in pivotal trials, i.e. those that will form basis for recommendations)

• usually use dependent smokers (not students)• recruit from community or healthcare settings• minimise exclusion criteria in pivotal trials, allow for up

to 50% wastage


Some principles: design

• where ethical and practicable use RCT but not at the expense of getting a sensible answer

• do not overcomplicate with too many factors• consider fractional factorial designs when trying to

deconstruct multi-component interventions


Some principles: outcome assessment

• pivotal studies require ≥6 months’ follow-up• use self-report of continuous abstinence verified by CO• do not use reduction• use intent to treat• aim for at least 70% follow-up rate• for withdrawal symptoms and craving use MPSS or

MNWS0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50

Weeks since quit date

Per

cen

t of q

uit

atte

mp

ters

Cumulative abstinence Long-term success in continuous abstainers at given week Relapse risk in given week

0

2

4

6

8

10

No COPD COPD

Mis

rep

ort

ing

sm

okin

g s

tatu

s (

%)

Location of filter vent holesLocation of filter vent holes outside ISO testing machine


http://www.bmj.com/content/vol328/issue7444/images/large/smoke11.f5.jpeg

Further reading

• Stead, L. F., Perera, R., & Lancaster, T. (2006). Telephone counselling for smoking cessation. Cochrane Database Syst.Rev., 3, CD002850.

• Borland, R. & Segan, C. J. (2006). The potential of quitlines to increase smoking cessation. Drug Alcohol Rev., 25, 73-78.

• West, R., et al., Outcome criteria in smoking cessation trials: proposal for a common standard. Addiction, 2005. 100(3): p. 299-303.

• Shiffman, S., R. West, and D. Gilbert, Recommendation for the assessment of tobacco craving and withdrawal in smoking cessation trials. Nicotine Tob Res, 2004. 6(4): p. 599-614.

• Strecher, V.J., et al., Web-based smoking-cessation programs: results of a randomized trial. Am J Prev Med, 2008. 34(5): p. 373-81.

Any questions?

a review of the evidence of quit-lines: gaps in the evidence and how to close them

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