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YOUTH SMOKING INHONG KONGLam TH, Ho SY, Lai MK

Department of Community Medicine,Faculty of Medicine,

The University of Hong Kong

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Introduction

• 3 Youth Smoking Surveys commissioned by the Hong Kong Council on Smoking and Health in 1994, 1999 and 2003

• Study smoking prevalence, factors associated with smoking, respiratory symptoms, quitting

• Monitor smoking trends

• Incorporated the Global Youth Tobacco Survey in the 2003 survey

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Methods

• Two-stage cluster sampling– Territory-wide non-international secondary schools

were randomly selected– 2 classes from each of form1 to form 3 were further

selected randomly

• All students in selected classes completed a self administered, anonymous and structured questionnaire in the classroom in the absence of teachers

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Participants

• 1994: 6304 students from 61 schools

• 1999 vs 1994: 8737 vs 4539 students from the same 45 schools

• 2003: 40840 students from about 90 schools by mid 2004 (8863 Form 1 students surveyed in 1999 are followed up)

• (2003 survey in progress. 1994 and 1999 results will be presented)

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Cough & Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Int J Epidemiol 1998;27(1):41-8.

3.02

2.71

2.9

1.56

2.77

2.86

2.52

2.15

1.88

2.13

2.66

1.98

1.12

1.36

1.29

1

1

1

0 1 2 3 4

Cough, past 3months

Cough, evening

Cough, morning

Adjusted Odds Ratio

Never smokerTried onlyUsed to, not nowSmoked <1/weekSmoked 1-6/weekSmoked >6/week

p for trend < 0.001

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Phlegm & Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Int J Epidemiol 1998;27(1):41-8.

3.91

4.84

3.95

1.46

3.92

2.87

1.72

2.11

1.42

2.01

2.4

2.11

1.2

1.62

1.39

1

1

1

0 1 2 3 4 5 6

Phlegm, past 3months

Phlegm, day ornight

Phlegm,morning

Adjusted Odds Ratio

Never smokerTried onlyUsed to, not nowSmoked <1/weekSmoked 1-6/weekSmoked >6/week

p for trend < 0.001

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Throat problems / Wheezing & Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Int J Epidemiol 1998;27(1):41-8.

2.91

2.1

2.23

3.48

2.34

1.89

1.94

1.39

1.52

1.88

1.77

1.6

1.27

1.35

1.19

1

1

1

0 1 2 3 4

Wheezing, past3 months

Wheezing, ever

Throatproblems

Adjusted Odds Ratio

Never smokerTried onlyUsed to, not nowSmoked <1/weekSmoked 1-6/weekSmoked >6/week

p for trend < 0.001

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Cough & Passive Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Int J Epidemiol 1998;27(1):41-8.

0.94

2.23

1.41

1.61

1.62

1.64

0.92

1.32

1.08

1

1

1

0 1 2 3

Cough, past 3months

Cough, evening

Cough, morning

Adjusted Odds Ratio

No smokerOne smokerTwo smokers>= 3 smokers

p for trend < 0.001 (except cough, past 3 months)

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Phlegm & Passive Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Int J Epidemiol 1998;27(1):41-8.

1.63

2.29

1.87

1.35

1.39

1.82

1.14

1.19

1.12

1

1

1

0 1 2 3

Phlegm, past 3months

Phlegm, day ornight

Phlegm,morning

Adjusted Odds Ratio

No smokerOne smokerTwo smokers>= 3 smokers

p for trend < 0.005 (except phlegm, past 3 months, p = 0.03)

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Throat Problems / Wheezing & Passive Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Int J Epidemiol 1998;27(1):41-8.

1.77

1.41

1.52

1.44

1.17

1.89

1.21

1.18

1.31

1

1

1

0 1 2 3

Wheezing, past3 months

Wheezing, ever

Throatproblems

Adjusted Odds Ratio

No smokerOne smokerTwo smokers>= 3 smokers

p for trend < 0.05 for throat problems only

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Factors Associated withEver Smoking

* Adjusted for age, gender, area of residence and type of housing

Source: Lam, et al. Am J Prev Med 1998;14(3):217-23.

1.91

2.08

2.68

1.24

1

1

1

1

0 1 2 3

Wrong knowledgeabout

health hazards ofsmoking

Positive attitudestoward smoking

Perception of cig.ads

as attractive

Participated in cig.promotion

or sponsoredactivities

Adjusted Odds Ratio

NoYes

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Overestimation of Smoking Prevalence in Adolescents

• Overestimation predicts smoking initiation and associated positively with future smoking in the West.

• 1999 COSH Survey: Out of 100 students of your age in Hong Kong, how many of them smoke cigarettes? (1 / 5 / 10 / 15 / 20 / 25 / 30 / 35 / 40 or above / Don't know)

• Students who overestimated their age-specific smoking rate were classified as overestimation.

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Overestimation ofSmoking Prevalence

18.920.6

17.215.918.5

13.4

18.2 18.1 18.3

47.1

42.9

51.1

0.0

10.0

20.0

30.0

40.0

50.0

60.0

Overall Boys Girls

Per

cent

age

Don't know Accurate or underestimationOverestimation Grossly overestimation 2x

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Odds Ratios of Smoking by Overestimation in Boys

* Adjusted for age, gender, area of residence, type of housing, etc.

2.29

2.37

2.1

1.76

3.52

1.17

1.36

1.24

1.25

2.38

1.4

1.84

1.15

1.02

1.95

1

1

1

1

1

0 1 2 3 4

Smoke when grownup

Smoke within thenext year

Smoke when offeredcigarettes

Ever smoker

Current smoker

Adjusted Odds Ratio

Accurate orunderestimation

Don't know

Overestimation

Grosslyoverestimation

p for trend < 0.05 except ever smoker

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18

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Intention to Quit Smoking

48.5

60.3 59.9

51.5

39.7 40.1

78.1

85.8

78.6

21.9

14.2

21.4

0

20

40

60

80

100

<1 cig. perweek

1 to 6 cig.per week

>6 cig. perweek

<1 cig. perweek

1 to 6 cig.per week

>6 cig. perweek

Per

cent

age

1994 Survey1999 SurveyWant to quit

Don't want to quit

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2003 YSS

• Incorporated items from the questionnaires of previous YSS survey the GYTS survey

• Standardised questionnaire, questionnaire administration, procedures and data analyses

• A cross-sectional and prospective study

• By January 2004, about 30000 questionnaires from 68 schools have been collected

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Conclusions

• The prevalence of smoking in youth has been increasing.

• Adverse health effects of smoking and passive smoking are found with high excess risks in Hong Kong.

• Many avoidable risk factors of smoking are identified.

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Conclusions

• A regular series of smoking surveys using standardised methods are essential to study risk factors and adverse effects of smoking and to monitor trends.

• Such surveys should be done more frequently.

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Youth Smoking Prevention (YSP)

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Download

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• Voluntary or self regulation

• Health education: on risks

• Banning of sales to minors

• Youth Smoking Prevention (YSP) (130 YSP programmes in more than 70 countries) funded by tobacco industry

(www.bat.com)

Interventions Supported bythe Tobacco Industry

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究底尋真

煙草業防止青少年吸煙計劃之真相

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Introduction• Published by World Health Organization

• The Traditional Chinese version is translated and published by HK Council on Smoking & Health

• The tobacco industry offered money, expert consultants and support services to governments and civic organizations– Japan, Philippines, Australia, Malaysia etc.

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• Comprehensive multisectional national tobacco control strategies, plans and programmes:

• Price and tax

• Protection from exposure to tobacco smoke

• Regulation of contents and disclosures of tobacco products

• Packaging and labelling (50% or more areas)

• Education, communication, training and public awareness

WHO Framework Convention 2003:

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• Comprehensive ban of advertising, promotion and sponsorship

• Cessation and treatment for tobacco dependency• Elimination of illicit trade• Prohibit sales to and by minors• Economically viable alternatives• Liability: criminal and civil• Research, surveillance, exchange of information• Cooperation

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WHO Framework Convention

Has your country signed?

What has been done?

What will be done?