ORIGINAL PAPER

Increased Risk of Cigarette Smoking Among Immigrant Childrenand Girls in Hong Kong: An Emerging Public Health Issue

Maggie Lau • Xinguang Chen • Yuanjing Ren

Published online: 15 June 2011

� Springer Science+Business Media, LLC 2011

Abstract Despite global progress in tobacco control, data

are needed for subgroups with increased risk of tobacco use

for more effective smoking prevention. Survey data from a

random sample of 6,486 youth in grades 7, 8 and 9 were

derived from the project Chinese Student Health Survey.

Prevalence and hazards of smoking onset were compared

by gender and immigrant status. Mediation analysis was

used to assess factors that may mediate the impact of

immigrant status on smoking. Immigrant students had a

much higher risk of hazards of smoking initiation than non-

immigrant students. Parental monitoring and parental

smoking significantly mediated the effect of immigrant

status on early smoking onset. In addition, gender differ-

ences in the prevalence of smoking and hazards of smoking

onset in our study were smaller than those reported by

others targeting non-Hong Kong Chinese youth. Findings

of this study imply that immigrant children and girls in

Hong Kong are at increased risk to tobacco use. Special

attention should be paid to these subgroups for prevention

intervention. Prevention intervention for immigrant chil-

dren should address parental smoking and parental moni-

toring. Reduced gender difference in smoking among Hong

Kong youth suggests an emerging trend for more Chinese

girls on the Mainland to smoke along with the rapid

socioeconomic development.

Keywords Immigrants � Gender differences �Adolescent smoking � Hong Kong

Introduction

Despite global effort to control tobacco use since the

1950s, data from diverse sources indicate that smoking is

prevalent among adolescents, including youth in Hong

Kong [1–4]. Prevention of early onset of smoking is of

strategic significance to reduce adolescent smoking [5–9].

Early onset is one of the most influential factors that affect

the likelihood of sustained smoking [5, 6]. Like many other

substances, the developing brain of adolescents is vulner-

able to tobacco [10]. In addition to a number of negative

health consequences [1, 2, 11], early exposure to tobacco is

associated with sustained tobacco use during later adoles-

cence-adulthood [3, 10, 12].

Data on early initiation of tobacco use is of great sig-

nificance for smoking prevention intervention. Tobacco

researchers have documented the age pattern of hazards of

smoking initiation among Chinese adolescents in Mainland

China [5], which is similar to that observed among Chinese

adolescents in the United States [6]. Researchers have also

documented a number of factors associated with the like-

lihood of early smoking onset, such as gender [5, 8, 10],

immigrant status [13, 14], peer norm [15–17], parental

M. Lau (&)

Department of Social Sciences, The Hong Kong Institute

of Education, 10 Lo Ping Road, Tai Po, New Territories,

Hong Kong Special Administrative Region, China

e-mail: maggielau@ied.edu.hk

M. Lau

Action Health, Room 910-911, 9/F, Youth Square, 238 Chai

Wan Road, Chai Wan, Hong Kong Special Administrative

Region, China

X. Chen � Y. Ren

Pediatric Prevention Research Center, Wayne State University

School of Medicine, 4707 St. Antoine, Detroit,

MI 48201-2196, USA

e-mail: jimchen@med.wayne.edu

Y. Ren

e-mail: yre@med.wayne.edu

123

J Community Health (2012) 37:144–152

DOI 10.1007/s10900-011-9428-9

smoking [8, 12, 16–18], parental support and monitoring

[19–21], and depression [22, 23]. However, no study has

been conducted to assess to what extent these factors may

also affect adolescent smoking initiation in Hong Kong.

Hong Kong as a world financial hub has attracted a

substantial number of people from all over the world,

particularly those from the Mainland China along with the

increased pace of globalization [24] and immigration pol-

icy changes (such as introduction of One-way Permits or

OWP for family reunion). The resulting increased cross-

border socioeconomic interactions boosted cross-border

marriages and migration [25]. These migrant families

might have encountered difficulties in adaptation to new

working and living environment in Hong Kong [26]. Data

from diverse sources indicate that immigrant children in

Hong Kong may also be at increased risk of tobacco

smoking compared to non-immigrant children [27, 28].

Moving to Hong Kong and adaptation to local living may

have rendered children of these new comers at increased

risk for nonsmokers to start smoking and for smokers to

continue smoking. In addition to possible high rates of

smoking among immigrant parents, the lack of quality time

of these parents with their children [29], and emotional

problems in immigrant children [30] may add additional

risk for these children to smoking. A systematic exami-

nation of these factors, including potential mediating role

in mediation the effect between migration and smoking

onset among Chinese youth will provide evidence for more

effective tobacco prevention in Hong Kong.

Data from the Global Youth Tobacco Survey shows that

the difference in tobacco use between boys and girls is

narrower in different regions of the world [31]. Recent

studies also show smaller gender differences in tobacco use

among Asian population. Researchers also advocate that

there is a demand for gender-sensitive tobacco control

policies in this region [32, 33]. Previous studies indicate

that there are significant gender differences in hazards of

smoking initiation among Chinese adolescents with boys at

significantly greater probabilities to initiate smoking than

girls [5, 6]. It is valuable to explore whether differences in

patterns of tobacco use between boys and girls in the

Chinese societies, like Hong Kong, is declining along with

rapid socioeconomic changes.

The purposes of this study are fourfolds: (1) to describe

the age pattern of the hazards of smoking onset; (2) to

explore whether the hazards of smoking onset is greater for

boys than for girls; (3) to examine whether immigrant

students are at greater risk to start smoking early compared

to non-immigrant students; and (4) to analyze the differ-

ences in the hazard of smoking onset by immigrant status is

partially mediated through increased depression and

weakened parental monitoring. These data are highly

needed to understand subculture differences in tobacco use

and effective tobacco use prevention among youth in Hong

Kong.

Methods

Data Sources, Participants and Sampling Procedure

Data used for this analysis is part of a large scale collab-

orative research project—Chinese Student Health Survey

(CSHS) undertaken in Taiwan, Hong Kong, Macao, and

the Mainland China (http://www.projectcshs.org/). It is a

researchers-initiated effort to document health behaviors

and influential factors for health promotion among Chinese

youth. We used the data collected in Hong Kong for this

analysis. A cross-sectional and school-based survey tar-

geting secondary forms 1–3 (equivalent to grades 7–9 in

the United States) students in Hong Kong was conducted

during September–December, 2009. A two-stage cluster

sampling method was used to recruit study participants

representing all students in the three forms across the ter-

ritory. A full list of secondary school profiles was obtained

from the Education Bureau. All Aided, Caput, Direct

Subsidy Scheme, Government and Private secondary

schools were chosen and only the whole day and grammar

schools were included. A total of 459 eligible schools were

included as the sampling frame. 70 schools were randomly

selected from the frame based on probability proportionate

to school size sampling (i.e. total number of eligible stu-

dents) without replacement [34]. Before conducting the

survey, the researchers sent invitation letters to the sampled

schools which explained the purposes of the study. Even-

tually, 42 (60%) randomly sampled schools agreed to

participate. Among each participation school, one school

form was chosen using simple random digits method.

Students in all classes of the same school form of a selected

school were invited to participate in the survey. All stu-

dents were well-informed that participation in the survey is

absolutely voluntary, and they were offered rights not to

participate and to quit during any time of the survey. They

were also informed that no personal data will be released

and the collected data were used for statistical analysis

only.

The questionnaire was developed based on previous

studies among Chinese youth in China and the United

States [15, 35] and the Global School-based Student Health

Survey (GSHS) [36]. Revisions were made in language to

suit for students in Hong Kong. The drafted questionnaire

has been revised according to feedback from the key

investigators of CSHS. The finalized questionnaire con-

tains 50 questions with a brief introduction sheet to the

survey. It takes approximately 15–20 min for a typical

student to complete.

J Community Health (2012) 37:144–152 145

123

As the survey was anonymous, the trained data collec-

tors managed the survey in the classroom independently,

including the introduction to the students about the survey

and answering their questions. The data collectors sealed

the completed questionnaires in an envelope in front of the

students and sent to the researchers’ office for further

processing. A total of 6,586 completed questionnaires were

collected. After having excluded those invalid question-

naires, including no answer or inconsistent answers in the

questions related to smoking status, gender, and age, 6,468

questionnaires with valid data were included for this

analysis.

Variables and Their Measurements

Smoking Behavior

Participants were first asked ‘‘How old were you when you

first tried a cigarette?’’ The response options included:

0 = ‘‘I have never smoked cigarette’’, 1 B ‘‘7 years old’’,

2 = ‘‘8–9 years old’’, 3 = ‘‘10–11 years old’’, 4 = ‘‘12–13

years old’’, 5 = ‘‘14–15 years old’’, and 6 = ‘‘16 years old

or older’’. The reported age of first smoking was used to

assess the pattern of early onset of cigarette smoking using

the method of survival analysis, and to examine factors

associated with early age of smoking onset using the method

of proportional hazards regression (see the ‘‘Statistical

Analysis’’ section). Students who reported an age of first

smoking were also coded as ‘‘lifetime smokers’’. Students

were further asked the question: ‘‘During the past 30 days, on

how many days did you smoke cigarettes?’’ Those who

reported having smoked on at least 1 day in the past 30 days

were coded as ‘‘30-day smokers’’.

Parental Smoking

Students were asked to report whether their parents (both

father and mother/male and female guardians) were cur-

rently smoking with answer options (1 = ‘‘No’’,

2 = ‘‘Yes’’, 3 = ‘‘Don’t know’’, 4 = ‘‘passed away’’)

provided. A parent was coded as a smoker if the youth

responded positively to the question.

Parental Monitoring

A three-item scale from the GSHS [36] (Cronbach

a = 0.67) was used to measure parental monitoring. They

were (1) ‘‘during the past 30 days, how often did your

parents or guardians check to see if your homework was

done?’’, (2) ‘‘during the past 30 days, how often did your

parents or guardians understand your problems and wor-

ries?’’, and (3) ‘‘during the past 30 days, how often did

your parents or guardians really know what you were doing

with your free time?’’. They were assessed using a 5-point

likert scale with 1 = ‘‘Never’’ and 5 = ‘‘Always’’. Total

scores were computed for analysis by summing up item

scores such that higher scores indicating closer parental

monitoring.

Depression

Depressive symptoms were assessed using a four-item

scale (Cronbach a = 0.65) adopted by the GSHS [36].

They were (1) ‘‘during the past 12 months, how often have

you felt lonely?’’, (2) ‘‘during the past 12 months, how

often have you been so worried about something that you

could not sleep at night?’’, (3) ‘‘during the past 12 months,

have you ever stopped your daily activities for over

2 weeks because of feeling upset and desperate?’’ and (4)

‘‘during the past 12 months, did you ever seriously con-

sider attempting suicide?’’. The first two questions were

assessed using a 5-point scale (1 = Never, 2 = Rarely,

3 = Sometimes, 4 = Most of the time, 5 = Always). The

last two questions were assessed using two options

(1 = Yes, 2 = No). We reversely coded the responses to

these two items as 1 = 5 and 2 = 1 and used in computing

the total depressive symptoms scores. Total scores were

computed for analysis by summing up item scores such that

higher score indicating severe depressive symptoms.

Immigrant Status

All participants were asked where they were born. Since

students in each of non-Hong Kong-born groups (including

‘‘Mainland China’’, ‘‘Macao or Taiwan’’, and ‘‘elsewhere

outside Hong Kong’’) consist of only a small proportion of

the total sample, we combined them into one group as

‘‘immigrant students’’ and the rest as ‘‘non-immigrant

students’’.

Demographic and Other Covariates

Age (in years), gender (male vs. female), self-rated school

performance (from superior to inferior), and parental edu-

cational attainment (from no formal education to college or

above) were used to describe the study sample and to

include in multivariate analysis as covariates.

Statistical Analysis

Prevalence rates with 95% confidence interval (CI) were

computed for lifetime smoking and past 30-day smoking.

Differences in smoking prevalence rates by gender,

immigrant status, self-rated school performance (above and

below average), parental smoking, depression and parental

146 J Community Health (2012) 37:144–152

123

monitoring (above and below median) were compared

using chi-square test.

The hazard of smoking onset by age was estimated using

the survival analysis method [37, 38]. It was conducted by

a reconstructed birth cohort using the survey data as if all

the participants were followed from birth till the time (age)

when they participated in the survey, the reported age

of first smoking was thus modeled [5, 6]. The hazards of

smoking onset were estimated as the instantaneous rate of

smoking initiation at the beginning of a given age or age

group (time period). The numerator was the number of

persons who smoked the first time during a given period

(age range), and the denominator was the total number of

nonsmokers at the beginning of that period.

The PROC LIFETEST was used to estimate the hazards

of smoking onset by age using the data of the age at survey

and age when first smoked a cigarette. Since no data on

single year was collected to assess smoking onset, the

hazards of smoking onset were estimated using 2-year age

intervals with 6–7 years of age as the first group. Partici-

pants who reported having not yet smoked at the time of

survey were coded as ‘‘censored’’. Besides, the hazard

modeling analysis was conducted by gender and by

immigrant status to provide relevant information. The

differences in the hazards of smoking onset by age between

the comparison groups were assessed using log-rank test

[37, 38]. The plot of -log survival over time (age) and

log[-log(survival)] against log (time or age of onset) were

constructed to determine whether the distribution of the

hazard of smoking onset by age follows an exponential

Weibull model so that the data were appropriate for anal-

ysis using the survival analysis method [37, 38]. Pre-

liminary analysis of the data indicated a disproportionately

increase in hazards of smoking onset for participants at the

beginning of age 6, suggesting extra number of participants

reported smoking onset in the first open age group

(ages B 6). Since the youngest age of smoking onset

among Chinese youth from reported data was 4 [5], the

disproportionate increases in the hazards of smoking onset

at age 6 was smoothed between age 4 and 6 through visual

curve fitting.

To determine paternal smoking, maternal smoking,

parental monitoring and child depression in mediating the

association between immigrant status and early smoking

onset, we first associated immigrant status with these four

variables using logistic regression analysis, age and gender

were included as covariates. We then associated the four

factors with age of smoking onset using the proportional

hazards regression model [37, 38], gender, school perfor-

mance, and immigrant status were included as covariates.

Factors that were predicted by immigrant status and pre-

dicted age of smoking onset were considered as mediators

between immigrant status and onset of cigarette smoking

during an early age [39]. We used the two-step method

because the variable age of smoking onset could not be

modeled using linear regression due to censoring.

All statistical analyses were completed using the com-

mercial software SAS version 9.2 on computer.

Results

Characteristics of the Study Sample

Among the 6,468 participants included in the analysis,

2,137 were in grade 7, 2,042 in grade 8 and 2,289 in grade

9; 51% were boys and 49% were girls. The average age

was 13.3 (SD = 1.1) for boys and girls. Among all the

participants, 69.5% of girls rated their school performance

to be on average or higher, compared to 66.9% of boys.

21.8% of the participants were immigrant students

(Table 1).

Prevalence of and Factors Associated with Smoking

Table 2 indicates that the percentage rates of lifetime

smoking and past 30-day smoking were 10.2 (95% CI: 9.5,

10.9) and 4.3 (95% CI: 3.8, 4.8) for the study sample. The

variables age, gender and self-rated school performance

were all associated with lifetime smoking and 30-day

smoking (no overlap in the 95% CI of the smoking rates

between the comparisons groups) with only one exception

(i.e. immigrant status and 30-day smoking). For example,

the percentage rate of lifetime smoking was significantly

higher among boys than among girls (11.5, 95% CI: 10.4,

12.6 vs. 8.8, 95% CI: 7.8, 9.8; P \ 0.05 from Chi-square

test). Apart from demographic and school performance,

parental smoking, parental monitoring, children depression

were all associated with lifetime smoking and 30-day

smoking.

Hazards of Smoking Onsets

The reported age of smoking onset from the survey fit the

survival model successfully, and the hazards of smoking

onset for Chinese adolescents in Hong Kong followed a

Weibull distribution. A general pattern of smoking onset

appeared for both boys and girls: the hazards to initiate

smoking were below 1% before age 10, increased rapidly

thereafter along with age, and peaked at around 12 years of

age with the hazards level of approximately 3%. However,

compared to girls, the hazards were greater for boys before

11 years of age; there was a decline trends in the hazards of

smoking onset for girls after age 12 and no such declining

trend was observed for boys (Fig. 1). Log-rank test

J Community Health (2012) 37:144–152 147

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indicated that this gender difference in the age patterns of

the hazards of smoking onset was significant (P \ 0.05).

As shown in Fig. 2, the hazards were consistently

greater for participants who were immigrant students

compared to those who were non-immigrant students.

While the hazards for non-immigrant students declined

after age 12, the same hazards continued to increase for

immigrant students. Log-rank test indicated that this dif-

ference was extremely significant (P \ 0.01).

Factors Mediated the Association Between Immigrant

Status and Age of Smoking Onset

Results from logistic regression indicated that after con-

trolling for gender and age, being immigrant students (non-

immigrant students as reference) was significantly

associated with reductions in parental monitoring

(OR = 0.88, 95% CI: 0.78, 0.99), increased paternal

smoking (OR = 1.51, 95% CI: 1.33, 1.71), and reduced

maternal smoking (OR = 0.74, 95% CI: 0.56, 0.98). The

association between immigrant status and children

depression was not significant (OR = 1.11, 95% CI: 0.99,

1.26). Results in Table 3 indicate that paternal smoking

(OR = 1.71, 95% CI = 1.43, 2.04), maternal smoking

(OR = 1.98, 95% CI = 1.54, 2.55), parental monitoring

(OR = 0.52, 95% CI = 0.42, 0.64) and children depres-

sion (OR = 2.14, 95% CI = 1.79, 2.55) were all highly

significantly associated with the age of smoking onset after

gender, school performance and immigrant status were

included as covariates.

Discussion

In this study, we documented the age pattern of smoking

initiation among Chinese adolescents in Hong Kong with a

random sample of 6,468 students; assessed factors associ-

ated with prevalence of smoking and hazards of early

smoking onset with particularly emphasis on the influences

of immigrant status and other factors that may have med-

iated the association between immigrant status and smok-

ing onset. In addition to adding new data on adolescent

smoking in Hong Kong, findings of this study extend our

previous research on smoking among Chinese youth across

diverse cultural backgrounds [5, 6].

Immigrant Status and Hazards of Early Smoking Onset

One important finding of this study is that being an

immigrant student was associated with increased risk of

early smoking onset, compared to non-immigrant students

in Hong Kong. Furthermore, this association was partially

mediated by reductions in parental monitoring and

increases in parental smoking. It is consistent with our

hypothesis that immigrant children who have smoking

parents, and/or whose parents with less likely to monitor

them are more likely to start smoking in an early age.

Although depression was significantly associated with

early smoking onset, the levels of depressive symptoms

were not significantly associated with immigrant status.

This could be explained by the fact that more than 90% of

the immigrant students have already stayed in Hong Kong

for more than a year. Furthermore, the majority of OWP

holders came from the Guangdong province neighboring

with Hong Kong with the same dialect and short travel

distances [24]. Immigrant children from these families may

not experience much difficulty in adapting the local envi-

ronment and school conditions.

Table 1 Demographic characteristics of the study sample

(N = 6,468)a, b

Boys Girls Total

Total 3,299 (51.0%) 3,169 (49.0%) 6,468

Age in years

B12 years 941 (28.5%) 885 (27.9%) 1,826 (28.2%)

13 years 909 (27.6%) 915 (28.9%) 1,824 (28.2%)

14 years 1,004 (30.4%) 1,077 (34.0%) 2,081 (32.2%)

C15 years 445 (13.5%) 292 (9.2%) 737 (11.4%)

Mean (SD) 13.3 (1.2) 13.3 (1.1) 13.3 (1.1)

Grade

7th 1,158 (35.1%) 979 (30.9%) 2,137 (33.0%)

8th 1,073 (32.5%) 969 (30.6%) 2,042 (31.6%)

9th 1,068 (32.4%) 1,221 (38.5%) 2,289 (35.4%)

Immigrant status

Non-immigrant students 2,530 (77.1%) 2,509 (79.4%) 5,039 (78.2%)

Immigrant students 753 (22.9%) 650 (20.6%) 1,403 (21.8%)

Missing 16 10 26

Self-rated school performance

Average or higher 2,189 (66.9%) 2,190 (69.5%) 4,379 (68.2%)

Below average 1,085 (33.1%) 959 (30.5%) 2,044 (31.8%)

Missing 25 20 45

Maternal education

Primary or below 419 (12.7%) 409 (12.9%) 828 (12.8%)

Middle school 1,542 (46.8%) 1,791 (56.6%) 3,333 (51.6%)

College or above 336 (10.2%) 337 (10.7%) 673 (10.4%)

Don’t know 997 (30.3%) 626 (19.8%) 1,623 (25.1%)

Missing 5 6 11

Paternal education

Primary or below 333 (10.1%) 352 (11.1%) 685 (10.6%)

Middle school 1,506 (45.7%) 1,604 (50.8%) 3,110 (48.2%)

College or above 419 (12.7%) 438 (13.9%) 857 (13.3%)

Don’t know 1,035 (31.4%) 766 (24.2%) 1,801 (27.9%)

Missing 6 9 15

a Male and female may not add up to total N due to missing datab All percentages are column percentages except for total gender

148 J Community Health (2012) 37:144–152

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Table 2 Prevalence rates and influential factors associated with cigarette smoking among Chinese youth in Hong Kong

Lifetime smoking 30-day smoking

Frequency Percentage (95% CI) Frequency Percentage (95% CI)

Total 655 10.2 (9.5, 10.9) 279 4.3 (3.8, 4.8)

Gender

Girls 277 8.8 (7.8, 9.8)** 117 3.7 (3.0, 4.4)*

Boys 378 11.5 (10.4, 12.6) 162 4.9 (4.2, 5.6)

Immigrant status

Non-immigrant students 448 8.9 (8.1, 9.7)** 207 4.1 (3.6, 4.6)

Immigrant students 204 14.7 (12.8, 16.6) 70 5.0 (3.9, 6.1)

Missing 3 2

Self-rated school performance

Average or higher 327 7.5 (6.7, 8.3)** 129 2.9 (2.4, 3.4)**

Below average 321 15.8 (14.2, 17.4) 146 7.2 (6.1, 8.3)

Missing 7 4

Maternal smoking

Yes 97 25.0 (20.7, 29.3)** 44 11.3 (8.2, 14.4)**

No or don’t know 555 9.2 (8.5, 9.9) 233 3.9 (3.4, 4.4)

Missing 3 2

Paternal smoking

Yes 325 15.7 (14.1, 17.3)** 140 6.7 (5.6, 7.8)**

No or don’t know 326 7.5 (6.7, 8.3) 138 3.2 (2.7, 3.7)

Missing 4 1

Depressiona

Low 243 6.1 (5.4, 6.8)** 87 2.2 (1.7, 2.7)**

High 405 16.9 (15.4, 18.4) 187 7.7 (6.6, 8.8)

Missing 7 5

Parental monitoringa

Low 513 14.2 (13.1, 15.3)** 223 6.1 (5.3, 6.9)**

High 139 5.1 (4.3, 5.9) 54 2.0 (1.5, 2.5)

Missing 3 2

* P \ 0.05; ** P \ 0.01a Depression scores below median score are defined as low level depression. Similarly, parental monitoring scores below median score are

defined as low level of parental monitoring

Fig. 1 Differences in hazards of smoking onsets between boys and

girls in Hong Kong

Fig. 2 Difference in hazards of smoking onset between immigrant

and non-immigrant students in Hong Kong

J Community Health (2012) 37:144–152 149

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Age and Gender Differences in Hazards of Smoking

Onset

Despite the relatively lower levels of hazards of smoking

onset, the age pattern of the hazards of smoking onset among

Chinese youth in Hong Kong was similar to those observed

among Chinese youth in Mainland China and in the United

States. The hazards are rather low before 10 years of age and

they then increase sharply thereafter. Compared to other

places, gender differences in hazards of smoking onset by

age were relatively smaller for adolescents in Hong Kong.

The hazard of smoking initiation for boys in Hong Kong was

rather low before 10 years old, which was similar to that

observed from Chinese boys in other places. However, the

hazards for Chinese girls in Hong Kong were greater than

Chinese girls in Mainland China [5]. Furthermore, the level

of hazards of smoking initiation for youth in Hong Kong

were rather low (\1.5%) prior to 10 years of age, peaked at

age 12 (approximately 3%), compared with the hazards for

youth in Mainland China (\3% before 9 years of age, with

peak levels from 9 to 11.5% for boys and about 2.5–3.5% for

girls at age 13–14) [5].

Compared with Chinese girls in other places [5, 6], the

relatively higher risk of smoking onset and prevalence rate

among girls in Hong Kong could be due to the recent

trends in emphasizing the link between tobacco con-

sumption and images of western-styled modern women as

portrayed by tobacco industry’s marketing strategies [40,

41]. Teenage girls in Hong Kong are extensively exposed

to mass media from diverse sources regarding the ‘ideal

weight’ and body shape. Therefore, using tobacco may

become one option for their weight control [8, 40, 42, 43].

Furthermore, increased risk for teenage girls to start

smoking may also be a response to the highly competitive

and stressful life experiences in Hong Kong [13, 40].

Further studies are needed to examine the relatively

smaller gender differences in smoking onset among youth

in Hong Kong. The gender differences in smoking among

Hong Kong youth anticipates an emerging trend for more

girls to smoke in other Chinese populations with similar

patterns of socioeconomic development in Asia. It may be

particularly true for the rise in cigarette smoking among

female adolescents in the Mainland along with the rapid

socioeconomic changes [41].

Limitations

There are limitations to this study. First, data used for this

analysis are cross-sectional in nature. The identified asso-

ciations in this analysis must be verified using longitudinal

design in order to draw any causal conclusion. Second,

smoking behavior was based on self-report, and misrep-

orting could not be ruled out without biomarker-verified

data. Third, a few commonly examined factors (such as

peer influences and pro-tobacco media) are not included in

this survey. Given the limitations, this study is the first

attempt to examine hazards of smoking onset among Chi-

nese youth in Hong Kong. The findings can advance our

understanding of the age pattern of smoking onset, and

provide evidence for youth smoking prevention interven-

tion programs.

Implications for School Health

Findings of this analysis provide new evidence for school-

based tobacco use prevention to promote health behavior

among students in Hong Kong. First, the age pattern of the

hazards of smoking onset indicates that the ideal age for

school-based adolescent smoking prevention should not be

later than 12 years of age or grade 6 before the hazards of

smoking onset reach their peak. Second, to reduce tobacco

use among students in Hong Kong, priority should be given

to immigrant children. Third, when schools plan and

implement smoking prevention programs, parental factors

must also be considered. Examples include parental mon-

itoring of child smoking and tobacco cessation for smoking

parents and provision of tobacco cessation to the smoking

parents. This is particularly true for parents of immigrant

children because of the high smoking rates of these parents.

In addition to school-based prevention, measures targeting

at reducing prevalence rate of adult smoking, particularly

immigrants, should be emphasized in order to effectively

prevent early smoking onset among children of immigrant

families. Fourth, special attention should be paid to the

relatively greater hazards of smoking onset among Chinese

girls in Hong Kong. The findings also give insight to other

Chinese adolescent populations with similar patterns of

socioeconomic development in the neighboring societies.

Acknowledgments This analysis is one of the research outputs

from the project of the Action Health, which is a part of the project

Table 3 Factors associated with age of smoking onset: odds ratio

(95% CI) from proportional hazards regression analysisa

Variables Odds ratio (OR) 95% CI

Male gender 1.28** 1.08, 1.53

Poor school performance 1.73** 1.46, 2.06

Depression 2.14** 1.79, 2.55

Parental monitoring 0.52** 0.42, 0.64

Paternal smoking 1.71** 1.43, 2.04

Maternal smoking 1.98** 1.54, 2.55

Immigrant status 1.12 0.92, 1.35

** P \ 0.001a Likelihood ratio = 313.9

150 J Community Health (2012) 37:144–152

123

Chinese Student Health Survey. Data collection for this study was

supported by the Centraline Charity Fund Limited.

Conflict of interest All authors have no conflict of interests asso-

ciated with the funding agency.

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