The changing prevalence of health-risk
behaviors among high school students inOkinawa, Japan, 2002-2008
Minoru Takakura, Ph.D.
Graduate School of Health Sciences
University of the Ryukyus
JC-GSHR School Health Seminar at Okinawa
7th March, 2013

Background The burden of mortality and morbidity from non-communicable diseases has increased worldwide,
whereas the burden from infectious diseases has declined.

 In 2010, 56% of all deaths in Japan were due to cancer(30%), cardiovascular diseases (16%), andcerebrovascular diseases (10%), that is, common noncommunicable diseases related to unhealthy lifestyle.

 Unhealthy lifestyle includes tobacco, alcohol, and otherdrug use, risky driving, self-harm, unsafe sexualbehaviors, unhealthy diet, physical inactivity, and so on.

2Comparison between life expectancy at birth andat 75 in Japanese males
National average at birth
Okinawa
12.22 at 75
78.64 at birth

National average
at 75

Ministry of Health, Labour and Welfare : Complete life table. 2005

The leading causes of death among Japaneseyouth ages 10 to 14
Unintentional
injuries
22%

Others34%

Malignantneoplasm
21%

Congenitalabnormality
4%Cardiovasculardisease8%

Suicide11%
Ministry of Health, Labour and Welfare : Vital statistics. 2010

The leading causes of death among Japaneseyouth ages 15 to 19
Others22%
Congenitalabnormality
2%

Suicide32%

Cardiovasculardisease4%
Malignantneoplasm
11%

Unintentional
injuries
30%
Ministry of Health, Labour and Welfare : Vital statistics. 2010

Background

The leading causes of mortality and morbidity among youthand adults in Japan are associated with health-risk behaviors.

US. CDC has classified priority health-risk behaviors among
youth into six categories:
1. Behaviors that contribute to unintentional injuries andviolence
2. Tobacco use
3. Alcohol and other drug use
4. Sexual behaviors that contribute to unintentional
pregnancy and sexual transmitted disease
5. Unhealthy dietary behaviors
6. Physical inactivity
6

Background These risk behaviors are often established during youth,

extend into adulthood, and are interrelated andpreventable.
 In order to plan, implement, and evaluate effective
prevention policies and programs, monitoring theprevalence and trends in health-risk behaviors among
youth is important.
 However, there was no continuing survey regarding
comprehensive health-risk behaviors among Japaneseyouth.
 Accordingly, we investigated the recent trend in many
health-risk behaviors among high school students in
Okinawa, Japan, during 2002-2008.
7

Methods
 We conducted 3 cross-sectional surveys in 2002, 2005,

and 2008, using a self-administered anonymousquestionnaire to obtain a wide range of health,sociodemographic and psychosocial information fromstudents.

 The study sample of each survey consisted of all students

in a class in each of grades 10-12 (aged 15-18 years)
enrolled in public high schools selected across Okinawa,with a probability proportional to the number of schools.

8Measures
 Health-risk behaviors (questions were adapted from theYRBS)

7 questions for behaviors that contribute to injuries
 6 questions for tobacco smoking
 6 questions for alcohol and other drug use
 5 questions for sexual behaviors
 6 questions for dietary behaviors
 To determine whether an actual change in the prevalenceof health-risk behaviors has occurred over time, we usedlogistic regression analyses that assess the trends andcontrol for grade, school type, and region.

9Table 1. Distributions of students by demographic characterisitics.
20022005
2008
n%
n%
n%
GenderMale
1219 48.0
1057 42.8
1424 50.0
Female1321 52.01415 57.2
1426 50.0p<0.001Grade

1st2nd3rd

903
887
750

35.6
34.9
29.5

874
819
779

35.4
33.1
31.5

993
974
883

34.8
34.2
31.00.535

School type

General HS
Vocational HS

1729
811

68.1
31.9

1709
763

69.1
30.9

1896
954

66.5
33.5

0.122

RegionOkinawa Island
Remote islands

2142
398

84.3
15.7

2055
417

83.1
16.9

2446
404

85.8
14.2

0.025

Total

102540 100.02472 100.02850 100.0

Results
 Overall, improvements in some health-risk behaviors

were found between 2002 and 2008.

Behaviors contribute to injuries (safety driving) Seat belt use, motorcycle helmet use (girls), and riding with adrinking driver

Tobacco use Alcohol use Sexual behaviors Being sexually active, condom use

Unhealthy diet (girls)

 Conversely, having been offered, sold, and given an illegal

drug and carrying a weapon among boys were gettingworse.

11

The prevalence of behaviors contribute toinjuries
(%)

8070

♂

60

♀

♂

♀

50
45.6

42.3

40
35.6
26.7

30

13.2

10

21.8

n.s.

20

12.3

32.0

23.1

11.9
8.8

9.4

0

'02 '05 '08'02 '05 '08

Rarely or never wore helmet
12'02 '05 '08'02 '05 '08

Rarely or never wore seatbelt

The prevalence of behaviors contribute toinjuries
(%)

8070

♂

60

♀

♂

♀

50
40
30
20
10

11.2

14.9

10.8

n.s.

9.7
4.2

4.8

0

'02 '05 '08'02 '05 '08

Ride with drinking driver (month)
13

3.7

6.3

6.3

'02 '05 '085.5
3.8

3.6

'02 '05 '08

Carrying a weapon (year)

The prevalence of current cigarette use (month)
Okinawa♂
Okinawa♀
Japan♂
Japan♀

5040%
30

30.7

29.9
24.9

20
15.9
12.6

17.4

13.1

11.5
9.7

10.5

108.2
5.4

6.1
4.5

0
1996

142000

2002

2004

2005

2008

The prevalence of current alcohol use (month)
50

49.7

40

40.8

Okinawa♂
Okinawa♀
Japan♂
Japan♀

48.7
42.1

41.8
39.7
36.2
34.1

%
30

33.8
32.3
22.5
20.6

20

20.5
20.5

100
1996

152000

2002

2004

2005

2008

The prevalence of other alcohol and drug use
(%)

3025

♂
20
1510

♀

♂

♀

19.7
16.4
14.8
10.2

116.7

5

3.3
3.0
1.3

0

'02 '05 '08'02 '05 '08

Binge drinking (month)16

2.8'02 '05 '08

1.9

2.0

'02 '05 '08

Offered, Sold, or Given an Illegal
Drug (year)

The prevalence of sexual behaviors
(%)

90
82.5

80

75.2

75.4

70

73.5
63.0

60

58.4

50
40
30
20
10

27.8
18.9

17.0

24.0

21.2

15.5

♂

♀

♂

♀

'02 '05 '08'02 '05 '08'02 '05 '08'02 '05 '08

0Ever had sexual intercourse
17Condom use

The prevalence of unhealthy diet
(%)

1098

♂

7

♀

♂

♀

6

5.9
5.1

5

3.9

4
3.1

3

2.4

2
10

1.9

n.s.

1.0
0.5

0.6

'02 '05 '08

18

n.s.

0.6

'02 '05 '08

Took diet pills, powders, orliquids to lose weight (month)

0.7

0.8

'02 '05 '08'02 '05 '08

Vomited or took laxatives to lose
weight (month)The reasons behind selected health-risk
behaviors change 1
 Behaviors contribute to injuries (safety driving)19

Strengthening crackdown and enlightenment of therevised “Road Traffic Law”
 In 2002, raise penalty for risky driving
 In 2004, revision of penalty for cell-phone use whiledriving
 In 2007, raise penalty for drinking driving and growing
social norm of prevention drinking driving
 In 2008, obligation of seat belt use in the backseat

The reasons behind selected health-risk
behaviors change 2 Tobacco use

Development and implementation of National Health
Promotion Policy “Healthy Japan 21” and “HealthyOkinawa 2010”
 In 2003, enforcement of “passive smoking prevention”
provided for in Article 25 of the “Health Promotion Act”
 Smoking bans on school property or public spaces
 In 2003, 2006, 2010, increase in retail price of cigarettes
 A decrease in smoking prevalence of their father andolder brothers, and an increase in the proportion of those
who had no friend might contribute to decreasing trend inadolescent smoking (Osaki et al., 2008).
20

The reasons behind selected health-risk
behaviors change 3
 Alcohol use


Revision of the “Act to Prohibit Minors from Drinking” and the“Liquor Tax Law”
In 2000, strengthening penalty for selling alcohol beverages tominors and the revocation of a liquor license from liquor retailersbe against the Act to Prohibit Minors from Drinking

In 2001, reinforcement of the age confirmation by the liquor
distributors

In 2007, raise penalty for drinking driving and growing therelevant social norm against drinking driving
 Similar to smoking, a decrease in drinking prevalence of theirfather and older brothers, and an increase in the proportion of
those who had no friend might contribute to decreasing trendin adolescent drinking (Osaki et al., 2009).
21

The reasons behind selected health-riskbehaviors change 4

Sexual experienceCondom use

School-based sex education and enlightenment activities forHIV/AIDS prevention by the local authorities might contribute to
the decrease in the prevalence of having had sexual intercourse.
In 2002, addressing AIDS/STD as a type of infectious disease andthe effectiveness of condom use to the prevention were added in
the contents of “Health” in the course of study of junior highschool. Then, the learning effect on these contents might beestablished in high school students.

Unhealthy diet

22After 2002, since health hazards of “health foods” such as Chinesemade diet aids were often reported, many girls might hesitate touse those diet aids.

Conclusion
 This study shows that overall some health-risk

behaviors among high school students in Okinawa
improved between 2002 and 2008.
 The improvement of health-risk behaviors may be
due to revisions of law and changes in social
environment, as well as school-based healtheducation.
 It seems that the population approach, which aims tocontrol the determinants of health toward lower
levels of risk exposure in the entire population,
would be effective and important to improve healthin youth population.
23

Thank you for your attention.

24

ReferencesCenters for Disease Control and Prevention. Youth Risk Behavior Surveillance -UnitedStates, 2009. MMWR 2010;59(No. SS-5).



Centers for Disease Control and Prevention. 2011 Youth Risk Behavior Survey.
Available at: www.cdc.gov/yrbs.

Centers for Disease Control and Prevention. Interpretation of YRBS trend data. June
2010. Available at:
http://www.cdc.gov/healthyyouth/yrbs/pdf/YRBS_trend_interpretation.pdf.

Osaki Y, Tanihata T, Ohida T, et al. Decrease in the prevalence of smoking among
Japanese adolescents and its possible causes: periodic nationwide cross-sectional
surveys. Environ Health Prev Med 2008;13:219-26.

Osaki Y, Tanihata T, Ohida T, et al. Decrease in the prevalence of adolescent alcohol
use and its possible causes in Japan: periodical nationwide cross-sectional surveys.
Alcohol Clin Exp Res 2009;33:247-54.

Takakura M. The changing prevalence of health-risk behaviors among high school
students in Okinawa, Japan, 2002-2008. Jpn J Sch Health 2012;54(2):170177. (in Japanese with English abstract)25