Unhealthy lifestyle, poor mental health, and its correlation among adolescents: a nationwide cross-sectional survey.

OBJECTIVES: The objective was to study the relationship between mental health and lifestyles of adolescents using samples representative of Japanese adolescents nationwide. METHOD: The survey was conducted between December 2004 and January 2005 among students enrolled in randomly selected junior and senior high schools. Self-administered questionnaires addressed lifestyles, sleeping habits, and mental health status. Of 103 650 questionnaires collected, 85 158 were analyzed. RESULTS: Population characteristics associated with poor mental health were being female, being a senior high school student, skipping breakfast, not participating in extracurricular activities, not consulting parents about personal matters, parental smoking, students' smoking or alcohol use, poor subjective sleep assessment, and short or long sleeping duration. CONCLUSION: Smoking and anxiety disorders are associated with an elevation in acculturative stress in adolescents. Prepossessing adolescents are in subclinical depression. Results suggest that lifestyles approaches in preventions that target students can be effective in reaching high-risk populations.

Incidence of sexually transmitted diseases in Hokkaido, Japan, 1998 to 2001.

The objective of this study was to provide precise data on the incidence of sexually transmitted diseases (STDs) in Hokkaido. The goal of this prospective surveillance, study was to clarify the STD incidence between 1998 and 2001 in Hokkaido, Japan. The incidence of gonococcal infection in men was found to be 127-199 per 100000 people per year, which was three or four times higher than that for women. Female genital chlamydial infection had an incidence of 300-400 with a female to male ratio of two or three to one. Younger adults had higher incidences of gonococcal and chlamydial infections than older people. In conclusion, the current study of STDs revealed high incidences of gonococcal and chlamydial infections in the Hokkaido area, and there was no decreasing trend in STD incidence during these 4 years.

The association between use of mobile phones after lights out and sleep disturbances among Japanese adolescents: a nationwide cross-sectional survey.

STUDY OBJECTIVE: The objective of this study was to examine the association between the use of mobile phones after lights out and sleep disturbances among Japanese adolescents. DESIGN AND SETTING: This study was designed as a cross-sectional survey. The targets were students attending junior and senior high schools throughout Japan. Sample schools were selected by cluster sampling. Self-reported anonymous questionnaires were sent to schools for all students to fill out. PARTICIPANTS: A total of 95,680 adolescents responded. The overall response rate was 62.9%, and 94,777 questionnaires were subjected to analysis. INTERVENTION: N/A. MEASUREMENTS AND RESULTS: Daily mobile phone use, even if only for a brief moment every day, was reported by 84.4%. Moreover, as for use of mobile phones after lights out, 8.3% reported using their mobile phone for calling every day and 17.6% reported using it for sending text messages every day. Multiple logistic regression analysis showed that mobile phone use for calling and for sending text messages after lights out was associated with sleep disturbances (short sleep duration, subjective poor sleep quality, excessive daytime sleepiness, and insomnia symptoms) independent of covariates and independent of each other. CONCLUSION: This study showed that the use of mobile phones for calling and for sending text messages after lights out is associated with sleep disturbances among Japanese adolescents. However, there were some limitations, such as small effect sizes, in this study. More studies that examine the details of this association are necessary to establish strategies for sleep hygiene in the future.

Nightmare and sleep paralysis among Japanese adolescents: a nationwide representative survey.

OBJECTIVE: The objective of this study was to clarify the prevalence of nightmares and sleep paralysis and associated factors among Japanese adolescents. METHODS: This study was designed as a cross-sectional sampling survey. The targets were junior and senior high schools throughout Japan. Self-reported anonymous questionnaires were sent to schools for all students to complete. RESULTS: A total of 90,081 questionnaires were analyzed. The overall response rate was 62.6%, and the prevalence of nightmares and sleep paralysis was 35.2% and 8.3%, respectively. Multiple logistic analyses revealed that female sex, drinking alcohol, poor mental health, difficulty initiating sleep, low subjective sleep assessment, presence of excessive daytime sleepiness, and presence of sleep paralysis had higher odds ratios than others for nightmares. Male sex, poor mental health, drinking alcohol, taking a long daytime nap, early or late bedtime, difficulty initiating sleep, low subjective sleep assessment, presence of excessive daytime sleepiness, and presence of nightmares had higher odds ratios than other factors for sleep paralysis. CONCLUSIONS: This study has revealed the prevalence of nightmares and sleep paralysis among Japanese adolescents. Furthermore, the results of this study suggest that it is important to maintain regular sleep habits for preventing these symptoms. We propose that health education about regular sleep habits should be promoted among Japanese adolescents.

Clarification of the factor structure of the 12-item General Health Questionnaire among Japanese adolescents and associated sleep status.

If the factors affecting the mental health status of adolescents and their association with sleep status could be clarified, this information would be helpful for formulating lifestyle and healthcare guidance for the promotion of healthy growth and the prevention of mental problems in these individuals. The purpose of this study was to clarify (1) the factor structure of the 12-item General Health Questionnaire (GHQ-12), and (2) the associations between the factors extracted from this questionnaire and lifestyle, in particular sleep status, by using a representative sample population of Japanese adolescents. One hundred three thousand sixty hundred fifty self-administered questionnaires were collected from students enrolled in junior high and high schools in Japan. Of these questionnaires, 99,668 were analyzed. Sleep duration, subjective sleep assessment, bedtime, and insomnia symptoms of these students over the past month were studied to investigate sleep status. The factor analyses yielded two factors: depression/anxiety and loss of positive emotion. Sleep duration of less than 7h was found to be associated with both depression/anxiety and loss of positive emotion, whereas sleep duration of 8h or more was associated only with loss of positive emotion. Subjective sleep assessment and insomnia symptoms were associated with both depression/anxiety and loss of positive emotion. It was demonstrated that two underlying factors of mental health status were associated with differences in sleep status. In order to improve the mental health status of adolescents, it is important to provide guidance about sleep and lifestyle habits according to the mental health status of the individual.

Decrease in the prevalence of adolescent alcohol use and its possible causes in Japan: periodical nationwide cross-sectional surveys.

BACKGROUND: Trends in alcohol drinking prevalence were assessed among Japanese adolescents, and possible reasons for a decrease in drinking prevalence observed in 2004. METHODS: Cross-sectional nationwide surveys were conducted periodically. High schools were randomly sampled from throughout Japan in 1996, 2000, and 2004. All enrolled students in sampled schools were subjects of the surveys. Self-reporting anonymous questionnaires were collected from 115,814 students in 1996, 106,297 in 2000, and 102,451 in 2004. Questions about drinking prevalence of students and family members, proportion of students who have no friends, and sources of alcohol were included. Students who drunk at least one day of the 30 days preceding the survey were defined as the current drinkers. RESULTS: The drinking prevalence in 2004 was decreased in comparison to that in 1996 and 2000 in both sexes and in all school grades. The current drinking rate (monthly drinker) among junior high school boys was 29.4% in 1996, 29.0% in 2000, and 20.5% in 2004, while that among senior high school boys was 49.7%, 48.7%, and 36.2%, respectively. The respective prevalence among junior and senior girls was 24.0%, 25.5%, and 20.0% and 40.8%, 42.1%, and 34.1%. The prevalent sources of alcohol beverages were searching in home, stores (convenience store, supermarket, or gas-stand), liquor shops, and bars. An analysis of the reasons for this decrease identified a decrease in drinking prevalence in students' families, especially by fathers and older brothers, and an increase in the proportion of students who had no friends. CONCLUSIONS: A decrease in drinking prevalence of male family members and a limitation of sources of alcoholic beverages may contribute to the decrease in adolescent drinking prevalence.

Decrease in the prevalence of smoking among Japanese adolescents and its possible causes: periodic nationwide cross-sectional surveys.

OBJECTIVES: To assess trends in smoking prevalence among Japanese adolescents and to analyze possible causal factors for the decrease in smoking prevalence observed in a 2004 survey. METHODS: Nationwide cross-sectional surveys were conducted in 1996, 2000 and 2004. Survey schools, both junior and senior high schools, considered to be representative of the whole of Japan were sampled randomly. Enrolled students were asked to complete a self-reporting anonymous questionnaire on smoking behavior. The questionnaires were collected from 115,814 students in 1996, 106,297 in 2000, and 102,451 in 2004. School principals were asked about the policy of their respective school on smoking restrictions. RESULTS: Cigarette smoking prevalence (lifetime, current, and daily smoking) in 2004, based on the completed questionnaires, had decreased relative to previous years in both sexes and in all school grades. The most important trends were: a decrease in smoking prevalence among the fathers and older brothers of the students; an increase in the proportion of students who did not have friends; a decrease in the proportion of current smokers who usually bought cigarettes in stores decreased in 2004, in particular for the oldest boys. An association was found between a lower smoking rate at a school and a smoke-free school policy. CONCLUSIONS: Japan has experienced a decrease in the prevalence of smoking among adolescents. A decrease in smoking prevalence among the fathers and older brothers, limitations to minors' access to tobacco, an increase in the proportion of students without friends, and a school policy restricting smoking may have contributed to this decreasing trend.

Association between mental health status and sleep status among adolescents in Japan: a nationwide cross-sectional survey.

OBJECTIVE: Previous epidemiological studies on relationships between mental health status and sleep status of adolescents have not been sufficiently representative. In the present study, using samples representative of Japanese adolescents nationwide, associations between mental health status and various sleep statuses were examined. METHOD: The survey was conducted in December 2004 and January 2005 among students enrolled in randomly selected junior and senior high schools throughout Japan, using self-administered questionnaires that addressed lifestyle, sleep status, mental health status, and personal data. Of 103,650 questionnaires collected, 99,668 were analyzed. Sleep status was assessed according to sleep duration, subjective sleep assessment, bedtime, and insomnia symptoms. The Japanese version of the 12-item General Health Questionnaire was employed for assessment of mental health status. RESULTS: Mental health status of subjects whose sleep duration was less than 7 hours, and those who slept 9 hours or more, was poorer than that of subjects who slept for 7 hours or more but less than 9 hours. A U-shaped association was observed between mental health status and sleep duration. Furthermore, a linear association was observed between subjective sleep assessment and mental health status; the worse the subjective sleep assessment, the poorer the mental health status. Mental health status was also inversely proportional to the frequency of insomnia symptoms. CONCLUSION: The fact that sleep duration and subjective sleep assessment showed different patterns of association with mental health status indicates that these 2 sleep parameters have independent significance. Considering these associations, it is important to promote mental health care and sleep hygiene education for adolescents.

[Decreases in Japanese adolescent drinking in 1996, 2000 and 2004 national surveys of Japanese junior and senior high school students].

We conducted three national surveys to clarify the drinking status of Japanese junior and senior high school students in 1996, 2000 and 2004. The total numbers of subjects in each survey were about 50 thousands junior high school students and 70 thousands senior high school students. The present study compares drinking status and alcohol related problems of the subjects of the three surveys. The results were as follows. First, drinking experiences of the subjects decreased over the three surveys. Those of junior high school students dropped from 60% to 40%, and those of senior high school students from 75% to 60%. Second, drinking behavior of the subjects has changed, e.g., the amount of drinking on each occasion has decreased, failures due to drunkenness have also decreased, compliance with the Law Prohibiting Minors Drinking has increased, their buying alcoholic drinks has decreased and experiences of being offered alcohol by parents have decreased. Third, male problem drinkers among the subjects decreased slightly but female problem drinkers did not decrease. We discussed the reasons why Japanese adolescent drinking has decreased. Over the past 10 years, Japanese society started to prohibit adolescent drinking, by revising the Law Prohibiting Minors Drinking, penalties for driving while intoxicated became more severe and Japanese alcohol consumption started to decrease.

Insomnia among Japanese adolescents: a nationwide representative survey.

STUDY OBJECTIVES: Although a number of previous studies have examined the prevalence of insomnia among adolescents, there have been very few nationwide studies. The objectives of this nationwide study were to clarify the prevalence of insomnia, its symptoms, and associated factors among Japanese adolescents. DESIGN AND SETTING: This study was designed as a cross-sectional sampling survey. The targets were junior and senior high schools throughout Japan. Sample schools were selected by cluster sampling. Self-reported anonymous questionnaires were sent to schools for all students to fill out. PARTICIPANTS: A total of 103,650 adolescents responded, and 102,451 questionnaires were subjected to analysis. INTERVENTION: N/A. MEASUREMENTS AND RESULTS: The prevalence of difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening was 14.8%, 11.3%, and 5.5%, respectively. Insomnia was defined as the presence of one or more of these three symptoms. The prevalence of insomnia was 23.5%. Multivariate analyses revealed that, among junior high school students, male sex, poor mental health, skipping breakfast, drinking alcohol, smoking, not participating in extracurricular activities, and late bedtime had significantly higher odds ratios for insomnia. Among senior high school students, the same characteristics were associated with a significantly higher odds ratio for insomnia, as was the additional factor of having no intent to study at university. CONCLUSION: Insomnia in Japanese adolescents is common and associated with multiple factors. The results of this study suggest the need for comprehensive program to prevent insomnia in Japanese adolescents.

An epidemiologic study of self-reported sleep problems among Japanese adolescents.

STUDY OBJECTIVE: To examine the prevalence and correlates of sleep problems in Japanese adolescents. DESIGN AND SETTING: The survey was designed as a cross-sectional sampling. The targets of the survey were junior and senior high schools throughout Japan. Sample schools were selected by stratified cluster sampling. Self-reported anonymous questionnaires were sent to sample schools for all students to fill out. PARTICIPANTS: A total of 107,907 adolescents responded, and 106,297 questionnaires were subjected to analysis. MEASUREMENTS AND RESULTS: The overall prevalences of sleep problems in the month preceding the questionnaire were difficulty initiating sleep (boys: 15.3%, girls: 16.0%); nocturnal sleep duration less than 6 hours (boys: 28.7%, girls: 32.6%); excessive daytime sleepiness (boys: 33.3%, girls: 39.2%), and subjectively insufficient sleep (boys: 38.1%, girls: 39.0%). Multiple logistic regression analysis showed that female sex, being a senior high-school student, and having an unhealthy lifestyle (psychological stress, smoking, and drinking alcohol) were risk factors for sleep problems. CONCLUSION: Self-reported sleep problems in Japanese adolescents were common and were associated with multiple factors. There is a need for health education directed at solving sleep problems in Japanese adolescents.

Incidence of sexually transmitted diseases in Hokkaido, Japan, 1998 to 2001.

The objective of this study was to provide precise data on the incidence of sexually transmitted diseases (STDs) in Hokkaido. The goal of this prospective surveillance, study was to clarify the STD incidence between 1998 and 2001 in Hokkaido, Japan. The incidence of gonococcal infection in men was found to be 127-199 per 100 000 people per year, which was three or four times higher than that for women. Female genital chlamydial infection had an incidence of 300-400 with a female to male ratio of two or three to one. Younger adults had higher incidences of gonococcal and chlamydial infections than older people. In conclusion, the current study of STDs revealed high incidences of gonococcal and chlamydial infections in the Hokkaido area, and there was no decreasing trend in STD incidence during these 4 years.

Risk of adverse reproductive outcomes associated with proximity to municipal solid waste incinerators with high dioxin emission levels in Japan.

BACKGROUND: Great public concern about health effects of dioxins emitted from municipal solid waste incinerators has increased in Japan. This paper investigates the association of adverse reproductive outcomes with maternal residential proximity to municipal solid waste incinerators. METHODS: The association of adverse reproductive outcomes with mothers living within 10 km from 63 municipal solid waste incinerators with high dioxin emission levels (above 80 ng international toxic equivalents TEQ/m3) in Japan was examined. The numbers of observed cases were compared with the expected numbers calculated from national rates adjusted regionally. Observed/expected ratios were tested for decline in risk or peak-decline in risk with distance up to 10 km. RESULTS: In the study area within 10 km from the 63 municipal solid waste incinerators in 1997-1998, 225,215 live births, 3,387 fetal deaths, and 835 infant deaths were confirmed. None of the reproductive outcomes studied here showed statistically significant excess within 2 km from the incinerators. However, a statistically significant peak-decline in risk with distance from the incinerators up to 10 km was found for infant deaths (p=0.023) and infant deaths with all congenital malformations combined (p=0.047), where a "peak" is detected around 1-2 km. CONCLUSION: Our study shows a peak-decline in risk with distance from the municipal solid waste incinerators for infant deaths and infant deaths with all congenital malformations combined. However, due to the lack of detailed exposure information to dioxins around the incinerators, the observed trend in risk should be interpreted cautiously and there is a need for further investigation to accumulate good evidence regarding the reproductive health effects of waste incinerator exposure.

Cigarette smoking as a risk factor for stroke death in Japan: NIPPON DATA80.

BACKGROUND AND PURPOSE: Some previous Japanese cohort studies failed to show an association between smoking and stroke risk. Because such an association has been noted in other populations, this issue should be re-examined in a recent representative Japanese cohort with a higher total cholesterol level. METHODS: A total of 9638 men and women aged 30 years and older without a history of cardiovascular disease (CVD) at baseline in 1980 were followed-up for 14 years. RESULTS: We observed 203 stroke deaths (107 cerebral infarctions, 45 cerebral hemorrhages, and 51 others), 191 heart disease deaths, and 413 CVD deaths. The average serum total cholesterol level was approximately 4.91 mmol/L. Cox proportional hazard ratios were calculated adjusting for age, systolic blood pressure, and other conventional risk factors. The hazard ratios for men who smoked 1 to 20 cigarettes/day for all strokes, cerebral infarction, and cerebral hemorrhage were 1.60 (95% CI, 0.91 to 2.79), 2.97 (CI, 1.27 to 6.98), and 0.42 (CI, 0.16 to 1.09), respectively, and for those who smoked > or =21 cigarettes/day, they were 2.17 (CI, 1.09 to 4.30), 3.26 (CI, 1.11 to 9.56), and 0.68 (CI, 0.20 to 2.33), respectively. For women who smoked > or =21 cigarettes/day, the hazard ratio for all strokes was 3.91 (CI, 1.18 to 12.90). For CVD, all heart disease, and ischemic heart disease, the hazard risks of smoking were significant (1.49 to 4.25) for men but not significant for women. CONCLUSIONS: Smoking in a cohort with moderate serum total cholesterol level was a potent risk factor for stroke, especially cerebral infarction, for both men and women, and for CVD and ischemic heart disease for men.

Cigarette brand preferences of smokers among university students in Japan.

BACKGROUND: A survey on smoking behavior and relating factors among university students is necessary for establishing antismoking measures toward younger generation. To determine brand preferences of young smokers, we conducted a cross-sectional survey for students in a university. METHODS: An anonymous questionnaire was completed by the students at their annual health examinations. A total of 5688 students out of 7136 responded this survey (79.7%). The questionnaire included questions about smoking status, number of cigarettes smoked, brand preference, etc. RESULTS: Smoking prevalence was 55.2% for males and 12.0% for females. Estimated consumption of Japanese-brand cigarettes was 46.8% for males and 36.1% for females, whereas that of American-brand cigarettes was 36.3% for males and 45.1% for females. These values are much higher than the market share of imported cigarettes in Japan (17.1% in 1992). Five American brands ranked in the top 10 brands among these university students, whereas only one American brand was ranked in the top 10 brands in the Japanese market in 1992. Smokers who prefer cigarettes with higher nicotine ratings were more likely to have a higher consumption rate than otherwise. CONCLUSIONS: Cigarette brand preference is an important aspect to realize the smoking behavior among young smokers.

Seismic intensity and risk of cerebrovascular stroke: 1995 Hanshin-Awaji earthquake.

INTRODUCTION: No epidemiological data exist concerning the influence of an earthquake on the risk of stroke. Whether the incidence of cerebrovascular stroke increased after the 1995 Hanshin-Awaji earthquake (EQ) in Japan and whether seismic intensity affected stroke risk dose-dependently was examined. METHODS: A retrospective cohort study was conducted among residents, who were living in two towns on the island of Awaji and were participants of the National Health Insurance (NHI) program. The two towns were divided into 11 districts and their respective damage and socioeconomic states were investigated. Reviewing the NHI documents issued before and after the EQ, people who had strokes (9th International Classification of Diseases, codes 430-431 or 433-434.9) were identified. Risk of stroke in relation to the seismic intensities, was assessed with the Cox proportional hazard model. RESULTS: Among subjects aged 40 to 99 years, 45 of 8,758 (0.514%) had a stroke the year before the EQ 72 of 8,893 (0.810%) had a stroke in the first year following the EQ, and 49 of 8,710 (0.566%) had a stroke in the second year following the EQ. In districts where the earthquake's intensity was < or = 9.5 on the modified Mercalli intensity (MMI), compared with the year prior to the EQ, the relative risk (RR) of stroke was 2.4 (95% confidence interval (CI) = 1.1, 5.0) in the first year following the EQ, after adjusting for age, gender, and income. In that year, compared with MMI of < 8.5-9.0, RRs for 9.0-9.5 and > or = 9.5 were 1.6 (CI = 0.9, 2.1) and 2.0 (CI = 1.1, 3.7), respectively (p for trend 0.02). No trend for the RR was observed in the year before the EQ or in the second year following the EQ. CONCLUSION: The incidence of stroke increased in the first year following the EQ. The increase was associated with seismic intensity in a dose-response manner. Results suggest a potential threshold for RR of > or = 2.0 in areas near 9.5 on the MMI scale.

[Japanese national survey of adolescent drinking behavior: comparison between 1996 and 2000 surveys].

This report shows Japanese adolescent drinking behavior from the national surveys conducted in 1996 and 2000. We randomly selected 120 junior high schools and 100 senior high schools nationwide. We requested the cooperation of the principals of these schools and sent questionnaires to each school. Students answered anonymously the questionnaires during school time, and sealed in envelopes by themselves; then teachers collected the envelopes. The questionnaire focused on adolescent drinking behavior. Valid responses numbered 42,798 (1996) and 47,246 (2000) from the junior high schools and 73,016 (1996) and 59,051 (2000) from the senior high schools. The number of students surveyed represented about 1% of all Japanese junior high school students, and about 2% of all senior high school students. This report covers only students who gave answers on both drinking frequency and drinking quantity. It compares adolescent drinking behavior between the 1996 and 2000 surveys, such as drinking frequency, drinking quantities, drinking occasions, methods of obtaining alcohol, kinds of alcohol drunk, alcohol-related problems, opinions on the law that prohibits minors under 20 years of age from drinking alcohol, and distribution of drinking status of the subjects by the Quantity-Frequency Scale (QF scale). In a comparison of adolescent drinking behavior between the 1996 survey and 2000 survey, non-drinkers among junior high school students increased from 45% to 55%, and those among senior high school students increased from 27% to 33%. On the other hand, ratios of female students in both junior and senior high schools who drank 1 or more times per week were higher in the 2000 survey than in the 1996 survey. Comparison of the 1996 survey and 2000 survey did not indicate that Japanese adolescent drinking has increased or decreased.

Periodic leg movements during sleep in Japanese community-dwelling adults based on the assessments of their bed partners.

BACKGROUND: There is little known about epidemiologic evidence on periodic leg movements during sleep (PLMS) for the Japanese. The present study was a cross-sectional epidemiologic study to estimate the prevalence of PLMS and examine the associated factors of PLMS in Japanese community-dwelling adults. METHODS: The subjects were 884 with bed partners or bedroom mates of 1,889 Japanese adults aged 20 years and over randomly selected from the general population. The case ascertainment of PLMS was based on the assessments of their bed partners or bedroom mates using the Pittsburgh Sleep Quality Index. Multiple logistic regression analyses were used for investigating the associated factors. RESULTS: The age-adjusted prevalences (95% confidence interval) were 5.8% (4.7-6.8%) and 1.3% (0.8-1.9%) for 1 to 2-times, and 3-times or greater of PLMS per week during the preceding month, respectively. Those with PLMS were more likely to experience difficulty in initiating sleep, snore during sleep, be depressed, and suffer from peptic ulcer. Sex, age, difficulty in maintaining sleep, excessive daytime sleepiness, medication use to aid sleep, and any psychoactive substances (tobacco, alcohol, and caffeine) were not identified as significant associated factors of PLMS. CONCLUSIONS: The results suggest that the prevalence of PLMS in Japanese community-dwelling adults is not so high as those reported from Western countries, and that PLMS is correlated with some sleep and health disturbances.

[Study on factors for caries and infant feeding characteristics in children aged 1.5-3 years in a Kanto urban area].

PURPOSES: Generally, the incidence of caries in infants is decreasing, but the volume for children age 3 at Nakahara Ward in Kawasaki City is nearly 5 times higher than that of children at one year and 6 months of age (age 1.5). Here, we investigated the risk factors for cariogenesis during the period from age 1.5 till age 3, focusing on the household environment, lifestyle, diary habits and dental hygiene behavior. METHODS: A total of 491 children who had no caries at periodical health check at age 1.5 were chosen as subjects from those undergoing health check at our Public Health Center. The health check data at ages 1.5 and age 3 along with findings from the questionnaire survey at age 3 were analyzed by with reference to the presence or absence of caries in children at age 3. Odds ratios and 95% confidence intervals (CI95) were first estimated for each risk factor to identify those highly correlated to cariogenesis. Then, logistic regression analysis was performed after adjustment for mutual correlation among the factors. RESULTS: The risk factors significantly correlated to cariogenesis during ages 1.5-3 were maternal feeding at age 1.5 (Odds ratio: 2.80, CI95: 1.42-5.57) and sweet intake of sweets 3 times or more everyday at age 3 (Odds ratio: 2.07, CI95: 1.24-3.43). Moreover, the lack of nightly teethbrushing by parents appeared linked with cariogenesis, (Odds ratio: 1.68, CI95: 0.90-3.14), albeit without statistical significance. CONCLUSION: The present results indicate that caries is likely to be increased when maternal feeding is prolonged to age 1.5 and by consumption of sweets more than 3 times a day at age 3.