1. Cynthia B, Lloyd CB; National Research Council. Executive summary: growing up global: the changing transitions to adulthood in developing countries. Washington, D.C: National Academies Press; 2005. p 25-33.
2. Tolman DL, Striepe MI, Harmon T. Gender matters: constructing a model of adolescent sexual health. J Sex Res 2003;40:4-12. PMID:
12806527
4. Teitler JO. Trends in youth sexual initiation and fertility in developed countries: 1960-1995. Ann Am Acad Pol Soc Sci 2002;580:134-152.
5. Wellings K, Collumbien M, Slaymaker E, Singh S, Hodges Z, Patel D, et al. Sexual behaviour in context: a global perspective. Lancet 2006;368:1706-1728. PMID:
17098090
6. Warren CW, Kann L, Small ML, Santelli JS, Collins JL, Kolbe LJ. Age of initiating selected health-risk behaviors among high school students in the United States. J Adolesc Health 1997;21:225-231. PMID:
9304453
7. Kwon H, Kang HC, Lee JH. Sexually transmissible infections in middle and high school students: experience rates, risk factors and relationship with mental health - results from the Korean youth risk behaviour web-based survey. Sex Health 2016;13:29-34. PMID:
26498016
8. Garriguet D. Early sexual. Health Rep 2005;16:9. PMID:
15971512
11. Barone C, Ickovics JR, Ayers TS, Katz SM, Voyce CK, Weissberg RP. High-risk sexual behavior among young urban students. Fam Plann Perspect 1996;28:69-74. PMID:
8777942
12. Meier AM. Adolescent first sex and subsequent mental health. Am J Sociol 2007;112:1811-1847.
14. Melchert T, Burnett KF. Attitudes, knowledge, and sexual behavior of high‐risk adolescents: implications for counseling and sexuality education. J Counse Dev 1990;68:293-298.
15. Zabin LS, Clark SD Jr. Why they delay: a study of teenage family planning clinic patients. Fam Plann Perspect 1981;13:205-217.
16. Kuh D, Shlomo YB. A life course approach to chronic disease epidemiology. 2nd. Oxford: Oxford University Press; 2004. p 7-10.
17. Kim SJ, Kim IO. The effect of video and discussion-based intervention on the adolescents knowledge and attitude toward sexuality. J Korean Health Stud Assoc 2004;30:85-95 (Korean).
18. Park SW. Health behaviors among adolescents in the rural area in Korea. J Agric Med Community Health 2009;34:202-213 (Korean).
19. Lee IS, Choi GY, Cha SH, Park HY, Lee JJ. A survey on the sexual behavior of adolescents in South Korea: the third survey in 2007. Korean J Obstet Gynecol 2010;53:512-519 (Korean).
20. Szklo M, Nieto FJ. Epidemiology: beyond the basics. 3rd. Burlington: Jones & Bartlett Learning; 2014. p 4-13.
21. Palmore E. When can age, period, and cohort be separated? Soc Forces 1978;57:282-295.
22. Jee Y, Oh CM, Shin A. Recent decrease in colorectal cancer mortality rate is affected by birth cohort in Korea. Asian Pac J Cancer Prev 2015;16:3951-3955.
23. Clayton D, Schifflers E. Models for temporal variation in cancer rates. I: age-period and age-cohort models. Stat Med 1987;6:449-467.
24. Clayton D, Schifflers E. Models for temporal variation in cancer rates. II: age-period-cohort models. Stat Med 1987;6:469-481.
26. Choi Y, Kim Y, Park SK, Shin HR, Yoo KY. Age-period-cohort analysis of female breast cancer mortality in Korea. Breast Cancer 2006;13:266-271.
27. Robertson C, Gandini S, Boyle P. Age-period-cohort models: a comparative study of available methodologies. J Clin Epidemiol 1999;52:569-583.
28. Ahacic K, Kennison R, Thorslund M. Trends in smoking in Sweden from 1968 to 2002: age, period, and cohort patterns. Prev Med 2008;46:558-564.
29. Kim Y, Choi S, Chun C, Park S, Khang YH, Oh K. Data resource profile: the Korea Youth Risk Behavior Web-based Survey (KYRBS). Int J Epidemiol 2016;45:1076-1076e.
31. de Graaf H, Kruijer H, van Acker J, Meijer S. Sexual health of young people in the Netherlands today. Delft: Eburon Publishing BV; 2012. p 73-77 (Dutch).
32. Habel MA, Dittus PJ, De Rosa CJ, Chung EQ, Kerndt PR. Daily participation in sports and students’ sexual activity. Perspect Sex Reprod Health 2010;42:244-250.
33. Miller KE, Sabo DF, Farrell MP, Barnes GM, Melnick MJ. Athletic participation and sexual behavior in adolescents: the different worlds of boys and girls. J Health Soc Behav 1998;39:108-123.
34. Collins RL, Elliott MN, Berry SH, Kanouse DE, Kunkel D, Hunter SB, et al. Watching sex on television predicts adolescent initiation of sexual behavior. Pediatrics 2004;114:e280. -e289.
35. Soler-Hampejsek E, Grant MJ, Mensch BS, Hewett PC, Rankin J. The effect of school status and academic skills on the reporting of premarital sexual behavior: evidence from a longitudinal study in rural Malawi. J Adolesc Health 2013;53:228-234.
36. Warren CW, Kann L, Small ML, Santelli JS, Collins JL, Kolbe LJ. Age of initiating selected health-risk behaviors among high school students in the United States. J Adolesc Health 1997;21:225-231.
37. Han SH, Lee MS, Lee SH. A study on the sexual behaviors and its related factors of high school students in Seoul area. J Korean Soc Health Educ Promot 2000;17:19-39 (Korean).
38. Felton GM, Bartoces M. Predictors of initiation of early sex in black and white adolescent females. Public Health Nurs 2002;19:59-67.
39. Barone C, Ickovics JR, Ayers TS, Katz SM, Voyce CK, Weissberg RP. High-risk sexual behavior among young urban students. Fam Plann Perspect 1996;28:69-74.
40. Werner-Wilson RJ. Gender differences in adolescent sexual attitudes: the influence of individual and family factors. Adolescence 1998;33:519-531. PMID:
9831869
42. Avery L, Lazdane G. What do we know about sexual and reproductive health of adolescents in Europe? Eur J Contracept Reprod Health Care 2010;15 Suppl 2:S54. -S66.
43. Ramiro L, Windlin B, Reis M, Gabhainn SN, Jovic S, Matos MG, et al. Gendered trends in early and very early sex and condom use in 20 European countries from 2002 to 2010. Eur J Public Health 2015;25 Suppl 2:65-68.
44. O’Donnell L, O’Donnell CR, Stueve A. Early sexual initiation and subsequent sex-related risks among urban minority youth: the reach for health study. Fam Plann Perspect 2001;33:268-275.
45. Coker AL, Richter DL, Valois RF, McKeown RE, Garrison CZ, Vincent ML. Correlates and consequences of early initiation of sexual intercourse. J Sch Health 1994;64:372-377.
46. Teitler JO. Trends in youth sexual initiation and fertility in developed countries: 1960-1995. Ann Am Acad Polit Soc Sci 2002;580:134-152.
47. Lee G. Sexual behaviors and sexual experience of adolescents in Korea. J Korea Acad Ind Coop Soc 2016;17:71-80 (Korean).
48. Kugler KC, Vasilenko SA, Butera NM, Coffman DL. Long-term consequences of early sexual initiation on young adult health: a causal inference approach. J Early Adolesc 2017;37:662-676.
49. Kirby D. Emerging answers, 2007: research findings on programs to reduce teen pregnancy and sexually transmitted diseases. Washington, DC: National Campaign to Prevent Teen and Unplanned Pregnancy; 2007. p 6-9.
50. Jessor R, Jessor SL. Problem behavior and psychosocial development: a longitudinal study of youth. New York: Academic Press; 1977. p 4-5.