Almost every respondent reported having been educated about STDs (97%), and the major sources of this education were school (70%), parents (52%), friends (31%), doctors/health professionals (22%), and other relatives (21%). Only seven respondents (2%) correctly named all eight major STDs.
Thirty-five respondents (9%) correctly identified the four curable STDs, and 13 (3%) correctly identified the four incurable STDs. Only two people (0.5%) correctly identified all eight major STDs, all four curable STDs, and all four incurable STDs. When asked to name the eight major STDs, 91% of the respondents included HIV; 77%, gonorrhea; 65%, syphilis; 58%, genital herpes; 53%, chlamydial infection; 22%, HPV infection; 22%, trichomonas infection; and 15%, HBV infection. Incorrect infections named were lice (36%), vaginal candidiasis (8%), and bacterial vaginosis (3%). When asked which STD was most common in adolescents and adults in Philadelphia, the answer most commonly given was HIV (46%). Other responses included gonorrhea (18%), chlamydia (10%), genital herpes (7%), and syphilis (5%).
Of the 393 adolescents who attempted to name the eight major STDs, the mean total raw score was 4.03 ± 1.93 (range, 0–8). The raw curable and incurable scores were 1.54 ± 1.30 (range, 0–4) and 1.59 ± 0.89 (range, 0–4), respectively. When we deducted the incorrect answers from these raw scores, the mean total knowledge score was 3.50 ± 1.86 (range, −1 to 8), the mean curable STD knowledge score was 1.27 ± 1.38 (range, −3 to 4), and the mean incurable STD knowledge score was 1.17 ± 1.17 (range, −3 to 4). These adjusted STD knowledge scores were used for the remainder of the analyses.
Subgroup comparisons for total, curable, and incurable STD knowledge scores are presented in Table 2. There were no statistically significant differences in the total, incurable, and curable STD knowledge scores when evaluated by sex and ethnicity. Adolescents with Medicaid insurance had higher total knowledge scores than those who did not know their source of health insurance (Table 2).
Age was somewhat correlated with both total knowledge score (r = 0.31;P < 0.0001) and curable STD knowledge score (r = 0.26;P < 0.0001). Age and incurable STD knowledge score were minimally correlated (r = 0.16;P < 0.002). Ten percent of the variance in total knowledge, 7% of the variance in curable STD knowledge, and 3% of the variance in incurable STD knowledge was explained by age. Total knowledge score increased by 0.33 points per additional year of age; the curable STD knowledge score, by 0.21 points per additional year of age; and incurable STD knowledge score, by only 0.11 points per additional year of age.
Early adolescents had lower scores than middle and/or late adolescents (Table 2). Late adolescents performed better on total knowledge score than did the middle adolescents, but their curability STD knowledge scores did not differ significantly.
Total knowledge scores differed somewhat on the basis of self-perception of STD knowledge; the perceived levels were “a lot” (26%), “average” (56%), “a little” (16%), and “nothing” (1.5%) (Table 2). Those reporting a little STD knowledge performed worse than those reporting a lot and average STD knowledge (Table 2).
When we evaluated the relationship between mean total knowledge scores and self-perception of STD knowledge by sex, we found performance differences only in females (females, “a lot” versus “a little,”P < 0.003; “average” versus “a little,”P < 0.03). No significant differences were found for females in curable and incurable STD knowledge scores. For males, there were no differences between the mean total, curable, and incurable STD knowledge scores of those reporting “a lot,” “average,” and “a little” STD knowledge.
Perceived STD knowledge level was somewhat correlated with total knowledge score (r = 0.23;P < 0.0001). The correlations between self-perceptions of knowledge and curable (r = 0.16;P < 0.002) and incurable (r = 0.18;P < 0.0004) STD knowledge were less.
Participants who reported being educated by multiple sources had higher total knowledge scores than those who listed only one source for their STD education (3.8 versus 3.0;P < 0.0004). In addition, there was a moderate correlation between the number of sources of education listed by an adolescent and his or her total knowledge score (r = 0.34;P < 0.0001). Those adolescents educated by their parents, friends, relatives, school, or other sources (such as books or television) had higher total knowledge scores (mean score range, 3.7–4.4) than those who did not receive education from these sources (range, 3.2–3.5; all P values <0.05). Moreover, those educated by physicians (3.8) did no better than those who did not receive such education (3.5;P = NS) (Table 3).
In constructing models to predict the correlates of high STD knowledge in our sample, we included all independent variables (age, race, sex, insurance, self-perception of STD knowledge, and all sources of STD education). The final model predicting total knowledge score included age (β = 0.27;P < 0.0001), self-perception of STD knowledge (β = 0.41;P < 0.005), and education by a relative (β = 0.97;P < 0.05) or other source (β = 1.0;P < 0.05) as significant variables. However, the model's R2 was small at 0.24. In prediction of curable STD knowledge score, only age (β = 0.19;P < 0.0001) was significant, and in the model predicting incurable STD knowledge score, age (β = 0.09;P < 0.02), self-perception of STD knowledge (β = 0.19;P < 0.05), and race (β = −0.20;P < 0.004) were significant. Again, the R2 values were quite small (curable STD knowledge, 0.13; incurable STD knowledge, 0.09), indicating there are other unmeasured factors explaining STD knowledge scores.
Results of this survey suggest that adolescents have low total knowledge scores, indicating an unacceptably low level of SIECUS level 2 (preadolescent) knowledge. Moreover, their knowledge about curability appears to be even worse, demonstrating poor SIECUS level 3 (early adolescent) STD knowledge. These findings were true even for adolescents older than age 16 years, who should demonstrate level 4 STD knowledge. Our findings mirror those of previous studies, 6–8 although our study is the first to assess knowledge within the context of formal knowledge guidelines.
Although 90% of our respondents named HIV disease as one of the major STDs, fewer than one quarter identified trichomonas infection or HPV infection. The annual incidence of trichomonas infection is second only to that of chlamydial infection in the United States. 2 HPV infection rates are also quite high, as improvements in our diagnostic ability have shown. 9–12 Trichomonas and HPV infections are among the most common curable and incurable STDs, respectively, in the adolescent population. It appears that our participants seem to have little knowledge about the STDs that they are at most risk of contracting. Other authors have suggested that adolescent misconceptions and lack of knowledge about the major non-HIV STDs put them more at risk for consequences of their sexual behaviors. 13 Perhaps we are putting too much emphasis on HIV infection, to the exclusion of educating about the other STDs.
Forty-six percent of our subjects incorrectly identified HIV infection as the most common STD in the Philadelphia area. These findings are similar to those in a study by Mellanby et al, 14 in which 53% of adolescents believed that HIV infection was the most common STD. According to recently reported data from the Centers for Disease Control and Prevention, C trachomatis infection is the most commonly reported STD in our region. 3
These results indicate the hegemony that HIV infection has held in the STD education arena. Because HIV infection has the most dire consequences, we spend the bulk of our resources educating people about how to avoid contracting this illness. It was believed that if teens saw themselves as potentially vulnerable to HIV, they would be motivated to either abstain from intercourse or use barrier methods faithfully to avoid infection. However, perceptions of vulnerability to HIV infection are usually quite low in the adolescent and young adult population. 15–17 As described by van der Velde et al, 18 teens seem to have the optimistic belief that their partners would not have such an infection. When this low perception of vulnerability is added to the relative rarity of HIV infection in the adolescent population in comparison with infections such as those due to Chlamydia or Trichomonas, 2 teens may feel somewhat invulnerable to such a disease. Thus, it is easy for the adolescent to demonstrate high levels of HIV knowledge but have low levels of knowledge about the other more common STDs to which they are more vulnerable—and consequently still practice unsafe sexual behaviors.
Other authors have assessed adolescents’ perceived vulnerability to STDs. 16,19–22 Adolescents seem to rate their vulnerability to STDs as being similar to that of their friends but less than that of adolescents in general. 20,22,23 Thus, they may have social network optimistic bias (perceiving their and their friends’ risk as being lower than the general risk to all adolescents) rather than personal optimistic bias (perceiving their personal risk as being lower than that of their friends).
The majority of the teens in this study were unaware of the most common STDs, and this ignorance affects their perceptions of STD prevalence. If they can name only three or four STDs and do not know which are curable and which are not, they do not have the necessary information to make a valid assessment of their risk of STD infection. Although accurate knowledge alone is insufficient to produce changes in attitude and behavior, it is a necessary component toward an adolescent's developing the motivation to change his or her behavior. 23,24 Moreover, if perceived vulnerability is thought of as a function of the prevalence of STDs in the adolescent's social network and of social network optimistic bias, better educating the adolescent about the more prevalent STDs might reduce the optimistic bias and increase perceptions of vulnerability to infection. We have not yet seen whether improving overall STD knowledge—not just HIV knowledge—might move teens toward sexual risk reduction.
Adolescents have difficulty understanding the potential for asymptomatic STD infection. 6,23 Although a person may be asymptomatically infected with any STD, HSV and HPV infections are extremely likely to be transmitted asymptomatically. 25–29 This illustrates a potential two-level knowledge deficit. The adolescents may not be aware of genital herpes or genital wart infections. In fact, in our study, 42% did not list HSV and 78% did not list HPV. Furthermore, even if they are aware of these infections, they are unlikely to understand the potential for asymptomatic infection with these organisms. Compounding this potential problem is the fact that health care providers rarely screen for HSV or HPV infection during routine sexual health care visits. 30 This combination of knowledge deficit and lack of routine screening may make teens believe that having routine sexual health visits is enough to ensure that they are not at risk for or have not contracted an STD. This is an area for future research.
Consistent with our hypothesis, the older adolescents performed better on the knowledge assessment than did the younger adolescents. However, the increase in knowledge as a function of age was minimal. This may indicate a lack of further learning by the late adolescents, or perhaps the educational resources have not covered the details about the non-HIV STDs that they need to know.
Other factors may explain the better performance of our middle and late adolescents as compared to our younger teens. Older teens are more likely to be sexually active and thus more likely to have had an STD than are younger teens. 6,31,32 Thus, the age-related increase in STD knowledge may be unrelated to education; knowledge level may be due experiential factors (e.g., having contracted an STD) rather than routine sexuality education.
Self-perception of STD knowledge was only minimally correlated with the knowledge scores in this study. Interestingly, another study comparing self-perception of HIV knowledge to scores on an HIV knowledge assessment found that males who reported high HIV knowledge scored lower on the assessment than those who reported moderate knowledge of HIV. This situation was reversed among the adolescent females. 33 Although we did not find a similar pattern between males and females in our study, we did find that there were no differences in mean total knowledge scores between males in the four STD knowledge categories. Only our female subjects had a significant difference in mean total knowledge scores between those knowing a lot or having average knowledge and those knowing a little. The reason for this difference is not clear. It may be that males are more likely to overrepresent their level of STD knowledge. Stevenson suggests that this tendency may be a male overconfidence or “pseudo-confidence” in their sexuality knowledge that relates to male sexual socialization. 33
The majority of our sample had been educated about STDs via one or more sources, most often school and parents. This observation differs from other studies, in which health professionals, friends, and television were the more common sources of STD education and information. 14,34 Our results showed that those educated by their parents, other relatives, friends, and school performed better than those educated by other sources, including physicians. This may be related to time of exposure to the STD messages. Physicians have much less time with the adolescent to teach about STDs than do parents, friends, or even school instructors.
The associations between the independent variables and our adolescents’ STD knowledge scores were quite small. Other unexplored variables seem to be responsible for the majority of variance in our models predicting STD knowledge. Future work should be done to help identify variables more highly correlated to adolescent STD knowledge.
There are several limitations to this study. Our method of knowledge assessment may have more accurately tested respondent recall of STD information than recognition. Recall assessments tend to be more difficult than those relying on recognition. 35 It is possible that if we had chosen a recognition assessment, the STD knowledge scores would have been higher. When teens are weighing the risks and benefits of having unprotected sex, however, their knowledge component of the decision-making process is based on recall and not recognition. If they cannot procure STD knowledge from memory, they will not be able to make an accurate risk assessment. In addition, we did not obtain any information about the respondents’ sexual behaviors and STD history. As has been seen in other studies, 6,32 adolescents who are sexually active and those who have had STDs appear to be more knowledgeable than those who are not sexually active. This lack of information may mask other important correlates of adolescent STD knowledge.
Another potential limitation is our decision to not assess all SIECUS level 3 knowledge (which would have involved assessing knowledge about transmission, symptomatology, diagnostic methods, and curability of STDs). We chose to assess the simplest area of level 3 knowledge by testing knowledge of only STD curability. Our finding of limited curability knowledge suggests that more highly specified STD information—such as about transmission, symptomatology, and diagnostic methods—would not have been known.
We did not test interrater reliability in our adolescent peer educators. However, we were very clear (in instructing them about the assessment questionnaires) about what answers to consider correct and incorrect. We also did not record the number or characteristics of adolescents who declined to participate in this study. Our study sample, then, may differ in some unmeasured way from those teens who opted not to take the assessment. In addition, setting this study within a health care complex may have led to a sample that is not generalizable to other non-health-seeking adolescents. These constraints, however, probably led to an overestimation of general adolescent STD knowledge, because health-seeking teens who agree to participate in a study of STD knowledge are more likely to have greater knowledge than those who have no contact with healthcare professionals or are unwilling to have their knowledge tested (because of embarrassment at their lack of knowledge).
Last, the response options for the question assessing self-perception of STD knowledge may have been imprecise in design. Adolescents’ perceptions of their knowledge level may be, in some measure, dependent on their assessment of their peers’ level of STD knowledge. If they perceive their friends as having “average” levels of STD knowledge, then they may believe that their knowledge level is equivalent and may choose “average” as their response as well. However, if their peers’ STD knowledge level is actually very good, they might inadvertently lower their self-perception of STD knowledge level. Some caution must be exercised, then, in the interpretation of the relation between self-perception of STD knowledge and knowledge scores in this study.
This study illustrates that overall adolescent knowledge of STDs is minimal. Middle and late adolescents, for example, did not reach proficiency even with SIECUS level 2 (preadolescent) knowledge. Current STD education may be overemphasizing HIV infection at the expense of other STDs for which teens are at greater risk. These data suggest that educational efforts may be failing adolescents in either design or execution. Future studies should evaluate the content, sources, and retention of STD knowledge in similar populations of adolescents.
1. National Guidelines Task Force. Guidelines for Comprehensive Sexuality Education. New York: Sexuality Information and Education Council of the United States, 1991.
2. Institute of Medicine, Committee on Prevention and Control of Sexually Transmitted Diseases. The Hidden Epidemic: Confronting Sexually Transmitted Diseases. In: Eng TR, Butler WT, eds. Washington, DC: Academy Press, 1997.
3. Division of STD Prevention. Sexually transmitted disease surveillance, 1997. In: US Department of Health and Human Services, Public Health Service, eds. Atlanta: Centers for Disease Control and Prevention, 1998.
4. Stata Statistical Software. College Station, Texas: Stata Corporation, 1999.
5. SPSS for Windows, Version 9. Chicago: SPSS Incorporated, 1999.
6. Biro FM, Rosenthal SL, Stanberry LR. Knowledge of gonorrhea in adolescent females with a history of STD. Clin Pediatr 1994; 33: 601–5.
7. Yacobi E, Tennant C, Ferrante J, Pal N, Roetzheim R. University students’ knowledge and awareness of HPV. Prev Med 1999; 28: 535–41.
8. Kaiser Family Foundation, MTV, Teen People. What teens know and don't (but should) about sexually transmitted diseases: a national survey of 15 to 17 year-olds. Menlo Park: Kaiser Family Foundation, 1999.
9. Rymark P, Forslund O, Hansson BG, Lindholm K. Genital HPV infection not a local but a regional infection: experience from a female teenage group. Genitourin Med 1993; 69: 18–22.
10. Koutsky L. Epidemiology of genital human papillomavirus infection. Am J Med 1997; 102: 3–8.
11. Jonsson M, Karlsson R, Rylander E, et al. The silent suffering women: a population based study on the association between reported symptoms and past and present infections of the lower genital tract [see comments]. Genitourin Med 1995; 71: 158–162.
12. Hippelainen M, Syrjanen S, Koskela H, Pulkkinen J, Saarikoski S, Syrjanen K. Prevalence and risk factors of genital human papillomavirus (HPV) infections in healthy males: a study on Finnish conscripts. Sex Transm Dis 1993; 20: 321–328.
13. Johnson LS, Rozmus C, Edmisson K. Adolescent sexuality and sexually transmitted diseases: attitudes, beliefs, knowledge, and values. J Pediatr Nurs 1999; 14: 177–185.
14. Mellanby A, Phelps F, Lawrence C, Tripp JH. Teenagers and the risks of sexually transmitted diseases: a need for the provision of balanced information [see comments]. Genitourin Med 1992; 68: 241–244.
15. Dekin B. Gender differences in HIV-related self-reported knowledge, attitudes, and behaviors among college students. Am J Prevent Med 1996; 12: 61–66.
16. Ellen JM, Boyer CB, Tschann JM, Shafer MA. Adolescents’ perceived risk for STDs and HIV infection. J Adolesc Health 1996; 18: 177–181.
17. Zimet GD, DiClemente RJ, Lazebnik R, et al. Changes in adolescents’ knowledge and attitudes about AIDS over the course of the AIDS epidemic. J Adolesc Health 1993; 14: 85–90.
18. van der Velde FW, van der Pligt J, Hooykaas C. Perceiving AIDS-related risk: accuracy as a function of differences in actual risk. Health Psychol 1994; 13: 25–33.
19. Boyer CB, Shafer M, Wibbelsman CJ, Seeberg D, Teitle E, Lovell N. Associations of sociodemographic, psychosocial, and behavioral factors with sexual risk and sexually transmitted diseases in teen clinic patients. J Adolesc Health 2000; 27: 102–111.
20. Rosenthal SL, Lewis LM, Succop PA, Burklow KA, Biro FM. Adolescent girls’ perceived prevalence of sexually transmitted diseases and condom use. J Dev Behav Pediatr 1997; 18: 158–161.
21. Gladis MM, Michela JL, Walter HJ, Vaughan RD. High school students’ perceptions of AIDS risk: realistic appraisal or motivated denial? Health Psychol 1992; 11: 307–316.
22. Rosenthal SL, Biro FM, Cohen SS, Succop PA, Stanberry LR. Parents, peers, and the acquisition of an STD: developmental changes in girls. J Adolesc Health 1995; 16: 45–49.
23. Baker JG, Rosenthal SL. Psychological aspects of sexually transmitted infection acquisition in adolescent girls: a developmental perspective. J Dev Behav Pediatr 1998; 19: 202–208.
24. Hingson RW, Strunin L, Berlin BM, Heeren T. Beliefs about AIDS, use of alcohol and drugs, and unprotected sex among Massachusetts adolescents. Am J Public Health 1990; 80: 295–299.
25. Wald A, Zeh J, Selke S, et al. Reactivation of genital herpes simplex virus type 2 infection in asymptomatic seropositive persons. N Engl J Med 2000; 342: 844–850.
26. Mertz GJ, Benedetti J, Ashley R, Selke SA, Corey L. Risk factors for the sexual transmission of genital herpes. Ann Intern Med 1992; 116: 197–202.
27. Mertz GJ, Schmidt O, Jourden JL, et al. Frequency of acquisition of first-episode genital infection with herpes simplex virus from symptomatic and asymptomatic source contacts. Sex Transm Dis 1985; 12: 33–39.
28. Keller ML, Egan JJ, Mims LF. Genital human papillomavirus infection: common but not trivial. Health Care Women Int 1995; 16: 351–364.
29. Stone KM. Human papillomavirus infection and genital warts: update on epidemiology and treatment. Clin Infect Dis 1995; 20: S91–S97.
30. Clark L. Sexually transmitted disease testing practices of adolescent medicine practitioners. Washington, DC: Society for Adolescent Medicine, 2000.
31. Ventura SJ, Curtin SC, Mathews TJ. Teenage Births in the United States: National and State Trends, 1990–1996. National Vital Statistics System. Hyattsville, Maryland: National Center for Health Statistics, 1998.
32. Andersson-Ellstrom A, Forssman L, Milsom I. The relationship between knowledge about sexually transmitted diseases and actual sexual behaviour in a group of teenage girls. Genitourin Med 1996; 72: 32–36.
33. Stevenson HC, Davis G, Weber E, Weiman D, Abdul-Kabir S. HIV prevention beliefs among urban African-American youth. J Adolesc Health 1995; 16: 316–323.
34. Ramirez JE, Ramos DM, Clayton L, Kanowitz S, Moscicki AB. Genital human papillomavirus infections: knowledge, perception of risk, and actual risk in a nonclinic population of young women. J Womens Health 1997; 6: 113–121.
© Copyright 2002 American Sexually Transmitted Diseases Association
35. Sudman S, Bradburn NM. Asking questions: a practical guide to questionnaire design. In: Fiske DW, ed. The Jossey-Bass Series in Social and Behavioral Sciences. San Francisco: Jossey-Bass, 1982.