A total of 7500 students were invited to participate in the study; 51 declined. As few students refused to participate in the study, the reasons for refusal were not investigated.
The study involved 7449 volunteers aged 14–24
years (2386 males and 5063 females). We excluded 151 questionnaires from the analysis on the basis of quality control. Thus, 7298 questionnaires were analyzed (4962 females and 2336 males).
Out of 7298 subjects studied, 3334 (2222 females and 1112 males) were in the 14-16-year age-group, 2784 (1908 females and 876 males) were aged between 17 and 19
years, and 1180 (7832 females and 348 males) belonged to the 20–24
year age-group. Out of 7298 subjects studied, 6861 (4659 females and 2202 males) were Italians and 437 (303 females and 134 males) were foreigners.
Since the answers of the foreign students did not differ from those of the Italian students, a combined statistical analysis was performed. Likewise, as no statistically significant differences emerged among the answers given by the students from the five Italian cities, this statistical analysis was also combined.
A total of 55.3% of females (95% CI 53.9 – 56.7) and 52.5% of males (95% CI 50.5 – 54.5) reported regular sexual activity. No statistically significant differences were found on considering gender.
The study considered only subjects who declared regular sexual activity after their sexual debut. However, 21 females and 15 males who declared having had a sexual debut reported irregular sexual activity. These volunteers have been included in the group of subjects “NO regular sexual activity” (Table ).
Regular sexual activity of enrolled subjects, age at sexual debut and subjects with regular sexual activity prior 15th birthday by gender and age-group
Table shows regular sexual activity and age at sexual debut by age-group and gender. It also reports the sexually active subjects who stated regular sexual activity prior to their 15th birthday. The percentage of subjects in each age-group who were sexually active before their 15th birthday was calculated in order to better assess the changes in sexual habits among the young.
With regard to regular sexual activity, a significant (p
0.001) increasing trend in proportions by age was observed in both sexes.
Among females, the mean age at sexual debut was 15.7
1.6 and the median age was 16 (25th
15-17). Among males, the mean age at sexual debut was 15.6
1.6 and the median age was 16 (25th
Comparison of the mean ages at sexual debut among the age-groups of respondents of the same sex was carried out by means of analysis of variance (ANOVA). This revealed a highly significant difference (p
0.001), indicating that, among the subjects who declared sexual activity, younger subjects debuted earlier than their older counterparts. Most females had their first sexual intercourse with a partner 2.4
years older, while males first had intercourse with a partner 0.5
years older (data not shown).
Table shows the characteristics of sexual behaviour by gender and age-group among sexually active subjects. The number of lifetime sexual partners increases with age in both sexes, and males report more multiple partnerships than females. No difference was found in the number of partners prior to the respondent’s 15th birthday, nor in the number of sexual partners in the last year among the different age-groups.
Characteristics of sexual behaviour by gender and age-group among respondents who declared sexual activity
Figure reports the numbers and percentages of males and females, broken down according to the risk of acquiring HPV infection. Among males, 434 (38.2% 95%CI 35.8-40.5), 232 (20.4% 95%CI 18.4-22.3) and 470 (41.4% 95%CI 39.9-43.8) subjects fell into the low-risk, medium-risk and high-risk groups, respectively. Among females, 1479 (55.0% 95%CI 53.1-56.9), 524 (19.5% 95%CI 18.0-20.9) and 686 (25.5% 95%CI 23.8-27.1) subjects fell into the low-risk, medium-risk and high-risk groups, respectively.
Number of males and females in the various HPV risk-groups.
Table shows the percentage of subjects who used a contraceptive method during their sexual debut by gender and age-group. Overall, the use of a contraceptive method at sexual debut was reported by 62.2% (95% CI 59.5-64.9) of males; 58.9% (95% CI 56.1-61.6) indicated using a condom. Among females, 70.3% (95% CI 68.6-72.0) reported using a contraceptive method at sexual debut; 67.2% (95% CI 65.9-69.3) specified using a condom. Moreover, a significant (females: p
0.001; males: p
0.05) increasing trend in proportions of the use of contraceptive methods by age was observed in both sexes.
Use of a contraceptive method during first intercourse and during last year among respondents who declared sexual activity by gender and age-group
With regard to the use of contraceptive methods during the last year, 63.6% (95% CI 60.7-66.5) of males responded affirmatively, and 42.6% (95% CI 39.6-45.6) reported using a condom. Among females, 62.8% (95% CI 60.9-64.7) responded affirmatively: 42.8% (95% CI 40.8-44.7) reported using a condom and 21.2% (95% CI 19.6-22.8) oral contraception.
With regard to the use of a contraceptive method during the last year by gender and age-group, an increasing trend (p
0.05) was observed by age for males (Table ).