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Keywords:

  • Adolescents;
  • contraceptive behaviour;
  • emergency contraceptive pill

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

Please cite this paper as: Gaudineau A, Ehlinger V, Nic Gabhainn S, Vayssiere C, Arnaud C, Godeau E. Use of emergency contraceptive pill by 15-year-old girls: results from the international Health Behaviour in School-aged Children (HBSC) study. BJOG 2010;117:1197–1204.

Objective  To describe emergency contraceptive pill (ECP) use and variation across countries/regions; and to explore personal and contextual factors associated with ECP use and differences across countries/regions.

Design  Data were obtained from 11 countries/regions in the 2006 Health Behaviour in School-aged Children cross-sectional study.

Setting  Data were collected by self-report questionnaire in school classrooms.

Population  The analysis is based on 2118 sexually active 15-year-old girls.

Methods  Contraceptive behaviours were compared across countries/regions by chi-square tests. Individual factors related to ECP use were investigated with separate logistic regression models. Multilevel random-intercept models allowed the investigation of individual and contextual effects, by partitioning the variance into student, school and country/region levels.

Main outcome measures  ECP use at last sexual intercourse.

Results  ECP use rate varied significantly across countries/regions. Poor communication with at least one adult (odds ratio [OR] 1.62 [1.12–2.36], P = 0.011) and daily smoking (OR 1.46 [1.00–2.11], P = 0.048) were independently associated with ECP use in comparison with condom and/or birth-control pill use. Sexual initiation at 14 years or later (OR 2.02 [1.04–3.93], P = 0.039), good perceived academic achievement (OR 1.69 [1.04–2.75], P = 0.035) and daily smoking (OR 1.63 [1.01–2.64], P = 0.045) were associated with higher levels of ECP use in comparison with unprotected girls. The country-level variance remained significant in both comparisons.

Conclusions  These data document the large heterogeneity in rates of ECP use between countries/regions. These differences could not be explained by individual or contextual factors, and raise further questions in relation to ECP access for adolescents and their education in its appropriate use.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

Unintended pregnancies, either mistimed or undesired at the time of conception, are common. For instance, of the 6.4 million pregnancies recorded in 2001 in the United States, approximately half were unintended.1,2 Of the 3.1 million of unintended pregnancies, 44% resulted in births, 42% in induced abortions and 14% in miscarriages. Among women with unintended pregnancies, 48% were using contraceptive methods during the month of conception, although not always correctly. In France,3 one-third of pregnancies are unintended, 42% of them occurred among women using contraceptive methods (21% with birth-control pill, 12% with condom and 9% with intrauterine device). Induced abortions are a frequent outcome during unintended pregnancies and are estimated at 40%.1,2 Unintended pregnancies are also significant among adolescents: in the UK, birth rate in adolescents aged 15–19 years is 29.6% and the induced abortion rate is 21.3%.4

Emergency contraception (EC), so named by the World Health Organization (WHO), comprises drugs with various dosages (the emergency contraceptive pill; ECP) or intrauterine devices used to prevent pregnancy after unprotected sexual intercourse or after a recognised contraceptive failure.5 It has the potential to reduce unintended pregnancy rates, thereby reducing the number of induced abortions. The ECP is the most common EC used and is intended as a back-up method for occasional use, and not as a regular method of contraception. Providing education about ECP use and its accessibility (whether over-the-counter, from a medical provider or pharmacist, or by advance prescription) should be an integral part of women’s health care.6

To our knowledge, in Europe, ECP was available in 2007 without prescription in 12 countries,7 including Belgium, Denmark, Finland, France, Greece, Holland, Latvia, the Netherlands, Portugal and Sweden. In the UK, ECP has been sold without prescription to women over the age of 16 years since 2001, and costs the equivalent of approximately 28€. The price of the ECP is also relatively high in Switzerland (24€). However, in France, where it has been sold since 1999 without a prescription, it costs less than 10€. The availability of ECP is important for adolescents in particular, because unprotected sexual encounters are more common in the early years of sexual activity than among adults.8 Previous research has documented positive associations between ECP awareness and level of parental education9,10 as well as teenagers’ school performance or scholastic curriculum.10–12 Nevertheless, few data have been published regarding ECP use in adolescent populations across countries.

The objectives of this paper are:

  • 1
     To describe ECP use among 15-year-old girls and its variation across some European countries/regions.
  • 2
     To compare ECP users with ‘protected’ and ‘not protected’ girls regarding pregnancies through relevant individual and contextual factors.
  • 3
     To test to what extent differences can be explained by individual and contextual factors.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

Sample

Data were obtained from the Health Behaviour in School-aged Children (HBSC) international WHO collaborative cross-sectional study,13 carried out every 4 years since 1982. This survey aims to better understand health, wellbeing, health behaviours and social conditions of school children aged 11, 13 and 15 years and to examine determinants of health. These data allow the examination of trends in health indicators, and also the testing of research questions relevant to health promotion. Forty-one countries/regions participated in the 2006 cross-national survey sharing a common protocol and using the international standardised questionnaire.14 Of these, 11 (Flemish Belgium, Bulgaria, England, Finland, France, Greece, Hungary, Latvia, Sweden, Ukraine, Wales) decided to ask about ECP among other contraception means.

Among the 8588 girls who completed the item ‘Have you ever had sexual intercourse’, 2200 reported that they were sexually initiated. Thirty-three premenarcheal girls were excluded from this sample because of their absent need for contraception. Analyses were then restricted to girls without missing data about ECP, contraceptive pill or condom use (n = 36 exclusions). Also excluded were those who stated having taken ‘other contraceptive method’ and not having used a birth-control pill, condoms, or ECP (n = 13) because it could not be determined if the method was effective or not. Therefore, the present analysis is based on 2118 15-year-old female students from the 11 countries/regions (Figure 1).

image

Figure 1.  Sample definition.

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Collected data

From the literature,9–12 we hypothesised that family, socioeconomic and school contexts as well as early menarche, sexual activities, psychoactive substance use and life satisfaction could be related to contraceptive behaviour among sexually active 15-year-old girls. These factors were operationalised as described next.

Family context

Family structure (living with both parents/other) and reported ease of communication with adults (parents or step-parents) were used as indicators of family context.

Socio-economic context

Socio-economic context was measured using the ‘Family Affluence Scale’ (FAS) with three levels (low, medium and high affluence) according to its distribution within each country.15

School context

Students were asked about their school experience with responses dichotomised: ‘I don’t like it very much/I don’t like it at all’ versus ‘I like it a bit/I like it a lot’. Students were also asked about their perceived school performance (‘good/very good academic achievement’ versus ‘average and not good’).

Individual factors

Early menarche was defined as menarche before the age of 11,16 and age at first sexual intercourse was dichotomised with age before 14 considered as early sexual initiation.17 Regarding substance use, students were asked about tobacco, cannabis and alcohol intake. Smoking was dichotomised into ‘daily tobacco smokers’ versus others, cannabis use as lifetime use (‘never’ versus others), and alcohol consumption frequency was dichotomised as weekly (‘at least every week’ versus others). Life satisfaction was assessed with the Cantril ladder18 and dichotomised at 6 on the 11-point scale (‘low life satisfaction’ [Cantril <6] versus others). Number of evenings per week spent with friends was dichotomised at four (‘four or more evenings a week’ versus others).

Students were asked about their contraceptive methods during their last sexual intercourse with the response options: birth-control pill, condom or ECP. Girls were categorised into three contraceptive behaviour groups to reflect the efficacy of contraceptive methods used. Girls who reported having used the ECP, irrespective of any other contraception use, were defined as the ‘ECP group’ (n = 185). This group therefore comprised girls using ECP as a primary contraception method and girls using ECP as an adjuvant contraception method in the case of deficiency of regular contraception (for instance condom breakage or birth-control pill misuse). Initial comparisons between girls who used ECP only and those who used ECP as well as pill and/or condom, for all variables that we identified as potentially related to contraceptive behaviour, showed no significant differences at the 5% level, except for life satisfaction, with a significantly higher percentage of high life satisfaction in the ‘ECP only group’ (P = 0.02) (data not shown). Therefore, we collapsed these two subgroups for subsequent analyses. Girls who reported having used a condom and/or birth-control pill at last intercourse were grouped into the ‘protected group’ against pregnancy at last sexual intercourse (n = 1610). Girls who had not used a condom or birth-control pill or ECP were classified as ‘not protected’ against pregnancy at last sexual intercourse (n = 323).

We deliberately focused our analyses on contraception behaviour, therefore, despite its clinical relevance for young people, we did not match incidence of sexually transmitted infections (STIs) to any compared groups (indeed some effective contraception methods including birth-control pill, could not prevent STIs).

Statistical methods

We first examined differences across countries/regions in terms of contraceptive use. The rates of girls reporting use of ECP and birth-control pill, condom, dual protection (birth-control pill and condom) were compared across countries/regions by chi-square tests.

We then investigated individual factors related to the use of ECP. Separate logistic regression models were conducted to compare on the one hand the ‘ECP group’ to the ‘protected group’, and the ‘ECP group’ to the ‘not protected group’ on the other. Multilevel random-intercept models were conducted to take into account the nonindependence of observations inherent to the sampling design (girls being nested within schools and countries/regions). These models allowed us to investigate individual and contextual effects, by partitioning the variance into student-level, school-level and country-level variance.19 We used the Median Odds Ratio (MOR)20–22 to quantify cross-national heterogeneity in the use of the ECP. The MOR can be interpreted as the median OR in the use of the ECP between the country/region at lower risk and the country/region at higher risk when picking all pairs of countries/regions, given the fixed effects. A backward stepwise procedure was used to remove variables from the first model including all students’ characteristics that were significantly related to ECP use at <20% level. This procedure was applied to observations without any missing value on the variables from the first multivariate multilevel model. In the final models, we tested interactions between explanatory variables. Random slopes at the country level were also tested to determine whether the effect of the independent individual characteristics had different effects across countries/regions. The likelihood of the final multivariate multilevel model was compared with the likelihood of the same model without the country-level random intercept to test whether cross-national variations were still significant after adjustment for individual risk factors. We applied the same method to test for the significance of inter-school variations after adjustment for individual risk factors.

Statistical analyses were conducted with Stata 9.0.23 The gllamm command was used to run the multilevel logistic models.24 For all the analyses, the confidence level was set at 0.05.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

Description of contraceptive behaviours

Among the 8588 girls without missing data on the item ‘Have you ever had sexual intercourse’, 25.6% reported that they were sexually initiated. The frequency of sexually active girls varied from 17.2% in Greece to 40.6% in Wales.

Contraceptive behaviours are described for 2118 (98.0%) of the sexually initiated and menstruating girls (Table 1). The percentage of respondents declaring that they had used ECP at their last sexual intercourse significantly varied across countries/regions, from 1.7% in Hungary to 17.8% in France (P < 0.001). The ECP was the only contraceptive method in 18.4% of the girls whereas it was associated with birth-control pill, condom or both in 5.4%, 56.2% and 20.0% of the girls, respectively.

Table 1.   Emergency contraceptive pill (ECP) and contraceptive use at last sexual intercourse among already menstruated and sexually initiated 15-year-old girls (n = 2118), by country/region
Country/regionECP usersProtected girls* (without ECP)Not protected girls**
ECP onlyECP + effective contraception*TotalBirth-control pill onlyCondom onlyDual protection*TotalTotal
 nnnn (%)nnnn (%)n (%)
  1. *Birth-control pill or condom.

  2. **Neither birth-control pill, nor condom, nor ECP.

Flemish Belgium17841923 (12.9)446052146 (82.0)9 (5.1)
Bulgaria2553912 (4.7)118111193 (75.7)50 (19.6)
England19522022 (11.3)2010924153 (78.5)20 (10.3)
Finland2426612 (5.0)5212424200 (82.6)30 (12.4)
France23683442 (17.8)2412028172 (72.9)22 (9.3)
Greece115167 (6.1)169575 (65.2)33 (28.7)
Hungary116112 (1.7)877893 (80.2)21 (18.1)
Latvia107268 (7.5)577688 (82.2)11 (10.3)
Sweden23131518 (7.8)4411716177 (76.6)36 (15.6)
Ukraine19011213 (6.8)21114117 (61.6)60 (31.6)
Wales25332326 (10.3)2811949196 (77.5)31 (12.3)
Total211834151185 (8.7)22911542271610 (76.0)323 (15.3)

Factors associated with ECP use

Comparison of the ‘ECP group’ with the ‘protected group’ 

The multivariate models were applied to a restricted sample of 1572 students without missing data on the variables included in the first multivariate model, which included 168 girls who reported that they used the ECP at their last sexual intercourse (see Figure 1, Table 2). In the final model, poor communication with at least one adult (OR 1.62 [1.12–2.36], = 0.011) and daily smoking (OR 1.46 [1.00–2.11], P = 0.048) were independently associated with a higher risk of ECP use when compared with ‘protected’ girls. Even though not significantly related to the outcome (OR 1.35 [0.91–2.00], P = 0.138), the final model was controlled for lifetime cannabis experimentation, because of its confounding effect on daily tobacco use.

Table 2.   Distribution of contextual and individual factors by contraceptive-use groups, all countries/regions
 ‘ECP’ (n = 185)‘protected’(n = 1610)‘not protected’(n = 323)‘ECP’ versus ‘protected’‘ECP’ versus ‘not protected’
n (%)n (%)n (%)P value*P value*
  1. ‘Protected’: birth-control pill and/or condom.

  2. ‘Not protected’: neither birth-control pill nor condom.

  3. *P value from multilevel logistic model, adjusted for clustering within countries/regions and schools. In italic: P value for global Wald test; in bold: significant at the 0.05 level.

Sexual initiation
Before 14 years old27 (14.7)229 (14.3)61 (19.1)0.8310.067
14 years old or older157 (85.3)1367 (85.7)259 (80.9)
Age at menarche
≥11 years old173 (94.5)1477 (94.0)295 (94.3)0.4900.620
<11 years old10 (5.5)94 (6.0)18 (5.7)
Family structure
Both parents101 (54.5)954 (59.7)185 (57.6)0.3390.831
Other81 (44.5)643 (40.3)136 (42.4)
Family affluence scale
High64 (35.0)533 (33.7)83 (26.0)0.4860.786
Medium49 (26.8)361 (22.9)70 (21.9)0.8530.711
Low70 (38.2)686 (43.4)166 (52.1)0.2560.488
Ease of communication
With at least 1 adult125 (67.9)1269 (79.4)244 (75.5)0.0040.570
With no adult59 (32.1)329 (20.6)79 (24.5)
Daily smoking
No88 (50.0)953 (62.0)184 (59.0)0.0020.017
Yes88 (50.0)585 (38.0)128 (41.0)
Life time use of cannabis
No93 (52.2)989 (66.4)192 (64.2)0.0090.709
Yes85 (47.8)501 (33.6)107 (35.8)
Weekly drinking
No100 (54.0)942 (58.5)167 (51.7)0.1510.417
Yes85 (46.0)668 (41.5)156 (48.3)
Liking school
No91 (49.2)654 (40.9)161 (50.2)0.0990.360
Yes94 (50.8)945 (59.1)160 (49.8)
Academic achievement
Good or very good81 (43.8)749 (47.0)129 (40.3)0.6260.131
Average or below average104 (56.2)846 (53.0)191 (59.7)
Life satisfaction
High137 (74.0)1223 (76.0)222 (68.7)0.6460.090
Low48 (26.0)387 (24.0)101 (31.3)
Evenings with friends
<4 per week101 (54.6)874 (55.2)179 (55.8)0.2410.064
≥4 per week84 (45.4)709 (44.8)142 (44.2)

The MOR, reflecting cross-national variation, was 1.52 in the first crude model to obtain estimates of variance components. This was slightly reduced to 1.42 by the introduction of contextual and individual factors into the model. However, the country-level variance remained significantly different from 0 (= 0.012 for the likelihood ratio test).

Comparison of the ‘ECP group’ to the ‘not protected group’ 

The three-level random intercept models were based on a sample of 480 girls, of whom 175 had reported ECP use after their last sexual intercourse. The final multilevel model indicated that later sexual initiation (OR 2.17 [1.11–4.23], P = 0.024), perceived good academic achievement (OR 1.69 [1.04–2.75], P = 0.035) and daily smoking (OR 1.95 [1.20–3.17], P = 0.007) increased the likelihood of ECP use compared with being unprotected against pregnancy.

In the crude model the MOR estimate was 2.46, indicating country-level heterogeneity. In the final model taking into account the individual variables, the country-level variance remained significantly different from 0 (P < 0.001 for the likelihood ratio test) at 2.71.

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

From our results, individual factors associated with ECP use at last sexual intercourse varied according to the group comparison (either ‘protected’ or ‘not protected’) but could not explain in total the significant country-level variation of ECP use.

Description of contraceptive behaviours

Analyses of the 2001/02 HBSC survey have reported that a quarter of 15-year-old girls had engaged in sexual intercourse, and that condoms were the most frequent method of contraception at last intercourse (73.9%) reported by the sexually active respondents, followed by the dual use of condoms and contraceptive pills (15.7%), and contraceptive pills only (8.4%).25 Analyses of the 2005/06 HBSC survey documented an increase in appropriate contraceptive use.26 However, an important minority (15.3% on average) is still at risk of pregnancy and STIs, health problems of particular relevance in adolescent populations. Previous studies have shown in general a decline in adolescent pregnancy rates, so the reported increase of incidence in STIs over the past 10 years is remarkable, despite large discrepancies in rates among countries for both issues.27 Indeed, our results highlight a problem in youth contraception in Europe. Similar challenges have been described in other regions. In the USA, at first sexual intercourse, many sexually active teenagers did not use contraception at all (26% of young women aged 15–19 years did not use any method of contraception28,29) or used less effective methods. The most popular contraceptive method for teenagers remained the condom, yet only 28% of girls reported using condoms every time they had sexual intercourse. For some authors,28,29 the lack of information given to teenagers regarding contraception is highlighted as a key factor in understanding these findings.

Despite these high rates of unprotected intercourse, only 8% of teenagers have used ECP in the USA in recent years.28,29 In Europe, life-time ECP use ranged from 10% in England to 28% in Sweden9,11,30–33 among sexually active girls aged 14–20 years. Higher rates of ECP use in France can be partly explained by a national health policy: the introduction in 1999 of ECP availability without prescription and free for those under 18 years resulted in a 72% increase in use.34,35

The ECP was targeted to compensate for inconsistent contraceptive use or contraceptive errors.35 Nevertheless, some women use it as a regular method of contraception:11 in a representative cohort of French women of reproductive age (18–44 years), 15% of ECP use instances were reported by women using no other method of contraception. In our sample of 15-year-olds, 22.5% of ECP use was not associated with another contraceptive method.

Factors associated with ECP use

There is limited information available on the associations between lifestyle factors and ECP use in adolescence. Stewart et al.36 conducted a retrospective chart review (n = 182) to determine whether young women aged 13–21 years seeking ECP at an adolescent health clinic had different health histories and gynaecological outcomes from adolescents seeking routine reproductive health care at the same clinic. On the year before enrolment, ECP users were less likely to have had a pelvic examination and Papanicolaou smear than girls in the control group. There was no significant difference in pregnancy rates between the groups, and the control group had a higher incidence of Chlamydia colonisation than the ECP group. In a Swiss study by Ottesen et al.,11 ECP use was higher in girls with more than three partners, first ‘love affair’ before 14 years, regular sexual intercourse, unplanned first intercourse and a history of pregnancy. The differences between these study findings may be explained by differences in the comparison groups: whereas Stewart et al.36 compared ECP use with effective contraception use, Ottesen et al.11 compared ECP users with non-users. In our study, we compared ECP use with both different contraceptive behaviours (effective contraception methods and no protection at all). As expected, ECP use was associated with different variables according to the comparison group definition. ECP use was associated with daily smoking and poor communication with at least one adult when compared with effective contraception use, whereas when compared with not-protected girls, ECP users were more likely to be found among those having had first sexual intercourse at 14 years or older, with good academic achievement and being a daily smoker. In the latter comparison, no significant association with family or socioeconomic contexts was identified.

Another important finding is the country-level variance as represented by the MOR. Once individual factors were considered the country-level variance remained significant, underscoring the important heterogeneity between participating countries/regions. Furthermore, as random slopes did not significantly vary across countries/regions, we did not reject the hypothesis that the independent variables in the final models had identical effects across countries/regions. Therefore the contextual and individual factors included in this study did not explain the differences between countries/regions. It may be that either other individual or contextual factors not tested here explain ECP use, or that it is more strongly influenced by national public-health policies and their implementation. The fact that 17.8% of girls reported that they have used ECP in France, where ECP is available over-the-counter, at no cost for under 18s, and even available from school nurses, as opposed to an overall rate of 8.7% in the other countries of our sample is in favour of the latter hypothesis. For some, this easy access represents a plebiscite for sexual initiation or unprotected intercourse. Nevertheless, France has one of the higher rates of girls using condoms and/or birth-control pills, so easier ECP access does not seem to encourage girls to not protect themselves against pregnancy.

Our results should be interpreted with caution because data on contraceptive behaviour were limited to last sexual intercourse. Nevertheless, research has shown that adolescents have difficulty in summarising their use of contraceptives, even for short time periods. In addition, if asked about ‘typical’ behaviour, respondents are more likely to bias their answers by describing what they consider to be socially desirable. Therefore, responses about the ‘last’ intercourse have higher reliability and validity than those about ‘typical’ behaviour.37 Furthermore, data excluded missing values for 349 girls on sexual initiation and 36 girls on contraceptive behaviour; this raises possible concerns on our samples’ representativeness. Nevertheless, those girls did not significantly differ from the 2118 others on family structure, FAS, early sexual initiation, early menarche, daily tobacco use, lifetime use of cannabis, weekly alcohol consumption, liking school, academic achievement and life satisfaction (data not shown). Therefore, we considered that our results were not likely to be strongly biased.

Conclusion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

Though contraceptive behaviours differed between countries/regions, the geographical heterogeneity could not be explained by differences in individual factors related to ECP use. These findings emphasise the need for further international studies on sexual behaviours and contraceptive use of young people, with accurate country-level data such as availability of contraception, sexual health educational policy, as pregnancy regulation and prevention of STIs among young people remain major challenges for reproductive and sexual health promotion.

Contribution to authorship

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

A.G. had full access to all of the data in the study; he participated in the statistical analyses and wrote the manuscript. V.E. took the responsibility for the integrity of the data and the accuracy of the data analyses. E.G. and S.N.G. conceived of the study, made substantial contributions to interpretation of data and co-wrote the manuscript. C.A. contributed to the analysis and interpretation of data, and co-wrote the manuscript. C.V. made substantial contributions to interpretation of data. All authors read and approved the final manuscript.

Details of ethics approval

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

The HBSC requires from its participant that they obtain approval to conduct the survey from the relevant ethics review board or equivalent regulatory institution at country level.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References

The HBSC is an international study carried out in collaboration with WHO/EURO. The international coordinator of the 2005/06 study was Professor Candace Currie, University of Edinburgh, UK; and the data bank manager was Professor Oddrun Samdal, University of Bergen, Norway. The Principal Investigators of the studied countries/regions are Dr Carine Vereecken (Belgium), Dr Lidiya Vasileva (Bulgaria), Mr Antony Morgan (England), Dr Jorma Tynjälä (Finland), Dr Emmanuelle Godeau (France), Professor Anna Kokkevi (Greece), Dr Ágnes Németh (Poland), Dr Iveta Pudule (Latvia), Dr Lilly Eriksson (Sweden), Dr Olga Balakireva (Ukraine) and Mr Chris Roberts (Wales). A complete list of the participating researchers can be found on the HBSC website (http://www.HBSC.org).

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Conclusion
  8. Disclosure of interests
  9. Contribution to authorship
  10. Details of ethics approval
  11. Funding
  12. Acknowledgements
  13. References
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