John S. Santelli

Global burden of diseases, injuries, and risk factors for young people's health during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

BACKGROUND Young peoples health has emerged as a neglected yet pressing issue in global development. Changing patterns of young peoples health have the potential to undermine future population health as well as global economic development unless timely and effective strategies are put into place. We report the past, present, and anticipated burden of disease in young people aged 10-24 years from 1990 to 2013 using data on mortality, disability, injuries, and health risk factors. METHODS The Global Burden of Disease Study 2013 (GBD 2013) includes annual assessments for 188 countries from 1990 to 2013, covering 306 diseases and injuries, 1233 sequelae, and 79 risk factors. We used the comparative risk assessment approach to assess how much of the burden of disease reported in a given year can be attributed to past exposure to a risk. We estimated attributable burden by comparing observed health outcomes with those that would have been observed if an alternative or counterfactual level of exposure had occurred in the past. We applied the same method to previous years to allow comparisons from 1990 to 2013. We cross-tabulated the quantiles of disability-adjusted life-years (DALYs) by quintiles of DALYs annual increase from 1990 to 2013 to show rates of DALYs increase by burden. We used the GBD 2013 hierarchy of causes that organises 306 diseases and injuries into four levels of classification. Level one distinguishes three broad categories: first, communicable, maternal, neonatal, and nutritional disorders; second, non-communicable diseases; and third, injuries. Level two has 21 mutually exclusive and collectively exhaustive categories, level three has 163 categories, and level four has 254 categories. FINDINGS The leading causes of death in 2013 for young people aged 10-14 years were HIV/AIDS, road injuries, and drowning (25·2%), whereas transport injuries were the leading cause of death for ages 15-19 years (14·2%) and 20-24 years (15·6%). Maternal disorders were the highest cause of death for young women aged 20-24 years (17·1%) and the fourth highest for girls aged 15-19 years (11·5%) in 2013. Unsafe sex as a risk factor for DALYs increased from the 13th rank to the second for both sexes aged 15-19 years from 1990 to 2013. Alcohol misuse was the highest risk factor for DALYs (7·0% overall, 10·5% for males, and 2·7% for females) for young people aged 20-24 years, whereas drug use accounted for 2·7% (3·3% for males and 2·0% for females). The contribution of risk factors varied between and within countries. For example, for ages 20-24 years, drug use was highest in Qatar and accounted for 4·9% of DALYs, followed by 4·8% in the United Arab Emirates, whereas alcohol use was highest in Russia and accounted for 21·4%, followed by 21·0% in Belarus. Alcohol accounted for 9·0% (ranging from 4·2% in Hong Kong to 11·3% in Shandong) in China and 11·6% (ranging from 10·1% in Aguascalientes to 14·9% in Chihuahua) of DALYs in Mexico for young people aged 20-24 years. Alcohol and drug use in those aged 10-24 years had an annual rate of change of >1·0% from 1990 to 2013 and accounted for more than 3·1% of DALYs. INTERPRETATION Our findings call for increased efforts to improve health and reduce the burden of disease and risks for diseases in later life in young people. Moreover, because of the large variations between countries in risks and burden, a global approach to improve health during this important period of life will fail unless the particularities of each country are taken into account. Finally, our results call for a strategy to overcome the financial and technical barriers to adequately capture young peoples health risk factors and their determinants in health information systems. FUNDING Bill & Melinda Gates Foundation.

The measurement and meaning of unintended pregnancy.

Unintended pregnancy combines two aspects of fertility: unwanted and mistimed pregnancies. The personal partnership social and political realities of these two aspects are different and the use of separate categories may better reflect the way women think about a pregnancy. A better understanding of the multiple dimensions of unintended pregnancy also may lead to a better understanding of the consequences of these pregnancies. Likewise better knowledge of the extent of mistiming and perhaps the strength of intentions may be important in understanding health impact. Effective programs to prevent unintended pregnancy must use terms that are familiar to women and must build upon cultural understanding of the problem to be prevented. Research should focus on the meaning of pregnancy intentions to women and the processes women and their partners use in making fertility decisions. It should prospectively address the impact of pregnancy intentions on contraceptive use. Both qualitative and quantitative research have contributed to our understanding of fertility decisionmaking; both will be essential to the creation of more effective prevention programs. (excerpt)

Explaining Recent Declines in Adolescent Pregnancy in the United States: The Contribution of Abstinence and Improved Contraceptive Use

OBJECTIVES We explored the relative contributions of declining sexual activity and improved contraceptive use to the recent decline in adolescent pregnancy rates in the United States. METHODS We used data from 1995 and 2002 for women 15 to 19 years of age to develop 2 indexes: the contraceptive risk index, summarizing the overall effectiveness of contraceptive use among sexually active adolescents (including nonuse), and the overall pregnancy risk index, calculated according to the contraceptive risk index score and the percentage of individuals reporting sexual activity. RESULTS The contraceptive risk index declined 34% overall and 46% among adolescents aged 15 to 17 years. Improvements in contraceptive use included increases in the use of condoms, birth control pills, withdrawal, and multiple methods and a decline in nonuse. The overall pregnancy risk index declined 38%, with 86% of the decline attributable to improved contraceptive use. Among adolescents aged 15 to 17 years, 77% of the decline in pregnancy risk was attributable to improved contraceptive use. CONCLUSIONS The decline in US adolescent pregnancy rates appears to be following the patterns observed in other developed countries, where improved contraceptive use has been the primary determinant of declining rates.

Multiple Sexual Partners Among U.S. Adolescents And Young Adults

CONTEXT Because many teenagers and young adults fail to use condoms correctly and consistently, the number of sexual partners they have is an important risk factor for sexually transmitted diseases, including HIV. Identifying factors that are associated with having multiple partners can help in the design of disease interventions. METHODS Data on 8,450 males and females aged 14-22 who participated in the 1992 Youth Risk Behavior Survey were used to examine the prevalence of and factors associated with young peoples having multiple partners. RESULTS In all, 63% of female respondents and 64% of males were sexually experienced. Among those who had had sex during the three months before the survey, 15% and 35%, respectively, had had two or more partners during that period. At each age, the majority of sexually experienced respondents had had more than one lifetime partner; between ages 14 and 21, the proportion who had had six or more rose from 8% to 31% among females and from 14% to 45% among males. In logistic regression analyses, alcohol use, illicit drug use and young age at first coitus were associated with increased odds that females had had two or more partners in the previous three months, and being married lowered the odds; black or Hispanic race or ethnicity, alcohol use and young age at first coitus increased the odds for males, and being married reduced the odds. As the number of reported alcohol-related behaviors increased, the adjusted proportion of respondents who had recently had multiple partners rose from 8% to 48% among females and from 23% to 61% among men. CONCLUSIONS The strong association between alcohol use and having multiple sexual partners underscores the need to educate young people about the effects of alcohol on partner choice and the risk of infection with sexually transmitted diseases.

Long-Term Health Correlates of Timing of Sexual Debut: Results From a National US Study

OBJECTIVES We explored long-term health consequences of age at sexual initiation and of abstinence until marriage to evaluate empirical support for the claim that postponing sexual initiation has beneficial health effects. METHODS We analyzed data from the 1996 National Sexual Health Survey, a cross-sectional study of the US adult population. We compared sexual health outcomes among individuals who had initiated sexual activity at an early or late age versus a normative age. We also compared individuals whose first sexual intercourse had occurred before versus after marriage. RESULTS Early initiation of sexual intercourse was associated with various sexual risk factors, including increased numbers of sexual partners and recent sexual intercourse under the influence of alcohol, whereas late initiation was associated with fewer risk factors. However, both early and late initiation were associated with sexual problems such as problems with arousal and orgasm, primarily among men. Relationship solidity and sexual relationship satisfaction were not associated with early or late initiation. CONCLUSIONS Early sexual debut is associated with certain long-term negative sexual health outcomes, including increased sexual risk behaviors and problems in sexual functioning. Late initiation was also associated with sexual problems, especially among men. Further research is needed to understand how sexual initiation patterns affect later health outcomes.

Adolescent sexual behavior: estimates and trends from four nationally representative surveys.

CONTEXT Accurate information about trends over time in adolescent sexual behavior is essential to understand changes in adolescent pregnancy and sexually transmitted diseases and to monitor the progress of health promotion activities in the United States METHODS Estimates from the National Survey of Family Growth (NSFG), the National Survey of Adolescent Males (NSAM), the Youth Risk Behavior Survey (YRBS) and the National Longitudinal Study of Adolescent Health (Add Health) were compared. While methodologies and populations varied by survey, adolescents aged 15-17 who attend high school were a common subpopulation among all four. For each survey, the prevalence of sexual intercourse, contraceptive use and multiple sexual partners was measured in this population. RESULTS Trend comparisons fell into four categories. First, some similar significant trends were found across surveys. The proportion of all males and of white males who reported ever having had sexual intercourse decreased significantly, while condom use rose significantly among males in both the NSAM and the YRBS. For such behaviors as ever having had sexual intercourse (among Hispanic males and black females), using the pill and using the condom (among all females) and having four or more lifetime sexual partners (among white males), a significant trend was found in one survey while a similar but nonsignificant trend was found in another. Several trend comparisons were not significant in any survey. Finally, having had intercourse in the past three months (among all males and all females), having had two or more partners in the past three months (for males) and having had four or more lifetime sexual partners (among white females and all males) showed a significant trend in one survey but lacked a parallel nonsignificant trend in another. Prevalence estimates in 1995 differed significantly in at least one comparison of surveys for all behaviors except having four or more lifetime sexual partners (both genders) and having two or more recent sexual partners (females). Gender differences within the YRBS and between the NSFG and the NSAM generally were consistent. CONCLUSIONS Trends over time and gender differences were similar across surveys, underscoring their value for tracking adolescent sexual behaviors. Differences in prevalence estimates across surveys probably result from differences in question wording, diverse interview settings and modes of data collection, and varying statistical power. These findings suggest a need to increase our understanding of how methodologies influence survey response in research on adolescents.

Social Media-Delivered Sexual Health Intervention A Cluster Randomized Controlled Trial

BACKGROUND Youth are using social media regularly and represent a group facing substantial risk for sexually transmitted infection (STI). Although there is evidence that the Internet can be used effectively in supporting healthy sexual behavior, this has not yet extended to social networking sites. PURPOSE To determine whether STI prevention messages delivered via Facebook are efficacious in preventing increases in sexual risk behavior at 2 and 6 months. DESIGN Cluster RCT, October 2010-May 2011. SETTING/PARTICIPANTS Individuals (seeds) recruited in multiple settings (online, via newspaper ads and face-to-face) were asked to recruit three friends, who in turn recruited additional friends, extending three waves from the seed. Seeds and waves of friends were considered networks and exposed to either the intervention or control condition. INTERVENTION Exposure to Just/Us, a Facebook page developed with youth input, or to control content on 18-24 News, a Facebook page with current events for 2 months. MAIN OUTCOME MEASURES Condom use at last sex and proportion of sex acts protected by condoms. Repeated measures of nested data were used to model main effects of exposure to Just/Us and time by treatment interaction. RESULTS A total of 1578 participants enrolled, with 14% Latino and 35% African-American; 75% of participants completed at least one study follow-up. Time by treatment effects were observed at 2 months for condom use (intervention 68% vs control 56%, p=0.04) and proportion of sex acts protected by condoms (intervention 63% vs control 57%, p=0.03) where intervention participation reduced the tendency for condom use to decrease over time. No effects were seen at 6 months. CONCLUSIONS Social networking sites may be venues for efficacious health education interventions. More work is needed to understand what elements of social media are compelling, how network membership influences effects, and whether linking social media to clinical and social services can be beneficial. TRIAL REGISTRATION This study is registered at www.clinicaltrials.govNCT00725959.

50-year mortality trends in children and young people: a study of 50 low-income, middle-income, and high-income countries

BACKGROUND Global attention has focused on mortality in children younger than 5 years. We analysed global mortality data for people aged 1-24 years across a 50-year period. METHODS The WHO mortality database was used to obtain mortality data from 1955 to 2004, by age-group (1-4, 5-9, 10-14, 15-19, and 20-24 years) and stratified by sex. To analyse change in mortality, we calculated mortality rates averaged over three 5-year periods (1955-59, 1978-82, and 2000-04) to investigate trends in deaths caused by communicable and non-communicable diseases and injury. FINDINGS Data were available for 50 countries (ten high income, 22 middle income, eight low income, seven very low income, and three unclassified), grouped as Organisation for Economic Co-operation and Development (OECD) countries, Central and South American countries, eastern European countries and ex-Soviet states, and other countries. In 1955, mortality was highest in the 1-4-year age-group. Across the study period, all-cause mortality reduced by 85-93% in children aged 1-4 years, 80-87% in children aged 5-9 years, and 68-78% in young people aged 10-14 years in OECD, Central and South American, and other countries. Smaller declines (41-48%) were recorded in young men (15-24 years), and by 2000-04, mortality in this group was two-to-three times higher than that in young boys (1-4 years). Mortality in young women (15-24 years) was equal to that of young girls (1-4 years) from 2000 onwards. Substantial declines in death caused by communicable diseases were seen in all age-groups and regions, although communicable and non-communicable diseases remained the main causes of death in children (1-9 years) and young women (10-24 years). Injury was the dominant cause of death in young men (10-24 years) in all regions by the late 1970s. INTERPRETATION Adolescents and young adults have benefited from the epidemiological transition less than children have, with a reversal of traditional mortality patterns over the past 50 years. Future global health targets should include a focus on the health problems of people aged 10-24 years. FUNDING None.

Timing of alcohol and other drug use and sexual risk behaviors among unmarried adolescents and young adults.

CONTEXT Although alcohol and drug use by young people has been associated with sexual risk behavior in some research, detailed data are lacking on the timing of substance use in relationship to sexual risk-taking. METHODOLOGY Cross-sectional data on 7,441 unmarried young people aged 14-22 from the 1992 Youth Risk Behavior Survey (household supplement) were used in the analysis. Alcohol and other drug use at last sexual intercourse, substance use in the past 30 days (recent use), the number of different substances ever used (lifetime use) and age at initiation of alcohol use are examined here. The outcome variables assessed through multivariate regression analyses were condom use at last intercourse and more than one sexual partner in the past three months. RESULTS Failure to use a condom was strongly associated with the lifetime substance-use scale or, alternatively, with age at initiation of alcohol. Once the number of substances ever used was controlled for, neither substance use at last sexual intercourse nor recent use was associated with the likelihood of using a condom at last coitus. Among young men and women, recent substance use and use of either alcohol or drugs at last intercourse were both strongly associated with having had more than one sexual partner in the past three months. For females only, lifetime use also increased the probability of recent multiple partners. CONCLUSIONS The relationships between alcohol and other drug use and two sexual behaviors--condom use and multiple partners-suggest distinct mechanisms of influence and the need for different prevention strategies.

The effectiveness of group-based comprehensive risk-reduction and abstinence education interventions to prevent or reduce the risk of adolescent pregnancy, human immunodeficiency virus, and sexually transmitted infections: two systematic reviews for the Guide to Community Preventive Services.

CONTEXT Adolescent pregnancy, HIV, and other sexually transmitted infections (STIs) are major public health problems in the U.S. Implementing group-based interventions that address the sexual behavior of adolescents may reduce the incidence of pregnancy, HIV, and other STIs in this group. EVIDENCE ACQUISITION Methods for conducting systematic reviews from the Guide to Community Preventive Services were used to synthesize scientific evidence on the effectiveness of two strategies for group-based behavioral interventions for adolescents: (1) comprehensive risk reduction and (2) abstinence education on preventing pregnancy, HIV, and other STIs. Effectiveness of these interventions was determined by reductions in sexual risk behaviors, pregnancy, HIV, and other STIs and increases in protective sexual behaviors. The literature search identified 6579 citations for comprehensive risk reduction and abstinence education. Of these, 66 studies of comprehensive risk reduction and 23 studies of abstinence education assessed the effects of group-based interventions that address the sexual behavior of adolescents, and were included in the respective reviews. EVIDENCE SYNTHESIS Meta-analyses were conducted for each strategy on the seven key outcomes identified by the coordination team-current sexual activity; frequency of sexual activity; number of sex partners; frequency of unprotected sexual activity; use of protection (condoms and/or hormonal contraception); pregnancy; and STIs. The results of these meta-analyses for comprehensive risk reduction showed favorable effects for all of the outcomes reviewed. For abstinence education, the meta-analysis showed a small number of studies, with inconsistent findings across studies that varied by study design and follow-up time, leading to considerable uncertainty around effect estimates. CONCLUSIONS Based on these findings, group-based comprehensive risk reduction was found to be an effective strategy to reduce adolescent pregnancy, HIV, and STIs. No conclusions could be drawn on the effectiveness of group-based abstinence education.