Mark Orr

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.

Changing behavioral risk for pregnancy among high school students in the United States, 1991-2007.

PURPOSE After dramatic declines in teen births and pregnancies from 1991 to 2005, teen birth rates in the United States increased in 2006 and 2007. We examined behavioral determinants of these trends and the likely direction of future trends. METHODS Pregnancy risk was estimated based on recent sexual activity, method of contraception used, and method-specific contraceptive efficacy, using data from young women on the national Youth Risk Behavior Survey (N approximately 125,000). Weighted logistic and linear regression were used to test for linear and quadratic (curved) trends over time. RESULTS Between 1991 and 2007, behavioral risk for pregnancy declined, with all of the decline occurring between 1991 and 2003. Improvements in contraceptive use from 1991 to 2003 were found in condom use, nonuse, and use of withdrawal. Recent sexual activity (past 3 months) was unchanged over the entire period, except among black students. Quadratic changes were found in pregnancy risk for black teens and in condom use among all teens and black teens, suggesting that trends had reversed or flattened out. Although no change was found for any behavior between 2003 and 2007, pregnancy risk among sexually active teens demonstrated a borderline increase (p=.06) and small nonsignificant declines were seen for specific contraceptive methods. Pregnancy risk estimated from behavioral data correlated well with actual changes in teen pregnancy rates (1991-2004) and birth rates (1991-2006). DISCUSSION After improvement in the 1990s and early 2000s, trends in behavioral risk for pregnancy appear to have stalled or even reversed among certain groups since 2003. These behavioral trends are consistent with the 2006 and 2007 increases in the teen birth rate. They may well portend further increases in 2008.

Behavioral, biological, and demographic risk and protective factors for new HIV infections among youth in Rakai, Uganda.

Background:Prevalence of HIV infection is considerable among youth, although data on risk factors for new (incident) infections are limited. We examined incidence of HIV infection and risk and protective factors among youth in rural Uganda, including the role of gender and social transitions. Methods:Participants were sexually experienced youth (15–24 years old) enrolled in the Rakai Community Cohort Study, 1999–2008 (n = 6741). Poisson regression with robust standard errors was used to estimate incident rate ratios (IRR) and 95% confidence intervals (CI) of incident HIV infection. Results:HIV incidence was greater among young women than young men (14.1 vs. 8.3 per 1000 person-years, respectively); this gender disparity was greater among teenagers (14.9 vs. 3.6). Beyond behavioral (multiple partners and concurrency) and biological factors (sexually transmitted infection symptoms), social transitions such as marriage and staying in school influenced HIV risk. In multivariate analyses among women, HIV incidence was associated with living in a trading village (adjusted IRR (aIRR) = 1.48; 95% CI: 1.04 to 2.11), being a student (aIRR = 0.22; 95% CI: 0.07 to 0.72), current marriage (aIRR = 0.55; 95% CI: 0.37 to 0.81), former marriage (aIRR = 1.73; 95% CI: 1.01 to 2.96), having multiple partners, and sexually transmitted infection symptoms. Among men, new infections were associated with former marriage (aIRR = 5.57; 95% CI: 2.51 to 12.36), genital ulceration (aIRR = 3.56; 95% CI: 1.97 to 6.41), and alcohol use (aIRR = 2.08; 95% CI: 1.15 to 3.77). Conclusions:During the third decade of the HIV epidemic in Uganda, HIV incidence remains considerable among youth, with young women particularly at risk. The risk for new infections was strongly shaped by social transitions such as leaving school, entrance into marriage, and marital dissolution; the impact of marriage was different for young men than women.

Trends in Sexual Risk Behaviors, by Nonsexual Risk Behavior Involvement, U.S. High School Students, 1991–2007

BACKGROUND Adolescent health risk behaviors often occur together, suggesting that youth involvement with one risk behavior may inform understanding of other risk behaviors. We examined the association between involvement in nonsexual risk behaviors and trends among sexual behaviors. METHODS We analyzed 1991-2007 data (n = approximately 125,000) from the Youth Risk Behavior Survey, a nationally representative survey of high school students in the United States. We categorized students into groups based on lifetime (Lifetime Risk Scale) and recent involvement (Recent Risk Scale) in nonsexual risk behaviors, such as smoking and drug use. We examined each groups prevalence of and trends for four sexual behaviors: ever having had sexual intercourse, having four or more lifetime partners, current sexual activity, and use of contraception at last sex. Data were examined for linear and quadratic (U-shaped) change using logistic regression. RESULTS Sexual behaviors varied considerably between youth engaged in no risk behaviors and those in the highest risk behavior groups: sevenfold for ever having had intercourse (13% vs. 87% in 2007) and threefold for four or more lifetime sexual partners (19% vs. 57%). Despite these differences, trends in sexual risk behaviors among youth engaged in multiple nonsexual risk behaviors and those engaged in few or no risk behaviors were remarkably similar. In contrast, sexual behaviors demonstrated a very different pattern of change from that found or nonsexual behaviors: sexual experience and having multiple sexual partners declined into the early 2000s and then increased, whereas nonsexual behaviors increased over time, peaked in the late 1990 s, and then declined. CONCLUSIONS Youth who engaged in little risk taking and those who engaged in considerable risk taking showed similar trends over time. However, the pattern of changes in sexual and nonsexual risk behaviors were remarkably different, raising questions about the potential impact of interventions that would reduce sexual risk taking by reducing nonsexual risk behaviors. Recent increases in sexual risk behaviors may have ominous implications for prevention of unplanned pregnancy and sexually transmitted infections among youth.

The theory of reasoned action as parallel constraint satisfaction: towards a dynamic computational model of health behavior.

The reasoned action approach, although ubiquitous in health behavior theory (e.g., Theory of Reasoned Action/Planned Behavior), does not adequately address two key dynamical aspects of health behavior: learning and the effect of immediate social context (i.e., social influence). To remedy this, we put forth a computational implementation of the Theory of Reasoned Action (TRA) using artificial-neural networks. Our model re-conceptualized behavioral intention as arising from a dynamic constraint satisfaction mechanism among a set of beliefs. In two simulations, we show that constraint satisfaction can simultaneously incorporate the effects of past experience (via learning) with the effects of immediate social context to yield behavioral intention, i.e., intention is dynamically constructed from both an individual’s pre-existing belief structure and the beliefs of others in the individual’s social context. In a third simulation, we illustrate the predictive ability of the model with respect to empirically derived behavioral intention. As the first known computational model of health behavior, it represents a significant advance in theory towards understanding the dynamics of health behavior. Furthermore, our approach may inform the development of population-level agent-based models of health behavior that aim to incorporate psychological theory into models of population dynamics.

Pregnancy Risk among Black, White, and Hispanic Teen Girls in New York City Public Schools

Disparities in teen pregnancy rates are explained by different rates of sexual activity and contraceptive use. Identifying other components of risk such as race/ethnicity and neighborhood can inform strategies for teen pregnancy prevention. Data from the 2005 and 2007 New York City Youth Risk Behavior Surveys were used to model demographic differences in odds of recent sexual activity and birth control use among black, white, and Hispanic public high school girls. Overall pregnancy risk was calculated using pregnancy risk index (PRI) methodology, which estimates probability of pregnancy based on current sexual activity and birth control method at last intercourse. Factors of race/ethnicity, grade level, age, borough, and school neighborhood were assessed. Whites reported lower rates of current sexual activity (23.4%) than blacks (35.4%) or Hispanics (32.7%), and had lower predicted pregnancy risk (PRI = 5.4% vs. 9.0% and 10.5%, respectively). Among sexually active females, hormonal contraception use rates were low in all groups (11.6% among whites, 7.8% among blacks, and 7.5% among Hispanics). Compared to white teens, much of the difference in PRI was attributable to poorer contraceptive use (19% among blacks and 50% among Hispanics). Significant differences in contraceptive use were also observed by school neighborhood after adjusting for age group and race/ethnicity. Interventions to reduce teen pregnancy among diverse populations should include messages promoting delayed sexual activity, condom use and use of highly effective birth control methods. Access to long-acting contraceptive methods must be expanded for all sexually active high school students.

Understanding Long-Term Diffusion Dynamics in the Prevalence of Adolescent Sexual Initiation: A First Investigation Using Agent-Based Modeling

Time-trends in the prevalence of adolescent sexual initiation exhibit periods of increase, decrease and equilibrium. We attempted to explain, in mechanistic terms, how such dynamics arise by developing an Agent-Based Model. The model assumes that sexual initiation diffuses socially both within and across cohorts. The model behavior matched, qualitatively, the empirical time-trends. The impact of two intervention strategies suggested that the age at which an intervention is implemented effected system behavior as did the choice of which specific subpopulation was targeted. Suggestions for how computational models might be used to explore research questions in developmental science were discussed.

Complex Systems and Health Behavior Change: Insights from Cognitive Science

OBJECTIVE To provide proof-of-concept that quantum health behavior can be instantiated as a computational model that is informed by cognitive science, the Theory of Reasoned Action, and quantum health behavior theory. METHODS We conducted a synthetic review of the intersection of quantum health behavior change and cognitive science. We conducted simulations, using a computational model of quantum health behavior (a constraint satisfaction artificial neural network) and tested whether the model exhibited quantum-like behavior. RESULTS The model exhibited clear signs of quantum-like behavior. CONCLUSIONS Quantum health behavior can be conceptualized as constraint satisfaction: a mitigation between current behavioral state and the social contexts in which it operates. We outlined implications for moving forward with computational models of both quantum health behavior and health behavior in general.

Baseline assessment of community knowledge and attitudes toward drug use and harm reduction in Kabul, Afghanistan.

INTRODUCTION AND AIMS Problem drug use has been identified as a significant public health problem in Afghanistan. The study aim was to assess community knowledge and attitude toward drug use and harm reduction in Kabul, Afghanistan. DESIGN AND METHODS A cross-sectional convenience sample of community representatives of 10 possible professions were recruited, distributed between the 17 Kabul city districts in 2007. A questionnaire measured sociodemographic characteristics and awareness, knowledge, and attitudes toward drug use and harm reduction. Logistic regression and cluster analysis were performed to test for associations with participant attitude. RESULTS Of 210 participants, mean age was 36.7 years. Most (98.6%) were Afghan and employed (87.6%). Most (88.6%) were aware of problem drug use in Afghanistan, primarily attributed to unemployment. The majority of participants agreed that addiction is a disease (88.6%) and believed more and better treatment and vocational training facilities were needed (90.5%). Use of only punitive measures in response to drug use was favoured by few (7.1%) participants. Only 33.3% of participants could correctly identify legal consequences of drug use. DISCUSSION AND CONCLUSIONS Community acknowledgement of problem drug use and support for addiction treatment are present in Kabul, Afghanistan. However, knowledge gaps concerning drug laws and harm reduction should be addressed in efforts to introduce culturally appropriate harm reduction programming.

U. S. / European Differences in Condom Use

[2] Goodman E. Metabolic syndrome and the mismeasure of risk. J Adolesc Health 2008;42:538–40. [3] Daniels SR, Morrison JA, Sprecher DL, et al. Association of body fat distribution and cardiovascular risk factors in children and adolescents. Circulation 1999;99:541–5. [4] Onat A, Hergenc G, Sari I, et al. Elevated LDL-cholesterol level predicts diabetes in centrally obese women but not men: Relative roles of insulin resistance and central obesity. Circ J 2007;71:1463–7. [5] Love-Osborne KA, Nadeau KJ, Sheeder J, et al. Presence of the metabolic syndrome in obese adolescents predicts impaired glucose tolerance and nonalcoholic fatty liver disease. J Adolesc Health 2008; 42:543–8. [6] Huang HL, Lin WY, Lee LT, et al. Metabolic syndrome is related to nonalcoholic steatohepatitis in severely obese subjects. Obes Surg 2007;17(145):1457–63. [7] Hsiao PJ, Kuo KK, Shin SJ, et al. Significant correlations between severe fatty liver and risk factors for metabolic syndrome. J Gastroenterol Hepatol 2007;22:2118–23. [8] Kim SK, Kim HJ, Ahn CW, et al. Hyperleptinemia as a robust risk factor of coronary artery disease and metabolic syndrome in type 2 diabetic patients. Endocr J 2008;55:1085–92. [9] Kowalska I, Straczkowski M, Nikolajuk A, et al. Insulin resistance, serum adiponectin, and proinflammatory markers in young subjects with the metabolic syndrome. Metabolism 2008;57:1539–44. [10] Grundy SM, Cleeman JI, Daniels SR, et al. Diagnosis and management of the metabolic syndrome: An American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation 2005;112:2735–52. [11] Nobili V, Manco M, Ciampalini P, et al. Metformin use in children with nonalcoholic fatty liver disease: An open-label, 24-month, observational pilot study. Clin Ther 2008;30:1168–76. [12] Berenson GS, Srinivasan SR, Bao W, et al. Association between multiple cardiovascular risk factors and atherosclerosis in children and young adults. The Bogalusa Heart Study. N Engl J Med 1998; 338:1650–6. [13] Sondike SB, Kay GA, Emmett ME. Weight loss regimens that control for carbohydrate quality or quantity: A review. Pediatr Diabetes 2008; 9:33–45.