Dramatic rise in plasma viremia after CD8(+) T cell depletion in simian immunodeficiency virus-infected macaques.

To determine the role of CD8(+) T cells in controlling simian immunodeficiency virus (SIV) replication in vivo, we examined the effect of depleting this cell population using an anti-CD8 monoclonal antibody, OKT8F. There was on average a 99.9% reduction of CD8 cells in peripheral blood in six infected Macaca mulatta treated with OKT8F. The apparent CD8 depletion started 1 h after antibody administration, and low CD8 levels were maintained until day 8. An increase in plasma viremia of one to three orders of magnitude was observed in five of the six macaques. The injection of a control antibody to an infected macaque did not induce a sustained viral load increase, nor did it significantly reduce the number of CD8(+) T cells. These results demonstrate that CD8 cells play a crucial role in suppressing SIV replication in vivo.

Conceptions of illness in young adolescents.

This study examined conceptions of illness in young adolescents. A group of 77 urban junior high school students aged 11 to 15 years were asked for their definitions of illness. Themes occurring in definitions of illness were identified and coded according to a previously developed coding scheme. Evidence in support of a developmental process underlying conceptions of illness was found by examining adolescents' definitions and comparing them with child and adult norms established in prior research. Results for adolescents showed the frequency of use of specific themes to fall between child and adult norms. The strongest evidence in support of a developmental trend was seen in definitions of illness pertaining to changes in daily activities. However, the relative frequency of adolescents' definitions was more like that of children than adults, indicating that whereas adolescents used a greater frequency of adult-like themes, they did so within a framework more descriptive of children. Qualitative aspects of definitions of illness showed age-linked differences with adolescents generating more adult-like, conceptually sophisticated definitions than children. In addition to developmental differences, similarities in definitions of illness were also found; among all age groups the most common delineators of illness were physical symptoms. Psychosocial themes were less frequently mentioned. Clinicians who discuss with their adolescent patients the ways in which illness affects social interaction may be communicating more effectively than practitioners who focus solely on signs and symptoms of physical disease.

Health consequences of behaviors: injury as a model.

Injury is the third leading cause of death in the United States and the leading cause for children, adolescents, and young adults. Injury results from multiple factors and so may its prevention. The first and simplest approach toward preventing injuries has been to innovatively and aggressively apply a traditional public health model. Strategically, the goal has been to remove harmful agents of injury and to make the environment safer. Tactics such as public information, product regulation, legislative action, and the like have been credited with reductions in mortality and morbidity. To expand our understanding and our prevention strategies across multiple injuries, other scientific knowledge bases and intervention models from fields such as psychology and child development are being used to study childhood injury. These approaches show that in addition to environmental determinants, psychosocial factors involving both the care giver and the child are related to injury. The research programs described here illustrate the advantage of investigating psychosocial factors at both molar and molecular levels. General characteristics of mothers and children related to injury help define families at risk, as well as suggesting vehicles for intervention. Behavioral factors influencing risk perception highlight the etiology of increased risk in adolescence. Injury episodes, even slight, as well as "near injuries" and dangerous and risky behavior can be quantified and analyzed by retrospective ("postmortem") approaches yielding data on commonly occurring consequences (and the lack thereof) for minor injury. Finally, approaches that simulate dangerous situations can identify interaction patterns that result in childhood injury. Based on such research, we are coming to view injuries as the result of patterns of behaviors that develop and persist over time, and as such these patterns can be detected and, one hopes, altered before a serious medical event occurs. The role of the pediatrician after injury occurs is clear. With regard to prevention of injuries, pediatricians' roles are being defined by those individuals who have begun to investigate causes, educate families, and advocate for regulation and prevention. However, like the causes and methods for prevention, the disciplines involved in the study and prevention of injury are multiple. Such a multidisciplinary approach that considers multiple factors, theories, models, and interventions to prevent injury may be the approach that is as simple as possible.

Appointment-keeping behavior in adolescents: factors associated with follow-up appointment-keeping.

STUDY OBJECTIVES: To identify the sociodemographic and Health Belief Model predictors of follow-up appointment-keeping behavior. DESIGN: Prospective observational study. SETTINGS: General adolescent medical clinic. PATIENTS AND MEASUREMENTS: Sequential sample of 166 adolescents (aged 12 to 20 years, mean = 15.9 years) enrolled in the clinic. The population was 75% female; the racial-ethnic distribution of the sample was 37.9% black, 29.8% white, 11.2% Asian, 14.3% Hispanic, and 6.8% "other" background. Subjects' social class was primarily lower-middle (60.5%) and middle class (28.6%). A subsample was randomly assigned to be interviewed about their beliefs concerning their follow-up appointment and the constructs of the Health Belief Model. RESULTS: Forty-eight percent of the total sample failed to keep their follow-up appointment. There was a significant positive correlation between social class and appointment keeping (F = 5.07; df = 5,110; P = .026). Neither race-ethnicity nor who made the appointment were found to be associated with follow-up appointment-keeping. The only construct of the Health Belief Model found to be significantly associated with appointment keeping was the number of potential negative outcomes resulting from noncompliance perceived by the subject (F = 6.85; df = 1.74; P = .011). CONCLUSIONS: Clinicians must work with adolescents to improve their understanding of the potential negative outcomes associated with noncompliance to improve appointment-keeping behavior.

Adolescent health insurance coverage: recent changes and access to care.

OBJECTIVE: To assess the health insurance status of adolescents, the trends in adolescent health care coverage, the demographic and socioeconomic correlates of insurance coverage, and the role that insurance coverage plays in influencing access to and use of health care. Together, the results provide a current and comprehensive profile of adolescent health insurance coverage. METHODS: We analyzed data on 14 252 adolescents, ages 10 to 18 years, included in the 1995 National Health Interview Survey. The survey obtained information on insurance coverage and several measures of access and utilization, including usual source of care, site of the usual source of care, indications of missed or delayed care, and use of ambulatory physician services by adolescents. We conducted multivariate analyses to assess the independent association of age, sex, race, poverty status, family structure, family size, region of residence, metropolitan resident status, and health status on the likelihood of insurance coverage. We conducted bivariate and multivariate analyses to ascertain how insurance coverage was related to each of the access and utilization measures obtained in the survey. We also examined trends in health insurance coverage using the 1984, 1989, and 1995 editions of the National Health Interview Survey. RESULTS: An estimated 14.1% of adolescents were uninsured in 1995. Risk of being uninsured was higher for older adolescents, minorities, adolescents in low-income families, and adolescents in single parent households. Compared with their insured counterparts, uninsured adolescents were five times as likely to lack a usual source of care, four times as likely to have unmet health needs, and twice as likely to go without a physician contact during the course of a year. Between 1984 and 1995 the percentage of adolescents with some form of health insurance coverage remained essentially unchanged. During this period, the prevalence of private health insurance decreased, while the prevalence of public health insurance increased. CONCLUSIONS: This study demonstrates the critical importance of health insurance as a determinant of access to and use of health services among adolescents. It also shows that little progress has been made during the past 15 years in reducing the size of the uninsured adolescent population. The new State Children's Health Insurance Program could lead to substantial improvements in access to care for adolescents, but only if states implement effective outreach and enrollment strategies for uninsured adolescents.adolescents, health insurance, access, Medicaid, SCHIP.

Health-risk behaviors and health concerns among young adolescents.

This study examined the health concerns and behaviors of 563 adolescents (aged 11 through 14) from a variety of social, racial, and ethnic backgrounds. Behaviors associated with adolescent morbidity and mortality were examined, including sexual behavior, substance use, and injury-related behaviors. Although young adolescents are often viewed as unlikely participants in these risk behaviors, the results of this study suggest that greater attention should be paid to this younger group and their health-risk behaviors. A majority of the sample had tried alcohol and tobacco, and almost a third had used marijuana. Twenty-one percent were sexually active. Prevalence rates varied by social class, race-ethnicity, gender, and age. More than 75% of the sample had visited a physician during the prior year, suggesting an important role physicians may serve as sources of information and positive role models for these young adolescents. The results suggest that we stop viewing young adolescents as naive children and begin to view them as observers of and participants in a changing social environment that has important implications for their current and future health status. Without a realistic appraisal of the young adolescent, we can expect to have little overall effect on the status of adolescent health in the United States.

Life events, cardiovascular reactivity, and risk behavior in adolescent boys.

BACKGROUND: Risk behavior contributes to injuries, one of the most important sources of morbidity and mortality in adolescents. Although research has shown that environmental stress makes adolescents more likely to engage in risk behavior and to sustain injuries, the magnitude of these associations has been small. Little is known about the role of individual differences in psychobiologic reactivity to stress in moderating the impact of stressful events. In this study, we examined associations among environmental stressors, cardiovascular reactivity to stress, and the level of risk behavior in adolescent boys. METHODS: Twenty-four 14- to 16-year-old boys underwent a laboratory protocol designed to measure responses to psychologically and physically stressful tasks. Changes in heart rate and mean arterial blood pressure were measured serially at standard points in the protocol, and levels of positive and negative life events and recent risk behavior were measured using self-report questionnaires. RESULTS: Neither life events nor cardiovascular reactivity were independently associated with risk behavior. Positive life events and mean arterial blood pressure reactivity significantly interacted, however, in predicting risk behavior (R2 increment = .25). Boys with high reactivity who reported numerous positive life events engaged in markedly less risk behavior than their peers. CONCLUSION: We conclude that adolescents with exaggerated cardiovascular responses to laboratory stressors are associated with less risk behavior in a setting of positive life circumstances. This result suggests that reactivity may exert protective, rather than harmful, influences in some environments.

How far have state Medicaid agencies advanced in performance measurement for children?

BACKGROUND: While children represent the largest population group enrolled in Medicaid managed care, little is known about the pediatric performance measures used by state Medicaid agencies. OBJECTIVE: To identify Medicaid managed care requirements for using Health Plan Employer Data and Information Set and other performance measures for children (defined as those aged 0-21 years in this study). DESIGN: A structured telephone survey of pediatric performance measures. PARTICIPANTS: Survey respondents were state Medicaid officials responsible for managed care quality oversight in 39 states. MAIN OUTCOME MEASURES: Percentage of states in 1998 with effectiveness-of-care measures on health promotion and disease prevention, early detection and screening, and acute and chronic illness; with use measures on preventive care, ambulatory care, pharmacy, inpatient hospital care, and mental health and chemical dependency services; and with access measures on primary care, low-birth-weight neonates delivered at appropriate facilities, and dental care. RESULTS: In 1998, state Medicaid agencies placed most of their emphasis on monitoring preventive care for children, with immunization rates being the primary focus. Far less attention was directed at assessing the treatment of acute illness. Although more than half of states monitored the treatment of chronic childhood conditions, they focused exclusively on asthma and selected mental health diagnoses. CONCLUSIONS: States are still in the initial phases of designing and implementing quality oversight systems for Medicaid-insured children. Additional quality reporting requirements are clearly needed to assess the treatment of acute and chronic illness among children along with more age-specific reporting requirements.

Preventive services in a health maintenance organization: how well do pediatricians screen and educate adolescent patients?

OBJECTIVE: To determine whether pediatricians in managed care settings adhere to national guidelines concerning the provision of clinical preventive services. DESIGN: Surveys were mailed between September 1996 and April 1997 to all pediatricians practicing in a California group-model health maintenance organization. The survey asked pediatricians about their screening and education practices on 34 recommended services and the actions taken with adolescent patients who have engaged in risk behavior. RESULTS: The response rate was 66.2% (N = 366). Pediatricians, on average, screened 92% of their adolescent patients for immunization status and blood pressure; 85% for school performance; 60% to 80% for obesity, sexual intercourse, cigarette use, alcohol use, drug use, and seat belt and helmet use; 30% to 47% for access to handguns, suicide, eating disorders, depression, and driving after drinking alcohol; fewer than 20% for use of smokeless tobacco, sexual orientation, sexual and physical abuse, and riding a bike or swimming after drinking alcohol; and 26% to 41% for close friends' engagement in risk behavior. Pediatricians' assessment and education with adolescent patients who screened positive for risk behavior was particularly low. Female physicians, physicians who saw a greater proportion of older adolescents, and recent medical school graduates were more likely to provide preventive services. CONCLUSIONS: Pediatricians in this health maintenance organization provide preventive services to adolescent patients at rates below recommendations but at rates greater than physicians in other practice settings. Improvement is especially needed in the areas that contribute most to adolescent mortality and for patients who screen positive for a risk behavior.

Self-concept in the diethylstilbestrol daughter.

To evaluate the possible psychologic impact of diethylstilbestrol (DES) in utero exposure on young women, the authors studied self-concept as a multifaceted construct in 25 known DES in utero exposed young women compared with 25 age-matched controls. Psychologic inventories used included Rosenberg's Self-Esteem Scale, Adjective Check List, Who Am I Test, Wyeth 's Self-Satisfaction Ladder, and the Draw Yourself Test, as well as semi-structured personal interview. Diethylstilbestrol subjects differed significantly from controls on the adjective check list subscales of Defensiveness, Nurturance, and Affiliation (P less than or equal to .05), as well as in the Draw Yourself Test, by omitting or obscuring body parts, especially sexual characteristics (P = .001). Subjects with known physical sequelae associated with DES were less satisfied with their lives (P = .05). On other measures of self-concept, no peer differences between DES subjects and controls were found. In fact, a trend for DES subjects to describe themselves more positively emerged. Most women also mentioned that they trusted physicians and were concerned about their future fertility and about the possibility of developing cancer. These findings suggest that young women exposed to DES may be using protective denial in their attempt to cope with their DES exposure. Physicians need to be aware of the possible psychologic impact of DES exposure, especially as more data become available regarding decreased fertility in these women and as new attention is focused on young men exposed to DES in utero.

Concepts of health and illness: different constructs or variations on a theme?

Although health and illness concepts are thought to be important mediators of health and illness behaviors, little work has been done examining health concepts, and no research has examined the two conceptual structures simultaneously. This study examined concepts of health and illness in 218 adolescents between the ages of 11 and 18 years. Results were consistent with the hypothesis that concepts of health and illness are not opposite ends of a single health dimension, but reflect different and overlapping constructs. The degree of overlap varied as a function of age, with health concepts showing less emphasis on "the absence of illness" with greater maturity. The results suggest that models of health behavior that focus on illness avoidance neglect many components of health salient to lay persons.

Autonomy, relatedness, and the initiation of health risk behaviors in early adolescence.

This study examined the relationships among sociodemographic characteristics, family processes, and the initiation of health risk behaviors in early adolescence. Subjects were 189 6th and 7th graders from a public middle school. A path-analytic model was used to analyze data. Results showed that students who received autonomy support from parents were less likely to initiate sexual intercourse. Students who were emotionally detached from their parents were more likely to fight and use substances. Those who were emotionally detached tended to come from families with low levels of cohesion and acceptance. Sociodemographic variables, such as family structure, gender, and ethnicity, had both direct and indirect effects on health risk behaviors, but the indirect effects were quite small.

Initiation of substance use in early adolescence: the roles of pubertal timing and emotional distress.

Two hypotheses regarding the effects of pubertal timing on substance use were tested in a prospective study of 221 young adolescents. A maturational-deviance hypothesis predicted that early-maturing girls and late-maturing boys would experience heightened emotional distress, which in turn would influence initiation and use of substances. Alternatively, an early-maturation hypothesis predicted that early-maturing girls would engage in more substance use than all other groups, independent of emotional distress. Early-maturing adolescents reported more substance use within 1 year. Adolescents experiencing elevated levels of negative affect also reported greater substance use within the next year. However, pubertal timing was not related to emotional distress. Results support the early-maturation hypothesis for girls and suggest its extension to boys.

Adolescent obesity intervention: validation of the SHAPEDOWN program.

The effectiveness of the adolescent obesity intervention SHAPEDOWN was evaluated for 15 months through a randomized experimental design study. Test groups (no. = 37) participating in the intervention were compared with a no-treatment control group (no. = 29) at four sites in northern California. The program employs a variety of cognitive, behavioral, and affective techniques adapted to make successive small modifications in diet, exercise, communication, and affect that are sustainable. Very-low-calorie or restrictive diets are avoided in the program. Parents are instructed on strategies for supporting their adolescents' weight-loss efforts. Participation in the group application of the program was associated with significant improvement in relative weight, weight-related behavior, depression, and knowledge of weight management concepts at post-treatment and at 1-year follow-up. Self-esteem increased significantly regardless of condition. Change in relative weight for the test group was -9.9 +/- 14.9% (mean +/- standard deviation) and for the control group was -0.10 +/- 13.2%. At month 15 of the study period, weight change in the test group compared with the controls was -5.15 kg. For all subject variables examined in the test group, mean change in relative weight at 1-year follow-up was negative, suggesting that none of the characteristics examined contraindicate program participation among obese adolescents seeking care. Drop-out rate was 16%. The study suggests that the program produces significant long-term outcomes in obese adolescents and is transferable to a variety of settings.

Validity of self-report of pubertal maturation in early adolescents.

Self-report measures of sexual maturation continue to be used to classify pubertal development even though their reliability remains in question. This study examined the accuracy of self-report measures by early adolescents in two settings. Standardized figured drawings depicting Tanner's sexual maturation scale (SMS) were shown to early adolescents at school (S1) and again in a clinical sitting (S2), and subjects were asked to rate their own pubertal development. Physical examination by a physician at S2 was used to corroborate sexual maturation. Participating in the study were 46 males, age 11-14 years (mean, 12.4, SD, 1.9), and 37 females, age 11-14 years (mean, 12.7, SD, 0.7). Concordance rate between physical examination and self-report of pubic hair development (males) at S1 was 58% (kappa = 0.35, p less than 0.0001) and 78% (kappa = .66, p less than 0.0001) at S2. Concordance rate of self-report of genital development at S1 and S2 was 27% (kappa = -0.06, p less than 0.49) and 44% (kappa = 0.18, p less than 0.04), respectively. Self-report of breast development demonstrated a concordance rate of 59% (kappa = 0.43, p less than 0.0001) at S1 and 72% (kappa = 0.59, p less than 0.0001) at S2. Concordance rate for self-report of pubic hair development in females was 58% at S1 (kappa = 0.42, p less than 0.0001) and 75% at S2 (kappa = 0.64, p less than 0.0001). There was a tendency for subjects to overestimate their development at early stages of maturation and underestimate development at later stages.(ABSTRACT TRUNCATED AT 250 WORDS)

Early adolescent knowledge and attitudes about circumcision: methods and implications for research.

The psychosocial effects of circumcision status on the adolescent male are unclear. This study explored methods for assessing attitudes toward circumcision of early adolescents and differences in satisfaction between circumcised and uncircumcised males that would warrant further investigation. Seventy-three boys, aged 11 through 14 years completed the Petersen Body Image Scale and a questionnaire concerning their own circumcision status, satisfaction with that status, and perceptions about the status of other family members and peers. To assess knowledge, subjects identified diagrams depicting differing circumcision states during a personal interview. Physical examination confirmed reported circumcision status. Of the study group, 19% (n = 14) were uncircumcised. Use of visual aids to report circumcision status was more accurate (92%) than self-report (68%). Circumcised boys scored higher on satisfaction items than did uncircumcised boys, (t(15.65) = -3.96, p less than 0.001). No differences in general body image were found between groups. Further research that examines psychosocial outcomes of circumcision status is necessary.

Primary care physicians' screening of adolescent patients: a survey of California physicians.

PURPOSE: To determine how often primary care physicians screen adolescents for important risk factors and to determine how rates of screening vary by physicians' specialty and practice setting, patients' age, and type of risk factor. METHODS: A stratified random sample of 343 California physicians who are Board certified in pediatrics, family practice, or internal medicine, and physicians in these specialties who specialized in adolescent medicine were surveyed about their screening practices using a mailed questionnaire. Subjects were asked the percentage of routine comprehensive physical examination during which they personally queried or screened each age group of adolescents (11-14 years old and 15-18 years old) for each of the following risk factors: high blood pressure, alcohol use, cigarette use, sexual activity, and drug use. RESULTS: The frequency with which primary care physicians reported actually screening younger and older adolescents for the various risks were approximately: 93% and 96% for high blood pressure, 70% and 84% for alcohol use, 74% and 82% for drug use, 67% and 83% for sexual activity, and 76% and 86% for smoking, respectively. For all risk factors, providers screened older adolescents more frequently than younger adolescents (p < 0.01). Finally, screening rates varied by specialty (p < 0.01) but not by practice setting. CONCLUSIONS: This study found that California physicians frequently screen adolescents for a variety of risk factors. However, the reported rates may not be consistent with published guidelines. Interventions may need to be developed which focus on improving primary care physicians' adolescent-specific screening practices.

Puberty questions asked by early adolescents: what do they want to know?

OBJECTIVE: We undertook the following study to document questions asked by early adolescents regarding pubertal development. METHODS: As part of a health education program, 159 sixth-grade students (mean = 12.1 years) were surveyed to obtain their questions about puberty and their self-assessed pubertal stage. Questions were coded for content and gender specificity. RESULTS: Of 159 initial subjects, 111 generated a total of 200 questions. A majority of the questions reflected biological topics (88%), such as genital physiology (26%) and sexuality and reproduction (26%). Only 6% addressed psychosocial questions. Both females and Asians (compared with other ethnic or racial groups) expressed greater interest in the differences between male and female development (P < .05). Prepubertal males were more concerned about general puberty than were boys in later Tanner stages (P < .05). Earlier maturing males focused on genital anatomy (P < .05). CONCLUSIONS: We found that biological questions concerning puberty predominated over psychosocial topics, and that the gender, race or ethnicity, and stage of development determined the kinds of questions that early adolescents have about pubertal development. Health educators and clinicians may need to focus on physiologic areas to provide more meaningful information about development to early adolescents.

Utilization of ambulatory health services by urban adolescents.

PURPOSE: To describe adolescents' utilization of ambulatory health services and its association with sociodemographic and health status characteristics. METHODS: Adolescents (N = 199) were selected from a larger group of urban middle and high school students who had previously participated in a health risk survey. Subjects were surveyed about their health status and use of ambulatory medical services. Subjects' parents/guardians were also surveyed about sociodemographic information. Bivariate and multivariate analyses using Chisquare statistics and logistic regression techniques assessed the contribution of hypothesized variables to use of routine medical, illness-related medical, and dental services. RESULTS: Most adolescents reported having seen a physician (70%) or a dentist (79%) within the past year. Subjects reported using a wide variety of practitioners and settings, with family/general practitioners (29%), and the private office setting (23%) most commonly reported. Subjects having a regular source of care and those perceiving their health as "excellent" or "very good" were 2.4 and 3.4 times more likely to have used routine medical services than those without a regular source of care and those reporting their health as "fair" or "poor." In contrast, the strongest predictors of having received illness-related care in the past year were the presence of a current medical problem and an age by gender interaction factor. Those reporting a current medical problem were twice as likely as those not reporting a problem and older females were 6.6 times as likely as younger males to have received illness-related care within the past year. The only significant predictor of recent dental care was having private insurance. CONCLUSION: For adolescents enabling variables, such as having a regular source of care and health insurance, are stronger predictors of routine use of medical and dental care, whereas medical need and sociodemographic factors, such as age and gender, are more important in predicting use of illness-related care. These results support, in part, models that have been previously developed to explain use of ambulatory health services.

The state of adolescent health: looking back and planning ahead.

PURPOSE: A decade has passed since the 1986 Health Futures of Youth policy-making conference was held. The present study aimed to examine perceived changes in the field of adolescent health since this conference, as a basis for further planning in adolescent health and consideration of a possible follow-up conference. METHODS: The study included two parts: (a) a mailed survey which was completed by 68 of 90 conference participants; and (b) telephone interviews with a sample of leaders from federal agencies and major foundations and one professional organization serving youth in the United States. RESULTS: Respondents perceived that small to moderate improvements have occurred for 10 key recommendations made at the 1986 conference. There appears to be increased recognition of the special needs of youth and a greater understanding of the period of adolescence. Improvements in health-related activities and in research of health behaviors have occurred. However, perceived setbacks have occurred at the intersection of health and social welfare. The conference was viewed by respondents as having had a moderate influence on the field of adolescent health and on the participants' own work and working relationships. In addition, policy-making conferences were listed as the strongest source of influence on the agenda of national agencies and foundations serving youth. CONCLUSION: A follow-up conference is recommended and should focus on both health-related topics and issues of social welfare.