Effects of physical activity on exercise tests and respiratory function

BACKGROUND

Exercise is an important component of pulmonary rehabilitation for patients with chronic lung disease.

OBJECTIVE

To explore the role of physical activity in maintaining cardiac and respiratory function in healthy people.

METHODS

Cardiorespiratory fitness was measured by a maximal treadmill test (MTT), and respiratory function was tested by spirometry. The cross sectional study included data from 24 536 healthy persons who were examined at the Cooper Clinic between 1971 and 1995; the longitudinal study included data from 5707 healthy persons who had an initial visit between 1971 and 1995 and a subsequent visit during the next five years. All participants were aged 25-55 years and completed a cardiorespiratory test and a medical questionnaire.

RESULTS

In the cross sectional study, after controlling for covariates, being active and not being a recent smoker were associated with better cardiorespiratory fitness and respiratory function in both men and women. In the follow up study, persons who remained or became active had better MTT than persons who remained or became sedentary. Men who remained active had higher forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC) than the other groups. Smoking was related to lower cardiorespiratory fitness and respiratory function.

CONCLUSIONS

Physical activity and non-smoking or smoking cessation is associated with maintenance of cardiorespiratory fitness. Change in physical activity habits is associated with change in cardiorespiratory fitness, but respiratory function contributed little to this association during a five year follow up.

Omission of active commuting to school and the prevalence of children's health-related physical activity levels: the Russian Longitudinal Monitoring Study

BACKGROUND

Active commuting to school by walking or bicycle is a potential source of continuous moderate activity for children that has been largely ignored in surveys of physical activity. The purpose of this study was to evaluate the analytical impact of omitting active commuting to school (walking or bicycling) on conclusions about children's physical activity levels.

METHODS

The Russian Longitudinal Monitoring Study (RLMS) is the first nationally representative household survey in the Russian Federation. More than 6400 households from all regions of Russia were surveyed eight times between 1992 and 1998. Analysis was conducted using physical activity data (school physical education classes, out-of-school active pursuits and active commuting to school) obtained by parent-proxy on 1094 (572 boys, 522 girls) school-aged Russian children (mean age 10.2 +/- 1.9 years) participating in the November 1998 round of the RLMS. Data were examined according to prevalence of achievement of health-related physical activity guidelines, active commuting to school behaviours included then omitted.

RESULTS

Omitting active commuting to school resulted in a statistically significant decrease in the prevalence of achievement of health-related guidelines from 12% to 20%, similar for both genders. Likewise, the prevalence of sedentarism (defined as not meeting any of the guidelines) was increased by 17-22%.

CONCLUSIONS

The present findings suggest that, in order to avoid misclassification bias of children's physical activity levels, it is necessary to include questions about mode of commuting to school. The findings also carry practice implications: the commonplace need to get to and from school may be a missed opportunity for children's health-related physical activity in motorized societies.

Factors influencing intent to get pregnant in HIV-infected women living in the southern USA

This descriptive study sought to identify factors that influence HIV-infected women's intent to get pregnant. Interviews were conducted with a convenience sample of n = 322 HIV-infected women at risk for pregnancy. Participants were predominantly African-American (84.4%), single (57.9%), and ranged in age from 17 to 48 years. Forty per cent (n = 128) of the women had been pregnant since becoming HIV-positive. Potential factors influencing intent to get pregnant that were examined included demographic characteristics, HIV-related factors and personal beliefs and attitudes. In simple logistic regression models, younger age, increased motivation for child bearing, decreased perceived threat of HIV, decreased HIV symptomatology, higher traditional gender role orientation, and greater avoidance coping were all associated with greater intent to get pregnant. Following a model selection procedure, motivation for child bearing (OR = 16.05, 95% CI 7.95, 30.41) and traditional sex roles (OR = 4.49, 95% CI 1.44, 13.55) were significantly associated with greater intent to get pregnant. Traditional gender role orientation and motivation for childbearing are significant factors in predicting intent to get pregnant among HIV-infected women. These factors, as well as other non HIV-related factors, need to be routinely assessed by health care providers in developing plans of care for HIV-infected women.

Behavioral and demographic correlates of diabetes, hypertension and overweight among the Catawba Indian Nation

OBJECTIVE

In 1998, the Catawba Diabetes and Health Survey (CDHS) was conducted among adult members of the Catawba Indian Nation living in the Carolinas to determine the prevalence of diabetes and other health conditions, and to assess the population's health-related behaviors.

DESIGN

A population-based sample of adult members of the Catawba Indian Nation (N = 633) were surveyed by telephone or in person regarding health status and health-related behaviors. Logistic regression was used to determine demographic and behavioral correlates of diabetes, hypertension, and overweight among the Catawba.

RESULTS

Age-adjusted prevalence rates of self-reported diabetes, hypertension and overweight were 12.3%, 29.1%, and 63.8%, respectively. Older age was related to diabetes, hypertension, and overweight (P<.0001 each), and heavier weight status was related to diabetes (P = .026) and hypertension (P<.0001). Nearly 40% of the Catawba are physically inactive (29.5% men, 46.5% women). Physical inactivity was related to diabetes and hypertension among men only, and related to overweight among women only (P<.05 each). Current smoking was inversely related to overweight among men and women (P = .002). Dietary behavior was not associated with the health outcomes.

CONCLUSION

Given the high rates of overweight and physical inactivity, reducing the rates of both may be very important for the health of the Catawba, considering their association with diabetes and hypertension.

The relationship between pedometer-determined ambulatory activity and body composition variables

OBJECTIVE

To examine the relationship between pedometer-determined ambulatory activity (steps/day) and body composition variables body mass index (BMI) and percentage body fat).

DESIGN

: Secondary analysis of a cross-sectional objective activity monitoring study for up to 21 consecutive days.

SUBJECTS

A total of 109 apparently healthy adults (eight African American males, 23 African-American females, 33 Caucasian males, 45 Caucasian females), age 44.9+/-15.8 y, BMI=26.9+/-5.1 kg/m2.

MEASUREMENTS

Pedometer-assessed ambulatory activity (steps/day), height and weight, and percentage body fat by bioelectrical impedance.

RESULTS

Analyzed as both a continuous and a categorical variable (determined using 25th and 75th percentiles for distribution for steps/day), ambulatory activity was consistently related to body composition variables. Steps/day was inversely correlated with BMI and percentage body fat (r=-0.30, and r=-0.27, respectively, both P<0.01). The consistency of the relationship was also evident when examined using accepted BMI cut-off points for normal-weight, overweight, and obese categories.

CONCLUSIONS

Individuals in this small sample with values greater than approximately 9000 steps/day are more frequently classified as normal weight for height. Individuals with values less than approximately 5000 steps/day are more frequently classified as obese. These findings require further corroborative investigation but provide preliminary cutoff points for identifying individuals at risk who may benefit from appropriate physical activity intervention.

Prevalence of attention-deficit/hyperactivity disorder in a community sample of older adolescents

OBJECTIVE

To study the prevalence and correlates of attention-deficit/hyperactivity disorder (ADHD) in a community sample of older adolescents.

METHOD

From 1986 to 1988, 3,419 seventh, eighth, and ninth graders were screened with the Center for Epidemiologic Studies-Depression Scale. The top decile scorers and a random sample of the remainder were interviewed with the Schedule for Affective Disorders and Schizophrenia for School-Age Children. These data are from the second wave of interviews (N = 490, mean age = 18.65).

RESULTS

The weighted prevalence of DSM-III-R ADHD was 1.51% (males: 2.62%, females: 0.54%). Significant associations (p < .05) were found for gender (male), comorbid affective disorders, baseline undesirable life events, and fewer than two biological parents at baseline. Family cohesion (p = .058) is inversely associated with ADHD. For subjects not meeting the age-at-onset criterion, 1.94% met the eight symptom criteria, and females (3.2%) were more prevalent than males (0.3%).

CONCLUSIONS

ADHD remains a problem in this sample of older adolescents and is often comorbid with affective disorders. A significant number report eight ADHD symptoms but do not meet the age-at-onset criterion. This group deserves research attention.

Association among physical activity level, cardiorespiratory fitness, and risk of musculoskeletal injury

To help public health practitioners promote physical activities with a low risk of injury, this study determined the relation among type and duration of physical activity, cardiorespiratory fitness, and musculoskeletal injury in a sample of adults enrolled in the Aerobics Center Longitudinal Study. Subjects included 4,034 men and 967 women who underwent a baseline physical examination between 1970 and 1985 and who returned a mailed follow-up survey in 1986. At baseline, a treadmill graded exercise test was used to measure cardiorespiratory fitness. At follow-up, subjects reported injuries and type and duration of physical activity in the preceding 12 months. Polytomous logistic regression was used to estimate the association among physical activity type and duration, cardiorespiratory fitness, and injury. The risk of sustaining an activity-related injury increased with higher duration of physical activity per week and cardiorespiratory fitness levels. Results suggest that cardiorespiratory fitness may be a surrogate for unmeasured components of physical activity, such as exercise intensity. Among walkers, increasing duration of activity per week was not associated with an increased risk of injury. Results suggest that, for most adults, walking is a safe form of physical activity associated with a lower risk of injury than running or sport participation.

Racial/ethnic health disparities in South Carolina and the role of rural locality and educational attainment

BACKGROUND

The prevalence of selected health indicators were compared among the Catawba Indians, African Americans, and whites in South Carolina, considering the possible role of rural locality and education.

METHODS

Catawba members were respondents of a 1998 survey (N = 808). Other South Carolina residents were respondents of the 1995-1997 Behavioral Risk Factor Survey (4,150 whites and 1,413 African Americans). Prevalence of cardiovascular disease, diabetes, hypertension, overweight, poor health, smoking, physical inactivity, and poor diet were compared among the racial/ethnic groups. Logistic regression analyses were conducted within strata of urban/rural locality and education to determine whether these factors were associated with the adverse health indicators.

RESULTS

Both Catawba and African Americans had higher prevalence of diabetes, hypertension, overweight, poor health, physical inactivity, and poor diet than whites. In addition, prevalence of diabetes, poor health, smoking, and poor diet were higher among the Catawba than among African Americans. Restricting the analyses to comparisons within urban/rural locality had little effect, whereas restricting the analyses to comparisons by education level eliminated many of the disparities among those with low education.

CONCLUSIONS

Prevalence of chronic disease and adverse health behavior are higher among the Catawba than among other residents of South Carolina, especially compared with white residents.

Insulin resistance precedes weight loss in adults without diabetes : the Rancho Bernardo Study

Insulin resistance is closely associated with both aging and overweight; yet in old age, weight loss is common, although insulin resistance increases. To study this paradox, the authors evaluated the role of insulin resistance in weight change among older adults from the Rancho Bernardo Study cohort. Participants were 725 nondiabetic men and women who were aged 50-89 years when weight and insulin were measured at baseline (1984-1987). The participants were evaluated again in 1992-1996, at which time weight was remeasured. Fasting insulin and homeostasis model assessment (HOMA) measurements were evaluated in separate but parallel statistical models as surrogates for insulin resistance. Insulin resistance, when defined as the top quartile of fasting insulin level or HOMA value, was significantly associated with weight loss before and after adjustment for baseline weight and age (fasting insulin: beta = -1.30 kg, p = 0.01; HOMA: beta = -1.18 kg, p = 0.01). Results were the same for men versus women, for the overweight (body mass index (weight (kg)/height (m)(2)) > 26.6) [corrected] versus the normal weight (body mass index < or = 26.6) [corrected], and for younger persons (age <70 years) versus older persons (age > or = 70 years). Insulin-resistant individuals had a threefold increased likelihood of losing 10 or more kg compared with those without insulin resistance. The authors conclude that hyperinsulinemia, independently of age and baseline weight, may have a catabolic effect in the elderly.

Environmental influences, physical activity, and weight status in 8- to 16-year-olds

OBJECTIVE

To assess the association between vigorous physical activity, participation on sport teams and in exercise programs, television watching, family environment, and weight status in youth.

DESIGN

Cross-sectional data from the Third National Health and Nutrition Examination Survey.

PARTICIPANTS

A group of 2791 youth between the ages of 8 and 16 years who were enrolled in the Third National Health and Nutrition Examination Survey.

MAIN OUTCOME MEASURES

Overweight was defined using age- and sex-specific 85th percentile of body mass index using Center for Disease Control and Prevention growth charts.

RESULTS

Both males and females who had an overweight mother and or father were more likely to be overweight compared with youth who did not have an overweight parent. Females who watched 4 or more hours of television were more likely to be overweight than those who watched less than 4 hours. Males and 14- to 16-year-old females who participated in sport team and exercise programs were less likely to be overweight than their counterparts who did not participate. Also, females with larger families and males from families with higher family incomes were less likely to be overweight.

CONCLUSIONS

These results suggest that family environment is associated with overweight in youth and that sport and exercise program participants are less like to be overweight and that, for females, increased television watching is related to overweight.

Physical activity, physical fitness, and Framingham 10-year risk score: the cross-cultural activity participation study

PURPOSE

Although physical activity and physical fitness are inversely and causally associated with coronary heart disease (CHD) morbidity and mortality, available equations for estimating CHD risk do not include scores for activity or fitness. Therefore, this study evaluated the association of physical fitness and moderate-intensity physical activity with the 10-year Framingham CHD risk estimate.

METHODS

Cross-sectional analyses were performed on data from 137 healthy middle-aged women (53.9 +/- 9.9 yr; 28.3 +/- 6.0 kg/m2). Health histories, body composition, blood pressure, and blood samples were obtained from a clinical examination. Levels of moderate (3-6 METS) intensity physical activity, expressed as MET-minutes/day of energy expenditure, were derived from multiple 24-hour physical activity records. Physical fitness was quantified as duration of a symptom-limited maximal treadmill exercise test.

RESULTS

After adjustment for race, body mass index (BMI), and hormone replacement status, a graded reduction in the Framingham risk score was observed across low (5.8%), moderate (4.0%), and high (3.6%) fitness levels (P for trend = 0.009). Women in both the moderate and high fitness categories had a lower (P < 0.01) risk score compared with their low fit counterparts. Significant differences in risk were not seen among low (3.9%), moderate (4.9%), and high (4.4%) physical activity groups. The lack of association between the risk score by physical activity may have been due to the homogeneity of activity levels among participants. Our findings reinforce existing data that show enhanced levels of fitness are associated with lower risk for CHD.

A longitudinal study of adolescent mental health service use

This study examines longitudinal mental health service use patterns of a school-based sample of adolescents. Based on the Center for Epidemiologic Studies Depression Scale scores, a stratified sample of middle-school students was interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Aged Children: cycle one (n = 579; mean age 12.83) and cycle two (n = 490; mean age 18.65). Service use also was assessed by mailed questionnaire: cycle three (n = 330; mean age 20.60). Service use decreased over time. Whites and males received significantly more treatment in the first cycle. In the second cycle, service use by race and gender was equal; in the third cycle, females received more treatment. Those with a psychiatric diagnosis (first cycle, 54%; second cycle, 33%) received treatment in the prior year. Under-treatment of youth with psychiatric diagnoses is a significant problem, with differences in service use by race and gender over time.

Moderate-intensity physical activity and fasting insulin levels in women: the Cross-Cultural Activity Participation Study

OBJECTIVE

The purpose of this study was to determine the association between moderate-intensity physical activity (PA) and fasting insulin levels among African-American (n = 47), Native American (n = 46), and Caucasian women (n = 49), aged 40-83 years, enrolled in the Cross-Cultural Activity Participation Study. Associations by race/ethnicity, levels of central obesity, and cardiorespiratory fitness were also examined.

RESEARCH DESIGN AND METHODS

Physical activity scores were obtained from detailed PA records that included all PA performed during two consecutive 4-day periods scheduled 1 month apart. Using MET intensity (the associated metabolic rate for a specific activity divided by a standard resting metabolic rate), PA was expressed as MET-min (the product of the minutes for each activity times the MET intensity level) per day of energy expended in moderate (3-6 METs) and moderate/vigorous (> or = 3 METs) PA. Fasting insulin levels were determined by radioimmunoassay. Data were analyzed by multiple linear regression analysis.

RESULTS

After adjusting for race/ethnicity, age, educational attainment, and site, an increase of 30 min of moderate-intensity PA was associated with a 6.6% lower fasting insulin level (P < 0.05). The association was similar among races/ethnicities, centrally lean and centrally obese women, and women with low and high cardiorespiratory fitness levels.

CONCLUSIONS

These findings lend support to the 1995 Centers for Disease Control and Prevention and American College of Sports Medicine recommendations for an accumulation of 30 min/day in moderate-intensity PA. They also contribute to the growing literature suggesting that moderate amounts of PA have a significant role in reducing the burden of hyperinsulinemia and diabetes among ethnic populations at highest risk for these conditions.

Association of very low birth weight with exposures to environmental sulfur dioxide and total suspended particulates

This paper presents results of a population-based case-control study of the association between maternal exposures to environmental sulfur dioxide and total suspended particulates (TSP) and risk for having a very low birth weight (VLBW) baby, i.e., one weighing less than 1,500 g at birth. The study, which took place between April 1, 1986 and March 30, 1988, comprised 143 mothers of VLBW babies and 202 mothers of babies weighing 2,500 g or more living in Georgia Health Care District 9. Environmental exposure estimates (microg/m3) were obtained through environmental transport modeling that allowed us to assign environmental sulfur dioxide and TSP exposure estimates at the birth home of each study subject. Exposures less than or equal to 9.94 microg/m3, the median of TSP and sulfur dioxide exposures for the controls, were considered as referent exposures. Exposures to atmospheric TSP and sulfur dioxide above the 95th percentile (56.75 microg/m3) yielded an adjusted odds ratio of 2.88 (95% confidence interval (CI): 1.16, 7.13), that from above the 75th to the 95th percentile (25.18-56.75 microg/m3) yielded an adjusted odds ratio of 1.27 (95% CI: 0.68, 2.37), and that from above the median (9.94 microg/m3) to the 75th percentile, an adjusted odds ratio of 0.99 (95% CI: 0.51, 1.72). The trend demonstrated in these adjusted estimates suggests an association between VLBW and maternal exposures to high levels of air pollution.

Estimating environmental exposures to sulfur dioxide from multiple industrial sources for a case-control study

This paper first discusses how population exposures to environmental pollutants are estimated from environmental monitoring data and the problems that are encountered in estimating risk from pollutants on the basis of ecologic studies. We then present a technique of estimating individualized exposures to an atmospheric pollutant, sulfur dioxide (SO2), through atmospheric transport modeling for a case-control study. The transport model uses the quantities of SO2 released from 30 geographically identified industrial facilities and meteorological data (wind speed and direction) to predict the downwind ground-level concentrations of SO2 at geographically identified residences, receptors, of 797 study subjects. A distribution of facility SO2 emissions, uncertainties in effective stack height, and model uncertainty are incorporated to examine the uncertainty in the predicted versus ambient monitoring SO2 levels, and to generate an exposure uncertainty distribution for both the cases and controls. The transport model's accuracy is evaluated by comparing recorded ambient measurements of SO2 with the model's predicted SO2 estimates at geographically identified ambient monitoring stations.

Moderate physical activity patterns of minority women: the Cross-Cultural Activity Participation Study

Using data from 12 days of detailed physical activity records (PA records), we analyzed the physical activity patterns of 141 African American and Native American women, ages 40 and older, enrolled in the Cross-Cultural Activity Participation Study. PA records were completed every other month for three consecutive 4-day periods. The proportion of women who met the 1993 Centers for Disease Control and Prevention and the American College of Sports Medicine recommendation to accumulate at least 30 minutes of moderate intensity activity during most days of the week (at least 3 days of the 4-day periods) ranged from 63% to 70%. Nearly one third of women met the recommendation for more than one 4-day period. On days when subjects accumulated at least 30 minutes of moderate activity, time spent in moderate activity was 112 minutes/day. Most women performed household chores (95%, median = 24 minutes/day), walking for exercise (87%, median = 30 minutes/day), occupational (65%, median = 37 minutes/day), child care (53%, median = 32 minutes/day), and lawn and garden activities (51%, median = 43 minutes/day). Fewer than 25% reported conditioning and sports activities. In general, more Native Americans than African Americans were active in moderate activities. In conclusion, definitions used to characterize regular physical activity should be consistent among studies, and physical activity surveys among women should include occupation-related and home-related activities.

Incidence and predictors of suicidal behaviors in a longitudinal sample of young adolescents

OBJECTIVE

This analysis examines 1-year transition probabilities and baseline predictors for suicidal behaviors in young adolescents.

METHOD

Adolescents from a two-stage, community-based longitudinal study were classified into suicidal behavior categories (attempt, plan, ideation, and none) for baseline and follow-up years. Transition probabilities for movement among categories were calculated, and polytomous logistic regression analysis was used to examine predictors of suicidal behaviors.

RESULTS

Among those with no suicidal behaviors at baseline, 1-year incidence rates were 1.3% for attempts and 1.7% each for plans and ideation. Increasing family cohesion was protective for suicide attempts (odds ratio [OR] = 0.9). Female subjects were more likely than males to report plans (OR = 8.9) and ideation (OR = 4.1). Increasing impulsivity (OR = 2.3), prior suicidal behavior (OR = 10.6), and undesirable life events (OR = 1.1) were significant predictors of plans.

CONCLUSIONS

While there are a number of predictors of suicidal behaviors, the false-positive rate is high. Focusing on proximal risk factors, particularly stressors in adolescent development, may overlook the fundamental role of underlying mental disorder and familial factors--both biological and environmental. Suicide and suicidal behaviors are the result of a constellation of adverse factors requiring a range of interventions for prevention.

Body fat distribution and race differences in apolipoprotein A1

OBJECTIVE

This is the first study to assess the role of waist-to-hip ratio in explaining race differences in levels of serum apolipoprotein A1, a protective risk factor for atherosclerosis.

METHODS

Linear regression analyses were used in a community-based survey of 3,043 adults (23.5% African-American) to assess associations of race, age, anthropometric measures, education, diabetes, blood pressure medication use, cigarette smoking, and leisure-time physical activity with apolipoprotein A1 levels.

RESULTS

Higher apolipoprotein A1 levels were observed among African-American than among white adults (African-American men: +15.6 mg/dl than white men, African-American women: +3.1 mg/dl more than white women; p < 0.05). Waist-to-hip ratio and other variables did not account for race differences among men. African-American women had +8.6 mg/dl higher levels than white women after adjustment for differing distributions of waist-to-hip ratio, age, body mass index and education. Cigarette smoking, physical activity, and medical history accounted for no further differences among women.

CONCLUSIONS

Higher levels of obesity indicators and lower educational attainment among African-American women reduced a potentially greater beneficial race difference in apolipoprotein A1. These findings also suggest that other environmental and biochemical factors may play roles in explaining the higher protective levels of apolipoprotein A1 observed among African-American children and adults.

Prevalence of PTSD in a community sample of older adolescents

OBJECTIVE

To examine prevalence and correlates of trauma and posttraumatic stress disorder (PTSD) symptoms and diagnosis in older adolescents aged 16 through 22 years.

METHOD

The second cycle of a longitudinal epidemiological study in the Southeast included a semistructured interview assessing PTSD symptomatology administered to 490 adolescents.

RESULTS

Approximately 3% of female subjects and 1% of male subjects satisfied the DSM-IV criteria for PTSD. Females reported more traumatic events than males, and black subjects reported more events than white subjects. Being female (odds ratio = 12.32), experiencing rape or child sexual abuse (odds ratio = 49.37), and witnessing an accident or medical emergency (odds ratio = 85.02) were associated with increased risk of PTSD.

CONCLUSIONS

While relatively few adolescents satisfy the criteria for PTSD, most subjects who experienced a traumatic event reported some PTSD symptoms. Specific types of traumatic events were associated with occurrence of PTSD.

Incidence of major depressive disorder and dysthymia in young adolescents

OBJECTIVE

An epidemiological study conducted between 1987 and 1989 in a single school district in the southeastern United States investigated the incidence, transition probabilities, and risk factors for major depressive disorder (MDD) and dysthymia in adolescents aged 11 to 16 years.

METHOD

Diagnoses were based on the Schedule for Affective Disorders and Schizophrenia for School-Age Children, which was administered to 247 mother-adolescent pairs at 12-month intervals.

RESULTS

One-year MDD and dysthymia incidences were 3.3% (n = 11) and 3.4% (n = 9), respectively. Transition probabilities demonstrated movement from disorder to no disorder over time. Family cohesion (odds ratio = 0.95) was the only significant predictor of incident MDD. No factors were significant for dysthymia. While baseline MDD was a significant risk factor for depression at follow-up, 80% of subjects with baseline MDD did not meet the criteria for diagnosis at follow-up.

CONCLUSION

Findings suggest perceived family support or cohesion may be more important to adolescent mental health than family structure.

Incidence of obsessive-compulsive disorder in a community sample of young adolescents

OBJECTIVE

To investigate the incidence, transition probabilities, and risk factors for obsessive-compulsive disorder (OCD) and subclinical OCD in adolescents.

METHOD

A two-stage epidemiological study originally designed to investigate depression was conducted between 1987 and 1989 in the southeastern United States. For the screening, a self-report depressive symptom questionnaire was administered to a community sample of 3,283 adolescents. In the diagnostic stage, the Schedule for Affective Disorders and Schizophrenia for School-Age Children was administered to 488 mother-child pairs. Baseline screening and diagnostic data from the first year the subject completed an interview and follow-up diagnostic data from subsequent years were used.

RESULTS

The 1-year incidence rates of OCD and subclinical OCD were found to be 0.7% and 8.4%, respectively. Transition probabilities demonstrated a pattern of moving from more severe to less severe categories. Of those with baseline OCD, 17% had the diagnosis of OCD at follow-up; 62% moved to the referent group. Of those with baseline subclinical OCD, 1.5% had OCD at follow-up and 75% moved to the referent group. Black race (odds ratio [OR] = 23.38), age (OR = 4.02), desirable life events (OR = 0.78), undesirable life events (OR = 1.21), and socioeconomic status (OR not estimable) were significant predictors of incident OCD. Age (OR = 2.30), desirable life events (OR = 0.92), and undesirable life events (OR = 1.13) were significantly associated with incident subclinical OCD.

CONCLUSION

An initial diagnosis of subclinical OCD was not significantly predictive of a diagnosis of OCD at 1-year follow-up. The overall morbidity remained higher at follow-up in the baseline OCD group than in the baseline subclinical OCD group. The baseline subclinical OCD group was more dysfunctional at follow-up than was the baseline referent group. Further research concerning differences in symptomatology and impairment between OCD and subclinical OCD is warranted.

Frequency of phobic disorder in a community sample of young adolescents

OBJECTIVE

To investigate the frequency and phenomenology of clinical, subsyndromal, and subthreshold phobias in young adolescents.

METHODS

A two-stage epidemiological study originally designed to investigate adolescent depression was conducted between 1986 and 1988 in the southeastern United States. In the first stage, a self-report depressive symptom questionnaire was administered to a community sample of 3,283 adolescents. In the diagnostic stage, the Schedule for Affective Disorders and Schizophrenia for School-Age Children and the Children's Global Assessment Scale were administered to 487 mother-child pairs.

RESULTS

Prevalence rates of clinical, subsyndromal, and subthreshold phobia were 2.3%, 14.5%, and 22.2%, respectively. One-year incidence rates were 0.4%, 8.0%, and 16.9%, with 43.0% of phobic subjects categorized at the same or a more severe level after a year. Females, blacks, subjects not living with both biological parents, and older adolescents were more likely to meet the diagnostic criteria for clinical phobia. The majority (77%) of subjects with clinical phobia experienced multiple phobias. Subsyndromal (52%) and subthreshold (74%) phobics were more likely to experience simple phobias only.

CONCLUSIONS

Phobic symptoms are relatively common at a moderate level and in the majority of adolescents are somewhat transitory in nature. Characteristic symptomatology and comorbidity may facilitate earlier identification of subjects at risk of persistent symptomatology and in need of treatment.

Posttraumatic stress disorder in adolescents after Hurricane Andrew

OBJECTIVE

To examine rates and correlates of posttraumatic stress disorder (PTSD) in adolescents after Hurricane Andrew.

METHOD

A random-digit dialing sample of 158 Hispanic, 116 black, and 104 white adolescent-parent pairs were surveyed in high- and low-impact areas within Dade County, Florida, 6 months after Hurricane Andrew. Subjects completed a structured telephone interview focused on within-disaster experiences and emotional reaction, disaster-related losses, lifetime exposure to violent or traumatic events, recent stressful experiences, and psychiatric symptomatology.

RESULTS

Approximately 3% of males (95% confidence interval 0.4 to 5.3) and 9% of females (95% confidence interval 4.6 to 13.7) met the criteria for PTSD. Rates were highest among blacks (8.3%, 95% confidence interval 2.3 to 14.2) and Hispanics (6.1%, 95% confidence interval 2.2 to 9.9) and increased with age (odds ratio of 1.34, 95% confidence interval 1.04 to 1.72) and the number of undesirable events reported (odds ratio of 1.38, 95% confidence interval 1.21 to 1.57).

CONCLUSIONS

While only a relatively small percentage of adolescents reported symptoms consistent with a diagnosis of PTSD, most reported some posttraumatic symptoms. Postdisaster planning should recognize that common stressful events occurring after disasters may be more strongly associated with PTSD than magnitude of contact with the actual disaster.

Maternal serum placental alkaline phosphatase level and risk for preterm delivery

OBJECTIVE

The purpose of this study was to determine whether elevated midtrimester serum placental alkaline phosphatase levels are predictive of preterm delivery.

STUDY DESIGN

By use of banked serum specimens from a sample of women who had received maternal serum alpha-fetoprotein screening, placental alkaline phosphatase values for multiples of the median were obtained from 270 mothers who had experienced a preterm delivery and from 1598 mothers of term, appropriate-for-gestational-age infants. Specimens were analyzed for placental alkaline phosphatase by means of a monoclonal antibody enzyme-linked immunosorbent assay. Logistic regression was used to determine whether placental alkaline phosphatase was associated with preterm birth, while potential confounders were controlled for.

RESULTS

Women with placental alkaline phosphatase levels > or = 2.0 multiples of the median were significantly more likely to be delivered of a preterm infant in the current pregnancy compared with women with levels < 2.0 multiples of the median (odds ratio 2.9, 95% confidence interval 2.1 to 3.9). The likelihood of preterm birth increased significantly with higher multiples of the median (p < 0.001).

CONCLUSION

Women with elevated placental alkaline phosphatase levels are at increased risk for preterm delivery. Additional studies are needed to evaluate the clinical utility of placental alkaline phosphatase testing as a means of identifying mothers at risk for preterm birth.

Primary infertility and oral contraceptive steroid use

OBJECTIVE

To determine the association between combined monophasic oral contraceptive (OC) use and primary infertility.

DESIGN

Case-control.

SETTING

Women serving as controls of the Cancer and Steroid Hormone Study.

PARTICIPANTS

Women were 19 to 40 years of age at first conception or infertility diagnosis. Based on 24 consecutive months of unprotected intercourse without a recognized conception, 419 nulligravid women had primary infertility; controls were 2,120 fertile women. A calendar of each women's reproductive history was used to determine fertility status and contraceptive use before infertility diagnosis or first conception.

MAIN OUTCOME MEASURE

Primary infertility.

RESULTS

Combined monophasic OC use was associated with a lower frequency of primary infertility, particularly among younger (age 20 years) compared with older women (age 30 years) after adjusting for barrier method use and education. A similar association was found for duration of OC use. When adjusted for age at first conception or infertility and barrier method, both higher (> 50 micrograms) and lower (< or = 50 micrograms) estrogen dose use were associated with decreased risk of primary infertility.

CONCLUSION

Combined monophasic OC use was associated with a lower frequency of primary infertility.

Frequency of obsessive-compulsive disorder in a community sample of young adolescents

OBJECTIVE

To investigate the frequency and phenomenology of obsessive-compulsive disorder (OCD) and subclinical OCD in young adolescents.

METHOD

A two-stage epidemiological study originally designed to investigate adolescent depression was conducted between 1986 and 1988 in the southeastern United States. In the first stage, a self-report depressive symptom questionnaire was administered to a community sample of 3,283 adolescents. In the diagnostic stage, the Schedule for Affective Disorders and Schizophrenia for School-Age Children and the Children's Global Assessment Scale were administered to 488 mother-child pairs.

RESULTS

The prevalences of OCD and subclinical OCD were found to be 3% and 19%, respectively. Prevalences were similar in males and females. Females reported more symptoms of compulsions although males reported more obsessions. About 55% of adolescents with OCD reported both obsessions and compulsions. The most common compulsions were arranging (56%), counting (41%), collecting (38%), and washing (17%). Major depressive disorder (45%), separation anxiety (34%), dysthymia (29%), suicidal ideation (15%), and phobia (8%) were the diagnoses most frequently comorbid with OCD.

CONCLUSIONS

Findings suggest that OCD is not infrequent among adolescents and that the characteristic comorbidity and symptomatology of OCD may facilitate earlier identification and treatment by clinicians.

Confidence intervals for weighted proportions

We investigate methods for the construction of confidence intervals for a proportion in a stratified two-stage sampling design with few events occurring in a small number of large, unequal size strata. The critical aspect is the incorporation of the weighting scheme into the construction of a single overall confidence interval. With small numbers of events, the binomial based methods may be inadequate since the normal approximation is not valid. Computer simulations compare coverage probability and bias for five methods of obtaining confidence intervals for proportions by combining: (1) binomial variances; (2) confidence intervals based on the F-distribution approximation to the cumulative binomial; (3) the binomial variance method with exact confidence limits when a zero prevalence occurs in any stratum; (4) confidence intervals based on the F-distribution using a rescaling factor; and (5) the binomial variance method with exact confidence limits using a rescaling factor. The method that performs best in terms of coverage probability is the combination of stratum specific confidence intervals based on the F-distribution using a rescaling factor. The methods involving the binomial variance tend to be negatively biased and the methods based on the F-distribution tend to be positively biased. Application of these methods with data from a study of adolescent depression that employs a stratified two-stage sampling design is consistent with these results.

The prognostic value of a risk score for necrotising enterocolitis

Necrotising enterocolitis is the most common severe acquired gastrointestinal disorder in the neonate yet there remains disagreement on predictive and prognostic factors. A previously published risk score purports to predict infants at greater risk of the disease. Fifty-nine cases and 59 matched controls were evaluated using data from the first 24 h after birth to determine the predictive and prognostic value of the score for necrotising enterocolitis. In simple models the risk score was significantly, but inversely, associated with necrotising enterocolitis, primarily due to greater respiratory problems among controls. This finding contrary to the premise is clarified by a significant interaction of the risk score with feeding variables. Odds ratios for the risk score varied at different levels of daily feeding increments. However, the risk score was not statistically significant in any models which controlled for feeding increment and the interaction. The risk score was significantly associated with mortality among necrotising enterocolitis cases. Though the score was not statistically significant when the outcome was disease stage or surgery, trends were in the expected direction. The data suggest that the risk score itself may not be an independent predictor of necrotising enterocolitis, but may indicate infants more vulnerable to other potential risk factors and, in addition, may be related to prognosis for those who do develop necrotising enterocolitis.

Mother-adolescent agreement on the symptoms and diagnoses of adolescent depression and conduct disorders

OBJECTIVE

To determine rates and correlates of mother-adolescent agreement on the symptoms and diagnoses of depression and conduct disorders.

METHOD

The Schedule for Affective Disorders and Schizophrenia in School Age Children was administered to a community sample of 460 adolescents and their mothers. Race, gender, family adaptability and cohesion, and living arrangement were evaluated as predictors of agreement.

RESULTS

Mother-adolescent agreement was low (kappa < 0.40) for all diagnoses and symptoms with these exceptions: feeling tired (kappa = 0.40), inattention (kappa = 0.50), vandalism (kappa = 0.50), and chronic violation of rules (kappa = 0.72). Cohesion and adaptability were associated with mother-adolescent agreement on the symptoms and diagnosis of depression. This association was not demonstrated as consistently for agreement on the symptoms and diagnosis of conduct disorders.

CONCLUSION

Study findings underscore the necessity of collecting data from both a parent and the adolescent when assessing an adolescent's psychological status.

Oral contraceptive use and breast cancer in Indonesia

A hospital-based case-control study was conducted in Ujungpandang, Indonesia, to determine the association of breast cancer and current and former oral contraceptive (OC) use. This study included 119 newly diagnosed, histologically-confirmed, breast cancer cases who were admitted to the four largest referral hospitals in Ujungpandang from 1990-1991. Controls were 258 women admitted to these same four hospitals with diagnoses unrelated to breast cancer or OC use. Thirty cases (32%) and 55 (19%) controls reported having ever used OCs. The odds ratio for ever using OCs and breast cancer was 1.8 (95% confidence interval 1.2-3.0) after adjustment for age, age at first pregnancy, and family history of breast cancer. Increasing duration of OC use did not increase risk of breast cancer. No latency trend of increasing years since first OC use among cases was observed; however, a younger age at first OC use was associated with increasing breast cancer risk. A significant recency effect was observed; women last using OCs within five years of study enrollment were at greatest risk of breast cancer (OR = 4.9, 95% CI: 2.1-11.4). This first study of breast cancer and OC use in Indonesia does not provide consistent data to indicate an increased risk of breast cancer associated with OC use. Although breast cancer cases were 80% more likely to have ever used OCs, neither duration nor latency of OC use were associated with cancer risk. The significant recency effect suggests that a detection bias might explain the observed relationship between ever OC use and breast cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Tuberculosis and AIDS in South Carolina: a case-control study

The epidemiologic features of tuberculosis patients with AIDS or HIV infection in this study do not appear to be different from those reported from previous studies. Tuberculosis patients with AIDS or HIV positive antibody in South Carolina are predominantly black males who live in the urban areas and are 25 to 44 years old. They have more extrapulmonary sites and more anergic reactions to tuberculin tests. Physicians and other public health workers should be aware of the abnormal clinical and laboratory manifestations of tuberculosis patients with AIDS and HIV infection. It is also imperative for tuberculosis control programs to offer counseling and HIV antibody testing to tuberculosis patients.

Role of delayed feeding and of feeding increments in necrotizing enterocolitis

In spite of a number of studies on necrotizing enterocolitis, there remains controversy concerning prevention regimens, especially with regard to enteral alimentation. This report is of a matched case-control study of the relationship of necrotizing enterocolitis to timing of first feeding, size of feeding volumes and increments, and a risk factor index in 59 case patients with necrotizing enterocolitis and 59 matched control patients. Comparison with control patients showed that case patients were fed earlier, received full-strength formula sooner, and received larger feeding volumes and increments. More highly stressed infants, as measured by the risk index, were more vulnerable to larger feeding increments. Among case patients there was significant correlation of age at first feeding and age at diagnosis (p < 0.0001) even after control for birth weight and risk index score, indicating that delayed feeding was related to delayed onset of disease. These analyses support the theory that earlier, more rapid feeding places stressed infants at greater risk for the development of necrotizing enterocolitis, and that infants with more severe respiratory problems are more vulnerable to such feeding practices.

Major depressive disorder and dysthymia in young adolescents

A two-stage epidemiologic study conducted between 1986 and 1988 in the southeastern United States investigated the frequency of major depressive disorder and dysthymia in 12-14 year olds. In stage one, the Center for Epidemiologic Studies Depression Scale, a life event schedule, and a family cohesion scale were administered to a community sample of 3,283 adolescents. In stage two, 488 mother-child pairs were interviewed utilizing the Schedule for Schizophrenia and Affective Disorders in School Age Children. Although mean Center for Epidemiologic Studies Depression Scale scores were significantly higher in females (25.60) than in males (19.50), prevalence estimates based on a summary of mother and child symptom reports for Diagnostic and Statistical Manual of Mental Disorders, Third Edition, major depressive disorder were similar: 9.04% in males and 8.90% in females. The prevalences of dysthymia were 7.98% in males and 5.00% in females. Previous investigations have reported lower rates and a female preponderance of major depression. Disagreement between mothers and children regarding the presence of symptoms may explain this contradiction. Significant odds ratios were found between major depression and not living with both natural parents (odds ratio (OR) = 3.89), undesirable life events (OR = 1.09), and perceived family cohesion (OR = 0.96). Not living with both natural parents (OR = 14.67) and socioeconomic status (OR = 0.44) were significant correlates of dysthymia.

A generalized stochastic model for the analysis of infectious disease final size data

A stochastic infectious disease model was developed by Ball (1986, Advances in Applied Probability 18, 289-310) in which the distribution of the length of the infectious period is allowed to have any distribution that can be described by its Laplace transform. We extend this model such that the infection can be transmitted within the population or from an unspecified source outside the population. Also, discrete heterogeneity in the population can be modeled to incorporate variable susceptibility, variable infectivity, and/or mixing behaviors. The model is fitted to serologic data from two influenza epidemics in Tecumseh, Michigan, using maximum likelihood estimation procedures. The estimates show a clustering pattern by age groups.

The CES-D as a screen for depression and other psychiatric disorders in adolescents

The performance of the Center for Epidemiologic Studies Depression Scale (CES-D) as a screen for depression was explored in a two-stage epidemiological study of adolescents. The study consisted of a CES-D screening stage completed by a school sample of 2,465 young adolescents and a structured psychiatric interview stage completed by 332 mother-adolescent pairs. Adolescents with interview validated depression had elevated screening scores (mean = 31.10, SD = 11.30) compared with individuals with no disorder (mean = 21.01, SD = 11.77). Using receiver operating characteristic curves, a cut point of 12 for males produced the best overall screening characteristics (sensitivity = 0.85, specificity = 0.49), while for females, a cut point of 22 was optimal (sensitivity = 0.83, specificity = 0.77).

A longitudinal study of suicidal ideation in young adolescents

As part of a longitudinal study of depression and suicidal ideation in adolescents, a three-item suicide screen was administered to 1,073 students for 3 consecutive years starting at the beginning of the 7th or 8th grades. Each year over 70% of respondents reported no suicidal thoughts, and less than 5.5% attained high suicide ideation scores. Blacks and females had higher scores, respectively, than did whites and males. The individual students' suicide scores were less stable than the overall distributions with 1- and 2-year correlations reaching 0.35 and 0.28, respectively. Only one student received a high score all 3 years. The best predictors of a given year's suicide score was the previous years' depression scores. Gender, undesirable life events, family adaptability, and family cohesion were significant but less consistent predictors.

Suicidal behaviors in young adolescents

A two-stage epidemiologic study investigated the frequency of suicidal behavior in children 12-14 years of age. In the first stage, the Center for Epidemiologic Studies Depression Scale, a three-item suicide scale, a life-event schedule, and a family environment scale were administered during 1986 to a southeastern US community sample of 1,542 seventh and eighth grade students. In the second stage, 226 mother-child pairs were interviewed utilizing the Schedule for Schizophrenia and Affective Disorders in School Age Children (K-SADS). Subjects interviewed included students with high depression scores and a random sample of the remaining students. Prevalence estimates for moderate to severe suicidal ideation (K-SADS score greater than or equal to 4) were 4.0% (95% confidence interval (CI) 0.6-16.4%) in males and 8.7% (95% CI 2.4-23.3%) in females. The prevalences of suicide attempts were 1.9% (95% CI 0.0-13.2%) in males and 1.5% (95% CI 0.6-12.7%) in females. Significant relations were found between major depression and both suicide ideation (odds ratio = 6.19, 95% CI 1.53-24.94) and suicide attempts (odds ratio = 9.80, 95% CI 1.89-50.86). The undesirable life-events score was also a significant predictor of suicide ideation and suicide attempts.

Dengue epidemics on the Pacific Coast of Mexico

Dengue epidemics in three Mexican cities were investigated with retrospective surveys and virus isolations from acute cases. These epidemics were part of the continuing extension of dengue in Mexico since 1978 after 15 years without transmission. Serotype 1 dengue infection predominated in all epidemics, but in one city, type 2 strains were also isolated. The following findings were consistent in all three cities: 1) illness history provided evidence of presence of infection months before the epidemic became evident, 2) there was a very sharp and progressive increase of dengue illness attack rates by age, 3) there were no interpretable relationships between illness and the presence of different types of breeding sights in the home, 4) socioeconomic status was strongly negatively related to illness, and 5) geographical factors not related to the other measured variables had a strong effect on illness rates reflecting the focality of transmission. In addition, there was evidence of a strong protective effect against illness by the use of mosquito netting or the presence of screens on houses, but these relationships were not universal to all three cities.