Biomedical subjects

J D Killen

Publications and source records attributed to J D Killen.

At least 37 records · Page 2Linked to original sources

PubMed1998

Characteristics of successful and unsuccessful dieters: an application of signal detection methodology.

Signal detection methods were used to identify predictors of successful weight loss in 177 mildly to moderately overweight women and men assigned to one of two weight-loss programs. Predictors included initial demographic, physiological, behavioral, and psychosocial characteristics, and program type (e.g. diet-only and diet-plus-exercise). Successful weight loss was defined as a loss of at least two units of body mass index at one year. Four subgroups were identified. Participants in the diet-plus-exercise program who were initially more satisfied with their bodies and did not have a history of repeated weight loss were most likely to succeed (63% succeeded). In contrast, participants assigned to the diet-plus-exercise program who were either extremely dissatisfied with their bodies or who had a history of repeated weight loss were at similar risk for failure as participants in the diet-only program (only 26% to 35% succeeded). The results underscore the potential utility of exploring these subgroups further to inform the development of new treatment strategies to increase the likelihood of success.

Adult↗

PubMed1998

Age of onset for binge eating and purging during late adolescence: a 4-year survival analysis.

This prospective study examined age of onset for binge eating and purging among girls during late adolescence and tested whether dieting and negative affectivity predicted these outcomes. Of initially asymptomatic adolescents, 5% reported onset of objective binge eating, 4% reported onset of subjective binge eating, and 4% reported onset of purging. Peak risk for onset of binge eating occurred at age 16, whereas peak risk for onset of purging occurred at age 18. Adolescents more often reported onset of a single symptom rather than multiple symptoms, and symptoms were episodic. Dieting and negative affectivity predicted onset of binge eating and purging. Findings suggest that late adolescence is a high-risk period for onset of bulimic behaviors and identify modifiable risk factors for these outcomes.

Adolescent↗

PubMed1998

Linking self-reported childhood behavioral inhibition to adolescent social phobia.

OBJECTIVE: Behavioral inhibition in children has been hypothesized to be a risk factor for the later development of social phobia. However, this hypothesis has yet to be demonstrated in a prospective study. The purpose of the study presented here is to test whether behavioral inhibition in childhood constitutes a risk factor for social phobia during adolescence. METHOD: The sample consisted of 2,242 high school students assessed over a 4-year period. Assessments included self-report questionnaires, structured clinical interviews, and measurements of heart rate. Cox proportional hazards models were used to evaluate risk. RESULTS: Social avoidance, a component of behavioral inhibition, predicted onset of social phobia during high school. However, social avoidance was not related to depression in adolescence. Another component of behavioral inhibition, fearfulness, increased the risk for both social phobia and depression. Among subjects who were both socially avoidant and fearful, 22.3% developed social phobia--a risk more than four times greater than that for subjects with neither feature of behavioral inhibition. CONCLUSION: This prospective study demonstrates that behavioral inhibition in childhood increases the risk of social phobia in adolescence.

Adolescent↗

PubMed1998

Psychosocial factors associated with youth involvement in community activities promoting heart health.

This study examined factors that influence youth participation in heart disease prevention activities among 2,609 ninth graders in six inner-city public high schools. Constructs derived from social cognitive, empowerment, and community development theories informed the conceptual framework employed. Study participants were diverse with respect to gender, ethnicity, parent education, acculturation, and academic achievement. Perceived incentive value, self-efficacy, outcome expectancies, sense of community, and perceived policy control were all significantly associated with participation in community activities promoting heart health. In multivariate analyses, perceived incentive value, defined as the extent to which participants valued a heart-healthy environment, was most strongly associated with community participation, accounting for 11.9% of the total variance. These findings have implications for designing school curricula and after-school and community programs targeting adolescents' involvement in health advocacy activities.

Adolescent↗

PubMed1998

Television and music video exposure and risk of adolescent alcohol use.

OBJECTIVE: Alcohol use is frequently portrayed in television programming and advertising. Exposure to media portrayals of alcohol use may lead to increased drinking. To address this issue, we examined prospectively the associations between media exposure and alcohol use in adolescents. DESIGN: Prospective cohort study. Setting. Six public high schools in San Jose, California. Participants. Ninth-grade students (N = 1533; mean age = 14.6 years). OUTCOME MEASURES: Students reported hours of television, music video, and videotape viewing; computer and video game use; and lifetime and past 30 days' alcohol use at baseline and 18 months later. Associations between baseline media exposure and subsequent alcohol use were examined with multiple logistic regression. RESULTS: During the 18-month follow-up, 36.2% of baseline nondrinkers began drinking and 50.7% of baseline drinkers continued to drink. Onset of drinking was significantly associated with baseline hours of television viewing (odds ratio [OR] = 1.09; 95% confidence interval [95% CI] = 1.01-1.18), music video viewing (OR = 1.31; 95% CI = 1. 17-1.47), and videotape viewing (OR = 0.89; 95% CI = 0.79-0.99), controlling for age, sex, ethnicity, and other media use. Computer and video game use was not significantly associated with the subsequent onset of drinking. Among baseline drinkers, there were no significant associations between baseline media use and maintenance of drinking. CONCLUSIONS: Increased television and music video viewing are risk factors for the onset of alcohol use in adolescents. Attempts to prevent adolescent alcohol use should address the adverse influences of alcohol use in the media.

Adolescent↗

PubMed1998

Support for the continuity hypothesis of bulimic pathology.

There has been debate as to whether bulimia represents the endpoint of an eating disorder continuum (the continuity hypothesis) or is categorically different from subthreshold bulimia or an absence of eating disorders (the discontinuity hypothesis). The present study tested whether differences among bulimic, subthreshold bulimic, and control women on weight-concern and psychopathology variables better accord with the continuity or discontinuity hypothesis. These 3 groups were compared on body mass, thin-ideal internalization, body dissatisfaction, dietary restraint, depressive symptoms, anxiety symptoms, and temperamental emotionality. Discriminant function analysis and follow-up pairwise contrasts indicated that the continuity hypothesis was supported for measures of both weight concern and psychopathology. Research and treatment implications of the continuity perspective are discussed.

Adolescent↗

PubMed1997

Do cigarette warning labels reduce smoking? Paradoxical effects among adolescents.

OBJECTIVE: To examine the association between adolescents knowledge of cigarette warning labels and actual smoking behavior. DESIGN: Cohort analytic study. SETTING: Four public high schools in northern California. SUBJECTS: Seventeen hundred forty-seven ninth graders (mean age, 14.9 years). Students from 2 of the schools (n = 803) were observed for approximately 3 months. MAIN OUTCOME MEASURES: Self-reported knowledge of warning labels was assessed at baseline. Self-reports of smoking behavior were completed at baseline and at follow-up. RESULTS: Greater knowledge of cigarette package warning labels was significantly associated with higher levels of smoking. Knowledge of warning labels on magazine and billboard advertisements did not differ significantly by level of smoking. In the longitudinal sample, greater knowledge of cigarette package warning labels was significantly associated with a subsequent increase in smoking, controlling for the baseline level of smoking, sex, ethnicity, and knowledge of warning labels on cigarette advertisements (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.02-1.46). Knowledge of warning labels on cigarette advertisements was not associated with a significant change in smoking behavior (OR, 1.06; 95% CI, 0.82-1.35). CONCLUSIONS: Sizable proportions of adolescent smokers are not seeing, reading, or remembering cigarette warning labels. In addition, knowledge of warning labels on cigarette packages and advertisements is not associated with reduced smoking. The current warning labels are ineffective among adolescents.

Adolescent↗

PubMed1997

Nicotine patch and self-help video for cigarette smoking cessation.

A total of 424 smokers were randomized in a 2 x 2 factorial experiment. A pharmacologic factor contained 2 levels: transdermal nicotine path (TNP; 21 mg) and placebo. A self-help behavioral treatment factor contained 2 levels: video-enhanced self-help treatment manual and self-help treatment manual only. At 2 months, TNP produced a higher level of abstinence (36%) than placebo (20%), p < .001. No other comparison was significant. In secondary analyses, (at 2 months) and compliance with patch treatment regimen (at 2, 6, and 12 months) were associated with less relapse. Although nicotine replacement therapy has improved our ability to produce smoking cessation, the production of sustained, longer term abstinence remains an elusive goal.

Administration, Cutaneous↗

PubMed1997

Prospective study of risk factors for the initiation of cigarette smoking.

Risk factors for the initiation of cigarette smoking were examined in 2 consecutive cohorts of teenagers (N = 1,901). Students in Cohort 1 were followed over 4 years from 9th to 12th grade; those in Cohort 2 were followed over 3 years from 9th to 11th grade. Among girls with no history of smoking at baseline, those with more friends who smoked at baseline (p < .001) and those with higher sociability scores (p < .05) were significantly more likely to have tried smoking over the study interval. Among boys with no history of smoking at baseline, those with more friends who smoked at baseline (p < .05) and those with higher depression symptoms scores (p < .01) were significantly more likely to have tried smoking over the study interval. The data suggest that future research is needed to examine potential gender differences that may have implications for the next generation of smoking-prevention programs.

Adolescent↗

PubMed1997

Craving is associated with smoking relapse: findings from three prospective studies.

In a combined sample of more than 2600 smokers, immediate postcessation craving is shown to be prospectively associated with smokers' ability to maintain abstinence. Relapse is strikingly rapid among those reporting high levels of craving following cessation. More than 32% of those with high craving scores relapsed within 1 week of cessation. In contrast, fewer than 15% of those with low craving relapsed in the first week (p < .001). Our findings provide a warrant for an increased research effort designed to provide a better understanding of the factors that control following smoking cessation and the processes by which craving influences smoking relapse.

Administration, Cutaneous↗

PubMed1997

Psychiatric risk associated with early puberty in adolescent girls.

OBJECTIVE: This study prospectively evaluated the relationship between early puberty and the onset of internalizing symptoms and disorders in adolescent girls. METHOD: The sample was drawn from 1,463 sixth-, seventh-, and eighth-grade girls who participated in a longitudinal school-based study of growth and development. Pubertal stage was determined by self-assessment of Tanner stage. Psychiatric assessments included self-report instruments and structured diagnostic interviews. Survival methods were utilized for data analysis. RESULTS: Girls with onset of internalizing symptoms were on average 5 months earlier in pubertal development than those who were asymptomatic (p < .001). In addition, girls with earlier maturation (earliest quartile) were more likely to develop internalizing symptoms than were nonearly matures (hazard ratio = 1.8, confidence interval = 1.2, 2.7). In a subsample of girls followed into high school, early-maturing girls were at marginally higher risk (p < .10) for developing internalizing disorders by the study's end. The highest risk for internalizing disorders was for those girls with both early puberty and prior internalizing symptoms (odds ratio = 3.3). CONCLUSION: Early puberty increases the risk of internalizing symptoms and perhaps internalizing disorders in adolescent girls.

Chi-Square Distribution↗

PubMed1996

Ethnicity and body dissatisfaction: are Hispanic and Asian girls at increased risk for eating disorders?

PURPOSE: To compare prevalences and correlates of body dissatisfaction among white, Hispanic, and Asian girls. METHODS: A total of 939 6th and 7th grade girls (mean age 12.4 years) attending four middle schools in northern California completed self-administered assessments of age, ethnicity, desired body shape, parent education levels, mother's and father's body shapes, pubertal stage, and body dissatisfaction. Body dissatisfaction was assessed with the Body Dissatisfaction scale of the Eating Disorder Inventory. Height, weight, triceps skinfold thickness, and waist and hip circumferences were measured by trained examiners. RESULTS: Hispanic girls reported significantly greater body dissatisfaction than white girls, with Asian girls in-between. After adjustment for body mass index (weight/height), normal and overweight white, Hispanic, and Asian girls reported similar levels of body dissatisfaction. However, among the leanest 25% of girls, Hispanics and Asians reported significantly more body dissatisfaction than white girls. Body mass index was the strongest independent predictor of increased body dissatisfaction in all three ethnic groups. Shorter height among white girls and taller height among Asian girls also made significant independent contributions. Parent education level, a measure of socioeconomic status, was not significantly associated with body dissatisfaction. CONCLUSIONS: Body dissatisfaction is not limited to white girls in middle and upper socioeconomic strata. These findings suggest Hispanic and Asian girls may be at greater risk for adopting eating disorder behaviors than previously recognized.

Adolescent↗

PubMed1996

Interactive effects of depression symptoms, nicotine dependence, and weight change on late smoking relapse.

Signal detection methods were used to develop an algorithm useful in distinguishing those at risk for late relapse from those likely to maintain abstinence. Four subgroups with 24-month survival (nonrelapse) rates ranging from 79% to 33% were identified. Among participants whose depression symptoms decreased from baseline to the end of treatment, lower levels of nicotine dependence were associated with less relapse at the 24-month follow-up (odds ratio = 2.77; 95% confidence interval: 1.36-5.62). Among participants whose depression symptoms increased from baseline to the end of treatment, greater weight gain was associated with less relapse at follow-up (odds ratio = 2.90; 95% confidence interval: 1.41-5.96). This study suggested that it may become possible to use both baseline and treatment information to "titrate" interventions.

Algorithms↗

PubMed1996

Weight concerns influence the development of eating disorders: a 4-year prospective study.

The authors examined factors prospectively associated with age of onset of partial syndrome eating disorders over a 4-year interval in a community sample (N = 877) of high school-age adolescent girls. Four percent developed a partial syndrome eating disorder over the interval. A measure of weight concerns was significantly associated with onset in a multivariate Cox proportional hazard analysis (p < .001). Girls scoring in the highest quartile on the measure of weight concerns had the highest incidence (10%) of partial syndrome onset, whereas none of the girls in the lowest quartile developed eating disorder symptoms. This finding is consistent with both theoretical and clinical perspectives and may represent a useful step toward the establishment of a rational basis for the choice of a prevention intervention target.

Adolescent↗

PubMed1995

Nicotine gum and self-help behavioral treatment for smoking relapse prevention: results from a trial using population-based recruitment.

Smokers aged 18 to 65 years (N = 1,044) who were able to quit for 24 hr were randomized using a 2 x 2 factorial design to compare nicotine gum to no gum use and self-help materials to no use of materials. All participants were offered a $100 incentive to quit and stay quit for 6 months. Six-month abstinence was 27% in the gum groups, compared with 19% in the no-gum group (p = .002). Compared with the no-gum group, relapse occurred at a significantly lower rate in the gum group for the entire 12 months of follow-up (odds of relapse in the gum group was 0.72, 95% confidence interval, 0.62 to 0.83). There was no significant main effect for the self-help materials, no interaction between gum and materials, and no evidence that the effectiveness of gum differed between the sexes or between heavy and light smokers. Nicotine gum is an effective adjunct to minimal-contact smoking cessation materials plus monetary incentive in a population-based sample of smokers.

Adult↗

PubMed1994

Who shall quit? Comparison of volunteer and population-based recruitment in two minimal-contact smoking cessation studies.

To better understand the generalizability of experimental smoking studies, the authors compare volunteer and population-based recruitment in two randomized clinical trials of smoking cessation methods, one that used a volunteer sample and one that used a random, population-based sample. Participants are compared with nonparticipants within each study, to the participants in the other study, and to the general population. Smokers aged 18-65 years without contraindications to using nicotine polacrilex who were able to quit unassisted were eligible for the two studies. In the first study (1984-1989), advertising recruited 3,758 eligible smokers (75% of all inquiries) who were willing to give a baseline telephone interview. Of these 3,758 eligible smokers, 2,592 attempted to quit and 1,226 succeeded for 48 hours and were randomized. In the second study (1988-1993), 7,135 smokers were identified through a random household telephone survey, and of these 7,135 smokers, 5,124 (72%) agreed to the telephone interview, 2,209 made a quit attempt, and 1,170 succeeded for 24 hours and entered the study. Compared with nonparticipants who provided an interview, subjects in both studies were more likely to be male, married, and employed, and were older and better educated. Compared with population-based recruitment, volunteer recruitment produced subjects who were less likely to be male and married, and were older, more educated, only slightly less representative of all ethnic subgroups, and heavier, more addicted smokers. Women were less likely than men to quit in the first 24-48 hours. The authors conclude that volunteer recruitment to smoking cessation studies appears to produce a reasonable sample of smokers, especially of heavy smokers, and that, compared with men, women may have more difficulty with the initial stages of smoking cessation.

Adolescent↗

PubMed1994

Timing and rate of sexual maturation and the onset of cigarette and alcohol use among teenage girls.

OBJECTIVE: To test the hypothesis that the patterns of pubertal progression, early vs late puberty and fast vs slow, are associated with the age at which girls start to drink alcohol and smoke cigarettes. DESIGN: The study included 1463 female students, 10.7 to 18.2 years of age, who were assessed five times during the 2.7-year study. Data regarding pubertal stage, alcohol use, and cigarette use were obtained at each assessment. These data were used to calculate two indexes of pubertal development, the age at which the midpoint of puberty was achieved and the rate of progression through puberty, and the ages when each subject first drank, first drank moderate amounts of alcohol, and first smoked. RESULTS: Girls with earlier puberty (midpoint < 12.2 years) first reported drinking any alcohol at a median age of 12.5 years, 0.7 years younger than girls whose puberty was later. Similarly, girls with earlier puberty reported drinking moderate amounts of alcohol at a median age of 13.7 years, 0.9 years younger than girls with later puberty. Girls with earlier puberty further reported first smoking cigarettes at a median age of 12.8 years, 0.6 years younger than girls with later puberty. The rate of pubertal progression was significantly associated only with the age when girls first drank moderate amounts of alcohol. CONCLUSION: Earlier puberty is associated with a younger age of onset for both drinking and smoking among adolescent girls.

Adolescent↗

PubMed1994

Pursuit of thinness and onset of eating disorder symptoms in a community sample of adolescent girls: a three-year prospective analysis.

Community-based prospective studies are needed to shed light on mechanisms that may influence development of eating disorders and identify variables that could serve as potential targets for prevention efforts. In this paper we examine level of weight preoccupation and other variables prospectively associated with age of onset of eating disorder symptoms over a 3-year interval in a community sample (N = 939) of young adolescent girls. 3.6% (32/887) experienced onset of symptoms over the interval. Only one factor, a measure of Weight Concerns, was significantly associated with onset (p < .001). Girls scoring in the highest quartile on the measure of Weight Concerns had the shortest survival time (12% incidence by age 14.5) and those scoring in the lowest quartile had the highest survival time (2% incidence by age 14.5; p < .001). This finding is consistent with both theoretical and clinical perspectives and represents one of the first prospective demonstrations of a linkage between weight and body shape concerns and later onset of eating disorder symptoms. An understanding of the independent variables that predispose girls to development of symptoms is a useful step towards the establishment of a rational basis for the choice of a prevention intervention target.

Adolescent↗