Evaluation of urinary trans-3'-hydroxycotinine as a biomarker of children's environmental tobacco smoke exposure.

The utility of urinary trans-3'-hydroxy cotinine (3HC) as a biomarker of environmental tobacco smoke (ETS) exposure was investigated in comparison with urinary cotinine (COT), the sum (3HC + COT), and ratio of the two nicotine metabolites (3HC/COT). Participants were 150 ETS exposed children (aged 1-44 months) and their parents. Child urine samples were collected during 3weekly baseline assessments and at interviews administered 3, 6, 12, and 18 months after baseline. Findings indicate that 3HC and COT can be measured reliably (rho = 0.96, 0.88) and show equivalent levels of repeated measures stability (rho = 0.71, 0.75). COT, 3HC, and 3HC + COT showed equally strong associations with air nicotine levels, reported ETS contamination, and reported ETS exposure (r=0.60-0.70). The intraclass correlations of 3HC/COT were lower than those for COT or 3HC. Older children had a higher 3HC/COT ratio than younger children (3.5 versus 2.2), and non-Hispanic White children had a higher ratio than African-American children (3.2 versus 1.9). These findings suggest that COT, 3HC, and 3HC + COT are approximately equivalent and equally strong biomarkers of ETS exposure in children. Moreover, 3HC/COT may provide a useful indicator to investigate age- and race-related differences in the metabolism of COT and 3HC.

Tobacco use and other risk behaviors: cross-sectional and predictive relationships for adolescent orthodontic patients.

BACKGROUND: The purpose of these analyses was to examine the prevalence of selected substance abuse, general and dental health risk, and scholastic risk behaviors and their cross-sectional and predictive relationships with tobacco use among 15, 179 adolescent orthodontic patients in Southern California. METHODS: Subjects were recruited through 154 orthodontists' offices and interviewed by telephone at baseline and two-year posttest. RESULTS: Results show a pattern of increasing prevalence of risk behaviors with age. In most cases, gender differences were small. There were statistically significant positive relationships between each risk behavior and tobacco use status for both boys and girls. Prevalence rates of risk behaviors other than tobacco use were highest for current smokers, intermediate for experimenters, and lowest for respondents reporting that they had never used tobacco. Baseline tobacco use predicted each posttest risk behavior in logistic regression analyses. Principle components analysis (with varimax rotation) of posttest risk practices other than tobacco use yielded three theoretically meaningful factors, all which were predicted by baseline tobacco use in multiple regressions. CONCLUSIONS: These findings show that tobacco use among adolescents can predict subsequent risk practices other than tobacco use as long as two years, and that unhealthy behaviors among teens are interrelated. Orthodontists, who have a high frequency of adolescent patient contact, may be in a unique position to deliver health promotion interventions to their patients; possibly targeting multiple risk behaviors.

Reported measures of environmental tobacco smoke exposure: trials and tribulations.

OBJECTIVE: This report extends previous summaries of reported environmental tobacco smoke (ETS) exposure measures, reviews the empirical evidence of their validity for children's exposure, and discusses future research. DATA SOURCES: Studies were identified by computer search and from the authors' research. STUDY SELECTION: Studies were selected for inclusion of nicotine and/or cotinine and quantitative reported measures of ETS exposure. DATA SYNTHESIS: Five studies found significant associations between reported quantitative exposure of children to ETS and either environmental nicotine or urine cotinine assays. Correlation coefficients between parent reports and nicotine ranged from 0.22 to 0.75. Coefficients for cotinine ranged from 0.28 to 0.71. Correlations increased over time and were stronger for parents' reports of their own smoking as a source of children's exposure than for reports of exposure from others. CONCLUSIONS: Empirical studies show general concordance of reported and either environmental or biological measures of ETS exposure. Relationships were moderate, and suggest sufficient validity to be employed in research and service programs. Future studies need to identify the differences in types of reported or objective measures, population characteristics, etc, contributing to observed variability in order to understand better the conditions under which more valid reported ETS exposure and other measures can be obtained. Reported and either environmental or biological measures should be used in combination, and existing measures should be directed to interventions that may reduce ETS exposure among children.

Effect of counselling mothers on their children's exposure to environmental tobacco smoke: randomised controlled trial.

OBJECTIVE: To test the efficacy of behavioural counselling for smoking mothers in reducing young children's exposure to environmental tobacco smoke. DESIGN: Randomised double blind controlled trial. SETTING: Low income homes in San Diego county, California. PARTICIPANTS: 108 ethnically diverse mothers who exposed their children (aged <4 years) to tobacco smoke in the home. INTERVENTION: Mothers were given seven counselling sessions over three months. MAIN OUTCOME MEASURES: Children's reported exposure to environmental tobacco smoke from mothers in the home and from all sources; children's cotinine concentrations in urine. RESULTS: Mothers' reports of children's exposure to their smoke in the home declined in the counselled group from 27.30 cigarettes/week at baseline, to 4.47 at three months, to 3.66 at 12 months and in the controls from 24.56, to 12.08, to 8.38. The differences between the groups by time were significant (P=0.002). Reported exposure to smoke from all sources showed similar declines, with significant differences between groups by time (P=0.008). At 12 months, the reported exposure in the counselled group was 41.2% that of controls for mothers' smoke (95% confidence interval 34.2% to 48.3%) and was 45.7% (38.4% to 53.0%) that of controls for all sources of smoke. Children's mean urine cotinine concentrations decreased slightly in the counselled group from 10.93 ng/ml at baseline to 10.47 ng/ml at 12 months but increased in the controls from 9.43 ng/ml to 17.47 ng/ml (differences between groups by time P=0.008). At 12 months the cotinine concentration in the counselled group was 55.6% (48.2% to 63.0%) that of controls. CONCLUSIONS: Counselling was effective in reducing children's exposure to environmental tobacco smoke. Similar counselling in medical and social services might protect millions of children from environmental tobacco smoke in their homes.

Measuring secondhand smoke exposure in babies: the reliability and validity of mother reports in a sample of low-income families.

The reliability and validity of mother's reports of their infants' exposure to secondhand smoke (SHS) were examined in an ethnically diverse sample of low-income, low-education families (N = 141 mothers). At baseline and posttest, smoking mothers reported about their infants' SHS exposure at different locations and by different sources during the previous week. Findings show that mothers can give reliable accounts of the degree to which they contribute to their babies' SHS exposure. Mothers are able to differentiate between their own smoking behavior and the extent to which they expose their infants. Consistent with the overall exposure pattern, exposure caused by the mother and exposure occurring at home showed the strongest associations with biological and environmental measures. These findings suggest that smoking mothers can provide reliable and valid reports of the degree to which their infants are exposed to SHS.

Reducing children's exposure to environmental tobacco smoke: the empirical evidence and directions for future research.

OBJECTIVE: To summarise the issues and empirical evidence for reduction of children's residential environmental tobacco smoke (ETS) exposure. DATA SOURCES: Literature was obtained by computer search, with emphasis on studies that included quantitative measures of ETS exposure in children's residences and interventions based on social learning theory. STUDY SELECTION: Review and empirical articles concerning ETS exposure were included and inferences were drawn based on a synthesis of these studies as contrasted with a quantitative meta-analysis. DATA SYNTHESIS: Interventions designed for residential/child ETS exposure control have included policy/legal regulations, minimal clinical services, and counselling services. Divorce court and adoption services have limited custody to protect children from ETS exposure. Controlled trials of clinicians' one time counselling services have shown null results. One controlled trial found that repeated physician ETS counselling increased parent cessation. Three trials found that repeated counselling/shaping procedures reduced quantitative estimates of ETS exposure in asthmatic children. CONCLUSIONS: Insufficient controlled studies of repeated session counselling procedures have been completed to determine efficacy for ETS exposure reduction, but evidence is promising. One time minimal interventions appear ineffective, but large scale studies may be warranted. No studies have been conducted to assess court or adoption agency regulations; no community ordinances for regulating residential ETS exposure have been invoked. Ethical and enforcement issues are discussed.

Measuring environmental tobacco smoke exposure in infants and young children through urine cotinine and memory-based parental reports: empirical findings and discussion.

OBJECTIVE: This study examined the reliability and potential biases of two urine collection methods from which cotinine measures were obtained and the validity of memory-based parental reports of their children's exposure to environmental tobacco smoke (ETS). DESIGN: Structured interviews were conducted with mothers of infants and young children to obtain memory-based estimates of recent ETS exposure. Urine samples were collected through standard and cotton roll collection methods for cotinine analysis. SETTING: All interviews took place at an off-campus research facility. Urine samples were collected at the study office or the subjects' homes. PARTICIPANTS: Mothers were recruited from San Diego county sites of the Women, Infants, and Children (WIC) Supplemental Food and Nutrition Program. Sample 1 (infants) consisted of eight boys and eight girls aged 1-44 months (mean = 12.6 months). Sample 2 (children) included 10 boys and 10 girls aged 3-8 years (mean = 61.2 months). MAIN OUTCOME MEASURES: Urine cotinine and memory-based parent reports of ETS exposure from structured interviews. RESULTS: There was overall high reliability for urine cotinine measures and no effect of collection method on urine cotinine levels. Memory-based reports obtained from smoking mothers showed moderately strong and consistent linear relationships with urine cotinine measures of their infants and children (r = 0.50 to r = 0.63), but not for reports obtained from non-smoking mothers. CONCLUSIONS: Memory-based parental reports of short-term ETS exposure can play an important role in quantifying ETS exposure in infants and children.

Toward a simplified measure of asthma severity for applied research.

There is no universally accepted and validated measure of asthma severity. For community research, clinical tests are too costly, and epidemiological assessments provide inadequate data on severity. Symptom measures may offer a practical alternative. This study assessed psychometric properties of symptom ratings of 91 asthmatic children. Reliability and validity of scales created from these items were examined. A sum scale of symptom ratings was internally consistent, reliable across time, and associated with concurrent health indices. This scale may be a practical measure of severity for use in community-based research.

Reduction of environmental tobacco smoke exposure in asthmatic children. A 2-year follow-up.

STUDY OBJECTIVE: To examine the long-term maintenance of a previously reported behavioral counseling intervention to reduce asthmatic children's exposure to environmental tobacco smoke (ETS). PARTICIPANTS: Families of asthmatic children (6 to 17 years), including at least one parent who smoked in the home, recruited from four pediatric allergy clinics. DESIGN: Participants were randomized to one of three groups: behavioral counseling to reduce ETS exposure, self-monitoring control, and usual medical care control. Counseling concluded at month 6, and the original trial ended at month 12. Two follow-up interviews occurred at months 20 and 30. MEASUREMENTS AND RESULTS: The originally reported analysis of baseline to 12 months was reanalyzed with a more robust restricted maximum likelihood procedure. The 2-year follow-up period was analyzed similarly. Significantly greater change occurred in the counseling group than the control groups and was sustained throughout the 2 years of follow-up. Further exploratory analyses suggested that printed counseling materials given to all participants at month 12 (conclusion of the original study) were associated with decreased exposure in the control groups. CONCLUSION: Such long-term maintenance of behavior change is highly unusual in the general behavioral science literature, let alone for addictive behaviors. We conclude that ETS exposure can be reduced and that a clinician-delivered treatment may provide substantial benefit.

Ethnic, socioeconomic, and sex differences in physical activity among adolescents.

Regular physical activity is recommended for health maintenance in adolescence, but basic descriptive epidemiological data are lacking for this age group. The present study examined socioeconomic status (SES), ethnic, and sex differences in physical activity in a multiethnic sample of 1871 high school students in San Diego, California. Surveys were completed in required classes by a diverse sample of students from a low-income school district and by Anglo students from a nearby more affluent district. Boys reported more vigorous exercise outside of school and during school physical education, as well as more participation in sports teams, but girls reported taking more activity-related lessons and classes. High-SES students had more frequent physical education classes, spent more time in vigorous exercise in those classes, and participated in more activity lessons outside of school. There were few ethnic differences on summary physical activity or physical education variables. There were no SES differences, but there were ethnic differences on 5 of 22 specific activities. Demographic differences in 25 psychological, social, and environmental variables that may influence physical activity were also examined. Differences between boys and girls were found on several variables, which may explain some of the boys' higher activity levels. Ethnic and/or SES differences were found in 10 of 25 potential correlates of physical activity. These data may be used to identify specific activities that may be preferred by subgroups of adolescents and specific mediating variables that can be targeted in physical activity promotion programs for adolescents.

The accuracy of environmental tobacco smoke exposure measures among asthmatic children.

This study determined the reliability and validity of parent-reported measures of environmental tobacco smoke (ETS) exposure among 91 asthmatic children. Test-retest reliability assessments were conducted for environmental, biological and parent-reported measures of ETS exposure. All measures except a urine cotinine assay resulted in satisfactory levels of reliability. The parent-reported measures of ETS exposure were compared to the environmental filter measure of nicotine as well as submitted to a construct validity test. Parent-reported home exposure to ETS proved moderately and significantly correlated to the filter measure. Approximately 80% of all hypothetical constructs agreed with the observed relationships for convergent, divergent and discriminant validity. It was concluded that middle class Caucasian parents' reports of their asthmatic child's residential ETS exposure are reliable and valid. These parent-reported measures should be valuable tools for epidemiological investigations and for clinical programs designed to reduce asthmatic children's residential exposure to ETS.

Parent smoking and asthmatic children's exposure patterns: a behavioral epidemiology study.

Exposure of nonsmokers to environmental tobacco smoke (ETS) has become an important public health issue; it is generally agreed that increased exposure is related to morbidity and mortality. Precise prevalence estimates of exposure are not yet available, and measurement methodology for ETS exposure rates is still in its formative stage. Recent interventions have attempted to reduce ETS exposure, particularly in children of smoking parents. Studies have relied primarily upon reduction of parents' smoking rates to indirectly reduce children's ETS exposure. In order to effectively design interventions to achieve reductions in ETS exposure, more attention must be given to smoking behaviors which lead to passive exposure. Ninety-one families with at least one smoking parent and an asthmatic child were recruited from four allergy clinics, and interviewed regarding their smoking history, current residential smoking patterns, and the children's exposure patterns. Descriptive data are presented. It is striking that the most smoking and most exposure did not occur in the same locations, times, or during the same activities. It is recommended that interventions focus closely on these patterns rather than on reduction of smoking rates alone, in order to effect reduction in ETS exposure.

Reduction of environmental tobacco smoke exposure among asthmatic children: a controlled trial.

STUDY OBJECTIVE: This randomized clinical trial tested a behavioral medicine program designed to reduce asthmatic children's exposure to environmental tobacco smoke (ETS) in the home. DESIGN: Families were randomly assigned to an experimental preventive medicine counseling group, a monitoring control group, or a usual treatment control group. Families were measured six times over 1 year. PARTICIPANTS: Ninety-one families were recruited from four allergy clinics. INTERVENTION: The experimental group received a 6-month series of counseling sessions designed to decrease ETS exposure. This group also monitored smoking, exposure, and children's asthma symptoms. The monitoring group did not receive counseling and the usual treatment control group received outcome measures only. MEASUREMENTS AND RESULTS: Parents reported the daily number of cigarettes children were exposed to during the week preceding interviews. A nicotine air monitor and construct validity analysis confirmed the validity of exposure reports. Exposure to the parent's cigarettes in the home decreased for all groups. The experimental group attained a 79 percent decrease in children's ETS exposure, compared with 42 percent for the monitoring control and 34 percent for the usual treatment control group. Repeated-measures analysis of variance resulted in a significant (F([10,350] = 1.92, p < 0.05) group by time effect. At the final 12-month visit, the experimental/counseling group sustained a 51% decrease in children's exposure to cigarettes in the home from all smokers, while the monitoring control group showed an 18% decrease and the usual treatment control group a 15% decrease from pre-intervention [corrected]. CONCLUSION: A behavioral medicine program was successful in reducing exposure to ETS in the home for these asthmatic children.

Correlates of vigorous exercise in a predominantly low SES and minority high school population.

BACKGROUND: This study identifies correlates of vigorous exercise among minority and low-socioeconomic-status adolescents. METHODS: Ninth and 11th grade students completed 1,634 questionnaires regarding vigorous exercise and possible correlates. RESULTS: While 76% of students participated in vigorous exercise 3 or more times per week (the year 2000 goal for the nation), only 55% participated in vigorous exercise 3 or more times per week outside of school. A substantial minority of students (20%) did not participate in any vigorous exercise outside of school, and 11% did not participate in any vigorous exercise at all. Males and 9th graders participated in significantly more vigorous exercise than did females and 11th graders both in school physical education and outside of school. Hierarchical multiple regression analyses with 28 independent variables were computed separately for males (R = 0.44, F(28,625) = 5.27, P < 0.001) and females (R = 0.45, F(28,622) = 5.56, P < 0.001). Correlates were similar for both groups and included self-efficacy, family, and friend support. CONCLUSIONS: Results suggest that among minority and lower socioeconomic status adolescents the prevalence of vigorous exercise decreases with age or when students are not required to participate in school physical education and that social factors may be instrumental for sustaining vigorous exercise.